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| * tracing: Add stack_tracer_disable/enable() functionsSteven Rostedt (VMware)2017-04-101-0/+32
| | | | | | | | | | | | | | | | | | | | | | There are certain parts of the kernel that cannot let stack tracing proceed (namely in RCU), because the stack tracer uses RCU, and parts of RCU internals cannot handle having RCU read side locks taken. Add stack_tracer_disable() and stack_tracer_enable() functions to let RCU stop stack tracing on the current CPU when it is in those critical sections. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing: Replace the per_cpu() with __this_cpu*() in trace_stack.cSteven Rostedt (VMware)2017-04-101-16/+7
| | | | | | | | | | | | | | | | | | | | | | The updates to the trace_active per cpu variable can be updated with the __this_cpu_*() functions as it only gets updated on the CPU that the variable is on. Thanks to Paul McKenney for suggesting __this_cpu_* instead of this_cpu_*. Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Add use of synchronize_rcu_tasks() with dynamic trampolinesSteven Rostedt (VMware)2017-04-072-25/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function tracer needs to be more careful than other subsystems when it comes to freeing data. Especially if that data is actually executable code. When a single function is traced, a trampoline can be dynamically allocated which is called to jump to the function trace callback. When the callback is no longer needed, the dynamic allocated trampoline needs to be freed. This is where the issues arise. The dynamically allocated trampoline must not be used again. As function tracing can trace all subsystems, including subsystems that are used to serialize aspects of freeing (namely RCU), it must take extra care when doing the freeing. Before synchronize_rcu_tasks() was around, there was no way for the function tracer to know that nothing was using the dynamically allocated trampoline when CONFIG_PREEMPT was enabled. That's because a task could be indefinitely preempted while sitting on the trampoline. Now with synchronize_rcu_tasks(), it will wait till all tasks have either voluntarily scheduled (not on the trampoline) or goes into userspace (not on the trampoline). Then it is safe to free the trampoline even with CONFIG_PREEMPT set. Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing/kprobes: expose maxactive for kretprobe in kprobe_eventsAlban Crequy2017-04-041-6/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a kretprobe is installed on a kernel function, there is a maximum limit of how many calls in parallel it can catch (aka "maxactive"). A kernel module could call register_kretprobe() and initialize maxactive (see example in samples/kprobes/kretprobe_example.c). But that is not exposed to userspace and it is currently not possible to choose maxactive when writing to /sys/kernel/debug/tracing/kprobe_events The default maxactive can be as low as 1 on single-core with a non-preemptive kernel. This is too low and we need to increase it not only for recursive functions, but for functions that sleep or resched. This patch updates the format of the command that can be written to kprobe_events so that maxactive can be optionally specified. I need this for a bpf program attached to the kretprobe of inet_csk_accept, which can sleep for a long time. This patch includes a basic selftest: > # ./ftracetest -v test.d/kprobe/ > === Ftrace unit tests === > [1] Kprobe dynamic event - adding and removing [PASS] > [2] Kprobe dynamic event - busy event check [PASS] > [3] Kprobe dynamic event with arguments [PASS] > [4] Kprobes event arguments with types [PASS] > [5] Kprobe dynamic event with function tracer [PASS] > [6] Kretprobe dynamic event with arguments [PASS] > [7] Kretprobe dynamic event with maxactive [PASS] > > # of passed: 7 > # of failed: 0 > # of unresolved: 0 > # of untested: 0 > # of unsupported: 0 > # of xfailed: 0 > # of undefined(test bug): 0 BugLink: https://github.com/iovisor/bcc/issues/1072 Link: http://lkml.kernel.org/r/1491215782-15490-1-git-send-email-alban@kinvolk.io Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Alban Crequy <alban@kinvolk.io> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Have init/main.c call ftrace directly to free init memorySteven Rostedt (VMware)2017-04-031-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Relying on free_reserved_area() to call ftrace to free init memory proved to not be sufficient. The issue is that on x86, when debug_pagealloc is enabled, the init memory is not freed, but simply set as not present. Since ftrace was uninformed of this, starting function tracing still tries to update pages that are not present according to the page tables, causing ftrace to bug, as well as killing the kernel itself. Instead of relying on free_reserved_area(), have init/main.c call ftrace directly just before it frees the init memory. Then it needs to use __init_begin and __init_end to know where the init memory location is. Looking at all archs (and testing what I can), it appears that this should work for each of them. Reported-by: kernel test robot <xiaolong.ye@intel.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Create separate t_func_next() to simplify the function / hash logicSteven Rostedt (VMware)2017-03-311-14/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed that if I use dd to read the set_ftrace_filter file that the first hash command is repeated. # cd /sys/kernel/debug/tracing # echo schedule > set_ftrace_filter # echo do_IRQ >> set_ftrace_filter # echo schedule:traceoff >> set_ftrace_filter # echo do_IRQ:traceoff >> set_ftrace_filter # cat set_ftrace_filter schedule do_IRQ schedule:traceoff:unlimited do_IRQ:traceoff:unlimited # dd if=set_ftrace_filter bs=1 schedule do_IRQ schedule:traceoff:unlimited schedule:traceoff:unlimited do_IRQ:traceoff:unlimited 98+0 records in 98+0 records out 98 bytes copied, 0.00265011 s, 37.0 kB/s This is due to the way t_start() calls t_next() as well as the seq_file calls t_next() and the state is slightly different between the two. Namely, t_start() will call t_next() with a local "pos" variable. By separating out the function listing from t_next() into its own function, we can have better control of outputting the functions and the hash of triggers. This simplifies the code. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Update func_pos in t_start() when all functions are enabledSteven Rostedt (VMware)2017-03-311-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If all functions are enabled, there's a comment displayed in the file to denote that: # cd /sys/kernel/debug/tracing # cat set_ftrace_filter #### all functions enabled #### If a function trigger is set, those are displayed as well: # echo schedule:traceoff >> /debug/tracing/set_ftrace_filter # cat set_ftrace_filter #### all functions enabled #### schedule:traceoff:unlimited But if you read that file with dd, the output can change: # dd if=/debug/tracing/set_ftrace_filter bs=1 #### all functions enabled #### 32+0 records in 32+0 records out 32 bytes copied, 7.0237e-05 s, 456 kB/s This is because the "pos" variable is updated for the comment, but func_pos is not. "func_pos" is used by the triggers (or hashes) to know how many functions were printed and it bases its index from the pos - func_pos. func_pos should be 1 to count for the comment printed. But since it is not, t_hash_start() thinks that one trigger was already printed. The cat gets to t_hash_start() via t_next() and not t_start() which updates both pos and func_pos. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Return NULL at end of t_start() instead of calling t_hash_start()Steven Rostedt (VMware)2017-03-311-1/+1
| | | | | | | | | | | | | | | | The loop in t_start() of calling t_next() will call t_hash_start() if the pos is beyond the functions and enters the hash items. There's no reason to check if p is NULL and call t_hash_start(), as that would be redundant. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Assign iter->hash to filter or notrace hashes on seq readSteven Rostedt (VMware)2017-03-311-12/+9
| | | | | | | | | | | | | | | | | | Instead of testing if the hash to use is the filter_hash or the notrace_hash at each iteration, do the test at open, and set the iter->hash to point to the corresponding filter or notrace hash. Then use that directly instead of testing which hash needs to be used each iteration. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Clean up __seq_open_private() return checkSteven Rostedt (VMware)2017-03-311-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The return status check of __seq_open_private() is rather strange: iter = __seq_open_private(); if (iter) { /* do stuff */ } return iter ? 0 : -ENOMEM; It makes much more sense to do the return of failure right away: iter = __seq_open_private(); if (!iter) return -ENOMEM; /* do stuff */ return 0; This clean up will make updates to this code a bit nicer. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing: Move trace_handle_return() out of lineSteven Rostedt (VMware)2017-03-241-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently trace_handle_return() looks like this: static inline enum print_line_t trace_handle_return(struct trace_seq *s) { return trace_seq_has_overflowed(s) ? TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED; } Where trace_seq_overflowed(s) is: static inline bool trace_seq_has_overflowed(struct trace_seq *s) { return s->full || seq_buf_has_overflowed(&s->seq); } And seq_buf_has_overflowed(&s->seq) is: static inline bool seq_buf_has_overflowed(struct seq_buf *s) { return s->len > s->size; } Making trace_handle_return() into: return (s->full || (s->seq->len > s->seq->size)) ? TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED; One would think this is not an issue to keep as an inline. But because this is used in the TRACE_EVENT() macro, it is extended for every tracepoint in the system. Taking a look at a single tracepoint x86_irq_vector (was the first one I randomly chosen). As trace_handle_return is used in the TRACE_EVENT() macro of trace_raw_output_##call() we disassemble trace_raw_output_x86_irq_vector and do a diff: - is the original + is the out-of-line code I removed identical lines that were different just due to different addresses. --- /tmp/irq-vec-orig 2017-03-16 09:12:48.569384851 -0400 +++ /tmp/irq-vec-ool 2017-03-16 09:13:39.378153385 -0400 @@ -6,27 +6,23 @@ 53 push %rbx 48 89 fb mov %rdi,%rbx 4c 8b a7 c0 20 00 00 mov 0x20c0(%rdi),%r12 e8 f7 72 13 00 callq ffffffff81155c80 <trace_raw_output_prep> 83 f8 01 cmp $0x1,%eax 74 05 je ffffffff8101e993 <trace_raw_output_x86_irq_vector+0x23> 5b pop %rbx 41 5c pop %r12 5d pop %rbp c3 retq 41 8b 54 24 08 mov 0x8(%r12),%edx - 48 8d bb 98 10 00 00 lea 0x1098(%rbx),%rdi + 48 81 c3 98 10 00 00 add $0x1098,%rbx - 48 c7 c6 7b 8a a0 81 mov $0xffffffff81a08a7b,%rsi + 48 c7 c6 ab 8a a0 81 mov $0xffffffff81a08aab,%rsi - e8 c5 85 13 00 callq ffffffff81156f70 <trace_seq_printf> === here's the start of the main difference === + 48 89 df mov %rbx,%rdi + e8 62 7e 13 00 callq ffffffff81156810 <trace_seq_printf> - 8b 93 b8 20 00 00 mov 0x20b8(%rbx),%edx - 31 c0 xor %eax,%eax - 85 d2 test %edx,%edx - 75 11 jne ffffffff8101e9c8 <trace_raw_output_x86_irq_vector+0x58> - 48 8b 83 a8 20 00 00 mov 0x20a8(%rbx),%rax - 48 39 83 a0 20 00 00 cmp %rax,0x20a0(%rbx) - 0f 93 c0 setae %al + 48 89 df mov %rbx,%rdi + e8 4a c5 12 00 callq ffffffff8114af00 <trace_handle_return> 5b pop %rbx - 0f b6 c0 movzbl %al,%eax === end === 41 5c pop %r12 5d pop %rbp c3 retq If you notice, the original has 22 bytes of text more than the out of line version. As this is for every TRACE_EVENT() defined in the system, this can become quite large. text data bss dec hex filename 8690305 5450490 1298432 15439227 eb957b vmlinux-orig 8681725 5450490 1298432 15430647 eb73f7 vmlinux-handle This change has a total of 8580 bytes in savings. $ objdump -dr /tmp/vmlinux-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l 324 That's 324 tracepoints. But this does not include modules (which contain many more tracepoints). For an allyesconfig build: $ objdump -dr vmlinux-allyes-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l 1401 That's 1401 tracepoints giving us: text data bss dec hex filename 137920629 140221067 53264384 331406080 13c0db00 vmlinux-allyes-orig 137827709 140221067 53264384 331313160 13bf7008 vmlinux-allyes-handle 92920 bytes in savings!!! Link: http://lkml.kernel.org/r/20170315021431.13107-2-andi@firstfloor.org Reported-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Allow for function tracing to record init functions on boot upSteven Rostedt (VMware)2017-03-241-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding a hook into free_reserve_area() that informs ftrace that boot up init text is being free, lets ftrace safely remove those init functions from its records, which keeps ftrace from trying to modify text that no longer exists. Note, this still does not allow for tracing .init text of modules, as modules require different work for freeing its init code. Link: http://lkml.kernel.org/r/1488502497.7212.24.camel@linux.intel.com Cc: linux-mm@kvack.org Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Requested-by: Todd Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * ftrace: Have function tracing start in early boot upSteven Rostedt (VMware)2017-03-243-2/+6
| | | | | | | | | | | | | | | | Register the function tracer right after the tracing buffers are initialized in early boot up. This will allow function tracing to begin early if it is enabled via the kernel command line. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing: Postpone tracer start-up tests till the system is more robustSteven Rostedt (VMware)2017-03-241-0/+71
| | | | | | | | | | | | | | | | | | | | As tracing can now be enabled very early in boot up, even before some critical system services (like scheduling), do not run the tracer selftests until after early_initcall() is performed. If a tracer is registered before such time, it is saved off in a list and the test is run when the system is able to handle more diverse functions. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * tracing: Split tracing initialization into two for early initializationSteven Rostedt (VMware)2017-03-241-1/+5
| | | | | | | | | | | | | | | | Create an early_trace_init() function that will initialize the buffers and allow for ealier use of trace_printk(). This will also allow for future work to have function tracing start earlier at boot up. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2017-05-021-27/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Millar: "Here are some highlights from the 2065 networking commits that happened this development cycle: 1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri) 2) Add a generic XDP driver, so that anyone can test XDP even if they lack a networking device whose driver has explicit XDP support (me). 3) Sparc64 now has an eBPF JIT too (me) 4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei Starovoitov) 5) Make netfitler network namespace teardown less expensive (Florian Westphal) 6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana) 7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger) 8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky) 9) Multiqueue support in stmmac driver (Joao Pinto) 10) Remove TCP timewait recycling, it never really could possibly work well in the real world and timestamp randomization really zaps any hint of usability this feature had (Soheil Hassas Yeganeh) 11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay Aleksandrov) 12) Add socket busy poll support to epoll (Sridhar Samudrala) 13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso, and several others) 14) IPSEC hw offload infrastructure (Steffen Klassert)" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits) tipc: refactor function tipc_sk_recv_stream() tipc: refactor function tipc_sk_recvmsg() net: thunderx: Optimize page recycling for XDP net: thunderx: Support for XDP header adjustment net: thunderx: Add support for XDP_TX net: thunderx: Add support for XDP_DROP net: thunderx: Add basic XDP support net: thunderx: Cleanup receive buffer allocation net: thunderx: Optimize CQE_TX handling net: thunderx: Optimize RBDR descriptor handling net: thunderx: Support for page recycling ipx: call ipxitf_put() in ioctl error path net: sched: add helpers to handle extended actions qed*: Fix issues in the ptp filter config implementation. qede: Fix concurrency issue in PTP Tx path processing. stmmac: Add support for SIMATIC IOT2000 platform net: hns: fix ethtool_get_strings overflow in hns driver tcp: fix wraparound issue in tcp_lp bpf, arm64: fix jit branch offset related to ldimm64 bpf, arm64: implement jiting of BPF_XADD ...
| * \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-04-212-5/+19
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both conflict were simple overlapping changes. In the kaweth case, Eric Dumazet's skb_cow() bug fix overlapped the conversion of the driver in net-next to use in-netdev stats. Signed-off-by: David S. Miller <davem@davemloft.net>
| * \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-04-203-4/+28
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A function in kernel/bpf/syscall.c which got a bug fix in 'net' was moved to kernel/bpf/verifier.c in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * \ \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-04-151-4/+4
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts were simply overlapping changes. In the net/ipv4/route.c case the code had simply moved around a little bit and the same fix was made in both 'net' and 'net-next'. In the net/sched/sch_generic.c case a fix in 'net' happened at the same time that a new argument was added to qdisc_hash_add(). Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | | bpf: remove struct bpf_prog_type_listJohannes Berg2017-04-111-27/+3
| | |_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no need to have struct bpf_prog_type_list since it just contains a list_head, the type, and the ops pointer. Since the types are densely packed and not actually dynamically registered, it's much easier and smaller to have an array of type->ops pointer. Also initialize this array statically to remove code needed to initialize it. In order to save duplicating the list, move it to a new header file and include it in the places needing it. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | | Merge branch 'work.splice' of ↵Linus Torvalds2017-05-021-2/+0
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice updates from Al Viro: "These actually missed the last cycle; the branch itself is from last December" * 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: make nr_pages calculation in default_file_splice_read() a bit less ugly splice/tee/vmsplice: validate flags splice_pipe_desc: kill ->flags remove spd_release_page()
| * | | | | splice_pipe_desc: kill ->flagsAl Viro2016-12-261-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | no users left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2017-05-013-7/+5
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main changes in this cycle were: Kernel side changes: - Kprobes and uprobes changes: - Make their trampolines read-only while they are used - Make UPROBES_EVENTS default-y which is the distro practice - Apply misc fixes and robustization to probe point insertion. - add support for AMD IOMMU events - extend hw events on Intel Goldmont CPUs - ... plus misc fixes and updates. Tooling side changes: - support s390 jump instructions in perf annotate (Christian Borntraeger) - vendor hardware events updates (Andi Kleen) - add argument support for SDT events in powerpc (Ravi Bangoria) - beautify the statx syscall arguments in 'perf trace' (Arnaldo Carvalho de Melo) - handle inline functions in callchains (Jin Yao) - enable sorting by srcline as key (Milian Wolff) - add 'brstackinsn' field in 'perf script' to reuse the x86 instruction decoder used in the Intel PT code to study hot paths to samples (Andi Kleen) - add PERF_RECORD_NAMESPACES so that the kernel can record information required to associate samples to namespaces, helping in container problem characterization. (Hari Bathini) - allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis) - in perf stat, make system wide (-a) the default option if no target was specified and one of following conditions is met: - no workload specified (current behaviour) - a workload is specified but all requested events are system wide ones, like uncore ones. (Jiri Olsa) - ... plus lots of other updates, enhancements, cleanups and fixes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (235 commits) perf tools: Fix the code to strip command name tools arch x86: Sync cpufeatures.h tools arch: Sync arch/x86/lib/memcpy_64.S with the kernel tools: Update asm-generic/mman-common.h copy from the kernel perf tools: Use just forward declarations for struct thread where possible perf tools: Add the right header to obtain PERF_ALIGN() perf tools: Remove poll.h and wait.h from util.h perf tools: Remove string.h, unistd.h and sys/stat.h from util.h perf tools: Remove stale prototypes from builtin.h perf tools: Remove string.h from util.h perf tools: Remove sys/ioctl.h from util.h perf tools: Remove a few more needless includes from util.h perf tools: Include sys/param.h where needed perf callchain: Move callchain specific routines from util.[ch] perf tools: Add compress.h for the *_decompress_to_file() headers perf mem: Fix display of data source snoop indication perf debug: Move dump_stack() and sighandler_dump_stack() to debug.h perf kvm: Make function only used by 'perf kvm' static perf tools: Move timestamp routines from util.h to time-utils.h perf tools: Move units conversion/formatting routines to separate object ...
| * \ \ \ \ \ Merge tag 'v4.11-rc6' into perf/core, to pick up fixesIngo Molnar2017-04-111-4/+4
| |\ \ \ \ \ \ | | | |_|/ / / | | |/| | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge tag 'perf-core-for-mingo-4.12-20170316' of ↵Ingo Molnar2017-03-162-2/+2
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: New features: - Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction decoder used in the Intel PT code to study hot paths to samples (Andi Kleen) Kernel changes: - Default UPROBES_EVENTS to Y (Alexei Starovoitov) - Fix check for kretprobe offset within function entry (Naveen N. Rao) Infrastructure changes: - Introduce util func is_sdt_event() (Ravi Bangoria) - Make perf_event__synthesize_mmap_events() scale on older kernels where reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | uprobes: Default UPROBES_EVENTS to YArnaldo Carvalho de Melo2017-03-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As it is already turned on by most distros, so just flip the default to Y. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Wang Nan <wangnan0@huawei.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: David Miller <davem@davemloft.net> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170316005817.GA6805@ast-mbp.thefacebook.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | | | trace/kprobes: Fix check for kretprobe offset within function entryNaveen N. Rao2017-03-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf specifies an offset from _text and since this offset is fed directly into the arch-specific helper, kprobes tracer rejects installation of kretprobes through perf. Fix this by looking up the actual offset from a function for the specified sym+offset. Refactor and reuse existing routines to limit code duplication -- we repurpose kprobe_addr() for determining final kprobe address and we split out the function entry offset determination into a separate generic helper. Before patch: naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return probe-definition(0): do_open%return symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /boot/vmlinux for symbols Open Debuginfo file: /boot/vmlinux Try to find probe point from debuginfo. Matched function: do_open [2d0c7ff] Probe point found: do_open+0 Matched function: do_open [35d76dc] found inline addr: 0xc0000000004ba9c4 Failed to find "do_open%return", because do_open is an inlined function and has no return point. An error occurred in debuginfo analysis (-22). Trying to use symbols. Opening /sys/kernel/debug/tracing//README write=0 Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: r:probe/do_open _text+4469776 Failed to write event: Invalid argument Error: Failed to add events. Reason: Invalid argument (Code: -22) naveen@ubuntu:~/linux/tools/perf$ dmesg | tail <snip> [ 33.568656] Given offset is not valid for return probe. After patch: naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return probe-definition(0): do_open%return symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /boot/vmlinux for symbols Open Debuginfo file: /boot/vmlinux Try to find probe point from debuginfo. Matched function: do_open [2d0c7d6] Probe point found: do_open+0 Matched function: do_open [35d76b3] found inline addr: 0xc0000000004ba9e4 Failed to find "do_open%return", because do_open is an inlined function and has no return point. An error occurred in debuginfo analysis (-22). Trying to use symbols. Opening /sys/kernel/debug/tracing//README write=0 Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: r:probe/do_open _text+4469808 Writing event: r:probe/do_open_1 _text+4956344 Added new events: probe:do_open (on do_open%return) probe:do_open_1 (on do_open%return) You can now use it in all perf tools, such as: perf record -e probe:do_open_1 -aR sleep 1 naveen@ubuntu:~/linux/tools/perf$ sudo cat /sys/kernel/debug/kprobes/list c000000000041370 k kretprobe_trampoline+0x0 [OPTIMIZED] c0000000004ba0b8 r do_open+0x8 [DISABLED] c000000000443430 r do_open+0x0 [DISABLED] Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/d8cd1ef420ec22e3643ac332fdabcffc77319a42.1488961018.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | | Merge branch 'linus' into perf/core, to pick up fixesIngo Molnar2017-03-162-6/+19
| |\ \ \ \ \ \ \ | | |/ / / / / / | |/| | | / / / | | | |_|/ / / | | |/| | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge tag 'perf-core-for-mingo-4.11-20170306' of ↵Ingo Molnar2017-03-075-18/+16
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: New features: - Allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis) E.g.: # perf report -s symbol_size,symbol Samples: 9K of event 'cycles:k', Event count (approx.): 2870461623 Overhead Symbol size Symbol 14.55% 326 [k] flush_tlb_mm_range 7.20% 1045 [k] filemap_map_pages 5.82% 124 [k] vma_interval_tree_insert 5.18% 2430 [k] unmap_page_range 2.57% 571 [k] vma_interval_tree_remove 1.94% 494 [k] page_add_file_rmap 1.82% 740 [k] page_remove_rmap 1.66% 1017 [k] release_pages 1.57% 1636 [k] update_blocked_averages 1.57% 76 [k] unlock_page - Add support for -p/--pid, -a/--all-cpus and -C/--cpu in 'perf ftrace' (Namhyung Kim) Change in behaviour: - Make system wide (-a) the default option if no target was specified and one of following conditions is met: - No workload specified (current behaviour) - A workload is specified but all requested events are system wide ones, like uncore ones. (Jiri Olsa) Fixes: - Add missing initialization to the instruction decoder used in the intel PT/BTS code, which was causing lots of failures in 'perf test', looking for a value when there was none (Adrian Hunter) Infrastructure changes: - Add arch code needed to adopt the kernel's refcount_t to aid in catching bugs when using atomic_t as a reference counter, basically cmpxchg related functions (Arnaldo Carvalho de Melo) - Convert the code using atomic_t as reference counts to refcount_t (Elena Rashetova) - Add feature test for sched_getcpu() to more easily check for its presence in the many libc implementations and accross different versions of such C libraries (Arnaldo Carvalho de Melo) - Issue a HW watchdog disable hint in 'perf stat' for when some of the requested events can't get counted because a PMU counter is taken by that watchdog (Borislav Petkov). - Add mapping for Intel's KnightsMill PMU events (Karol Wachowski) Documentation changes: - Clarify the term 'convergence' in: perf bench numa numa-mem -h --show_convergence (Jiri Olsa) Kernel code changes: - Ensure probe location is at function entry in kretprobes (Naveen N. Rao) - Allow return probes with offsets and absolute addresses (Naveen N. Rao) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | trace/kprobes: Add back warning about offset in return probesSteven Rostedt (VMware)2017-03-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's not remove the warning about offsets and return probes when the offset is invalid. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170227115204.00f92846@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | | | trace/kprobes: Allow return probes with offsets and absolute addressesNaveen N. Rao2017-03-032-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the kernel includes many non-global functions with same names, we will need to use offsets from other symbols (typically _text/_stext) or absolute addresses to place return probes on specific functions. Also, the core register_kretprobe() API never forbid use of offsets or absolute addresses with kretprobes. Allow its use with the trace infrastructure. To distinguish kernels that support this, update ftrace README to explicitly call this out. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/183e7ce2921a08c9c755ee9a5da3134febc6695b.1487770934.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | | | | | | Merge branch 'work.uaccess' of ↵Linus Torvalds2017-05-011-1/+1
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uaccess unification updates from Al Viro: "This is the uaccess unification pile. It's _not_ the end of uaccess work, but the next batch of that will go into the next cycle. This one mostly takes copy_from_user() and friends out of arch/* and gets the zero-padding behaviour in sync for all architectures. Dealing with the nocache/writethrough mess is for the next cycle; fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am sold on access_ok() in there, BTW; just not in this pile), same for reducing __copy_... callsites, strn*... stuff, etc. - there will be a pile about as large as this one in the next merge window. This one sat in -next for weeks. -3KLoC" * 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits) HAVE_ARCH_HARDENED_USERCOPY is unconditional now CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now m32r: switch to RAW_COPY_USER hexagon: switch to RAW_COPY_USER microblaze: switch to RAW_COPY_USER get rid of padding, switch to RAW_COPY_USER ia64: get rid of copy_in_user() ia64: sanitize __access_ok() ia64: get rid of 'segment' argument of __do_{get,put}_user() ia64: get rid of 'segment' argument of __{get,put}_user_check() ia64: add extable.h powerpc: get rid of zeroing, switch to RAW_COPY_USER esas2r: don't open-code memdup_user() alpha: fix stack smashing in old_adjtimex(2) don't open-code kernel_setsockopt() mips: switch to RAW_COPY_USER mips: get rid of tail-zeroing in primitives mips: make copy_from_user() zero tail explicitly mips: clean and reorder the forest of macros... mips: consolidate __invoke_... wrappers ...
| * \ \ \ \ \ \ \ Merge branch 'parisc-4.11-3' of ↵Al Viro2017-04-026-18/+31
| |\ \ \ \ \ \ \ \ | | | |_|/ / / / / | | |/| | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux into uaccess.parisc
| * | | | | | | | new helper: uaccess_kernel()Al Viro2017-03-281-1/+1
| | |/ / / / / / | |/| | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | | | Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-blockLinus Torvalds2017-05-011-23/+12
|\ \ \ \ \ \ \ \ | |_|_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block layer updates from Jens Axboe: - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ was initially a fork of CFQ, but subsequently changed to implement fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant to be used on desktop type single drives, providing good fairness. From Paolo. - Add Kyber IO scheduler. This is a full multiqueue aware scheduler, using a scalable token based algorithm that throttles IO based on live completion IO stats, similary to blk-wbt. From Omar. - A series from Jan, moving users to separately allocated backing devices. This continues the work of separating backing device life times, solving various problems with hot removal. - A series of updates for lightnvm, mostly from Javier. Includes a 'pblk' target that exposes an open channel SSD as a physical block device. - A series of fixes and improvements for nbd from Josef. - A series from Omar, removing queue sharing between devices on mostly legacy drivers. This helps us clean up other bits, if we know that a queue only has a single device backing. This has been overdue for more than a decade. - Fixes for the blk-stats, and improvements to unify the stats and user windows. This both improves blk-wbt, and enables other users to register a need to receive IO stats for a device. From Omar. - blk-throttle improvements from Shaohua. This provides a scalable framework for implementing scalable priotization - particularly for blk-mq, but applicable to any type of block device. The interface is marked experimental for now. - Bucketized IO stats for IO polling from Stephen Bates. This improves efficiency of polled workloads in the presence of mixed block size IO. - A few fixes for opal, from Scott. - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics. From a variety of folks, mostly Sagi and James Smart. - A series from Bart, improving our exposed info and capabilities from the blk-mq debugfs support. - A series from Christoph, cleaning up how handle WRITE_ZEROES. - A series from Christoph, cleaning up the block layer handling of how we track errors in a request. On top of being a nice cleanup, it also shrinks the size of struct request a bit. - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was never used by platforms, and the latter has outlived it's usefulness. - Various little bug fixes and cleanups from a wide variety of folks. * 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits) block: hide badblocks attribute by default blk-mq: unify hctx delay_work and run_work block: add kblock_mod_delayed_work_on() blk-mq: unify hctx delayed_run_work and run_work nbd: fix use after free on module unload MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler blk-mq-sched: alloate reserved tags out of normal pool mtip32xx: use runtime tag to initialize command header scsi: Implement blk_mq_ops.show_rq() blk-mq: Add blk_mq_ops.show_rq() blk-mq: Show operation, cmd_flags and rq_flags names blk-mq: Make blk_flags_show() callers append a newline character blk-mq: Move the "state" debugfs attribute one level down blk-mq: Unregister debugfs attributes earlier blk-mq: Only unregister hctxs for which registration succeeded blk-mq-debugfs: Rename functions for registering and unregistering the mq directory blk-mq: Let blk_mq_debugfs_register() look up the queue name blk-mq: Register <dev>/queue/mq after having registered <dev>/queue ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset ide-pm: always pass 0 error to __blk_end_request_all ..
| * | | | | | | block: remove the errors field from struct requestChristoph Hellwig2017-04-201-14/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | | blktrace: remove the unused block_rq_abort tracepointChristoph Hellwig2017-04-201-9/+0
| | |/ / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | | | | | | ring-buffer: Have ring_buffer_iter_empty() return true when emptySteven Rostedt (VMware)2017-04-191-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed that reading the snapshot file when it is empty no longer gives a status. It suppose to show the status of the snapshot buffer as well as how to allocate and use it. For example: ># cat snapshot # tracer: nop # # # * Snapshot is allocated * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') But instead it just showed an empty buffer: ># cat snapshot # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | What happened was that it was using the ring_buffer_iter_empty() function to see if it was empty, and if it was, it showed the status. But that function was returning false when it was empty. The reason was that the iter header page was on the reader page, and the reader page was empty, but so was the buffer itself. The check only tested to see if the iter was on the commit page, but the commit page was no longer pointing to the reader page, but as all pages were empty, the buffer is also. Cc: stable@vger.kernel.org Fixes: 651e22f2701b ("ring-buffer: Always reset iterator to reader page") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | | | | tracing: Allocate the snapshot buffer before enabling probeSteven Rostedt (VMware)2017-04-191-3/+5
| |_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the snapshot trigger enables the probe and then allocates the snapshot. If the probe triggers before the allocation, it could cause the snapshot to fail and turn tracing off. It's best to allocate the snapshot buffer first, and then enable the trigger. If something goes wrong in the enabling of the trigger, the snapshot buffer is still allocated, but it can also be freed by the user by writting zero into the snapshot buffer file. Also add a check of the return status of alloc_snapshot(). Cc: stable@vger.kernel.org Fixes: 77fd5c15e3 ("tracing: Add snapshot trigger to function probes") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | | | ftrace: Fix function pid filter on instancesNamhyung Kim2017-04-173-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When function tracer has a pid filter, it adds a probe to sched_switch to track if current task can be ignored. The probe checks the ftrace_ignore_pid from current tr to filter tasks. But it misses to delete the probe when removing an instance so that it can cause a crash due to the invalid tr pointer (use-after-free). This is easily reproducible with the following: # cd /sys/kernel/debug/tracing # mkdir instances/buggy # echo $$ > instances/buggy/set_ftrace_pid # rmdir instances/buggy ============================================================================ BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90 Read of size 8 by task kworker/0:1/17 CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G B 4.11.0-rc3 #198 Call Trace: dump_stack+0x68/0x9f kasan_object_err+0x21/0x70 kasan_report.part.1+0x22b/0x500 ? ftrace_filter_pid_sched_switch_probe+0x3d/0x90 kasan_report+0x25/0x30 __asan_load8+0x5e/0x70 ftrace_filter_pid_sched_switch_probe+0x3d/0x90 ? fpid_start+0x130/0x130 __schedule+0x571/0xce0 ... To fix it, use ftrace_clear_pids() to unregister the probe. As instance_rmdir() already updated ftrace codes, it can just free the filter safely. Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org Fixes: 0c8916c34203 ("tracing: Add rmdir to remove multibuffer instances") Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | | | ftrace: Fix removing of second function probeSteven Rostedt (VMware)2017-04-141-4/+16
| |_|_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When two function probes are added to set_ftrace_filter, and then one of them is removed, the update to the function locations is not performed, and the record keeping of the function states are corrupted, and causes an ftrace_bug() to occur. This is easily reproducable by adding two probes, removing one, and then adding it back again. # cd /sys/kernel/debug/tracing # echo schedule:traceoff > set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter # echo \!do_IRQ:traceoff > /debug/tracing/set_ftrace_filter # echo do_IRQ:traceoff > set_ftrace_filter Causes: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1098 at kernel/trace/ftrace.c:2369 ftrace_get_addr_curr+0x143/0x220 Modules linked in: [...] CPU: 2 PID: 1098 Comm: bash Not tainted 4.10.0-test+ #405 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 Call Trace: dump_stack+0x68/0x9f __warn+0x111/0x130 ? trace_irq_work_interrupt+0xa0/0xa0 warn_slowpath_null+0x1d/0x20 ftrace_get_addr_curr+0x143/0x220 ? __fentry__+0x10/0x10 ftrace_replace_code+0xe3/0x4f0 ? ftrace_int3_handler+0x90/0x90 ? printk+0x99/0xb5 ? 0xffffffff81000000 ftrace_modify_all_code+0x97/0x110 arch_ftrace_update_code+0x10/0x20 ftrace_run_update_code+0x1c/0x60 ftrace_run_modify_code.isra.48.constprop.62+0x8e/0xd0 register_ftrace_function_probe+0x4b6/0x590 ? ftrace_startup+0x310/0x310 ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30 ? update_stack_state+0x88/0x110 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? preempt_count_sub+0x18/0xd0 ? mutex_lock_nested+0x104/0x800 ? ftrace_regex_write.isra.43.part.44+0x1d3/0x320 ? __unwind_start+0x1c0/0x1c0 ? _mutex_lock_nest_lock+0x800/0x800 ftrace_trace_probe_callback.isra.3+0xc0/0x130 ? func_set_flag+0xe0/0xe0 ? __lock_acquire+0x642/0x1790 ? __might_fault+0x1e/0x20 ? trace_get_user+0x398/0x470 ? strcmp+0x35/0x60 ftrace_trace_onoff_callback+0x48/0x70 ftrace_regex_write.isra.43.part.44+0x251/0x320 ? match_records+0x420/0x420 ftrace_filter_write+0x2b/0x30 __vfs_write+0xd7/0x330 ? do_loop_readv_writev+0x120/0x120 ? locks_remove_posix+0x90/0x2f0 ? do_lock_file_wait+0x160/0x160 ? __lock_is_held+0x93/0x100 ? rcu_read_lock_sched_held+0x5c/0xb0 ? preempt_count_sub+0x18/0xd0 ? __sb_start_write+0x10a/0x230 ? vfs_write+0x222/0x240 vfs_write+0xef/0x240 SyS_write+0xab/0x130 ? SyS_read+0x130/0x130 ? trace_hardirqs_on_caller+0x182/0x280 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7fe61c157c30 RSP: 002b:00007ffe87890258 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: ffffffff8114a410 RCX: 00007fe61c157c30 RDX: 0000000000000010 RSI: 000055814798f5e0 RDI: 0000000000000001 RBP: ffff8800c9027f98 R08: 00007fe61c422740 R09: 00007fe61ca53700 R10: 0000000000000073 R11: 0000000000000246 R12: 0000558147a36400 R13: 00007ffe8788f160 R14: 0000000000000024 R15: 00007ffe8788f15c ? trace_hardirqs_off_caller+0xc0/0x110 ---[ end trace 99fa09b3d9869c2c ]--- Bad trampoline accounting at: ffffffff81cc3b00 (do_IRQ+0x0/0x150) Cc: stable@vger.kernel.org Fixes: 59df055f1991 ("ftrace: trace different functions with a different tracer") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | | ring-buffer: Fix return value check in test_ringbuffer()Wei Yongjun2017-04-051-4/+4
|/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of error, the function kthread_run() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Link: http://lkml.kernel.org/r/1466184839-14927-1-git-send-email-weiyj_lk@163.com Cc: stable@vger.kernel.org Fixes: 6c43e554a ("ring-buffer: Add ring buffer startup selftest") Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | scripts/spelling.txt: add "overide" pattern and fix typo instancesMasahiro Yamada2017-03-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix typos and add the following to the scripts/spelling.txt: overide||override While we are here, fix the doubled "address" in the touched line Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt. Also, fix the comment block style in the touched hunks in drivers/media/dvb-frontends/drx39xyj/drx_driver.h. Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2017-03-074-12/+12
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This includes a fix for a crash if certain special addresses are kprobed, plus does a rename of two Kconfig variables that were a minor misnomer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS kprobes/x86: Fix kernel panic when certain exception-handling addresses are probed
| * | | perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTSAnton Blanchard2017-03-014-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS. Consistently use the plurals. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: davem@davemloft.net Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge tag 'trace-v4.11-rc1' of ↵Linus Torvalds2017-03-071-5/+18
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "There was some breakage with the changes for jump labels in the 4.11 merge window: - powerpc broke as jump labels uses the two LSB bits as flags in initialization. A check was added to make sure that all jump label entries were 4 bytes aligned, but powerpc didn't work that way for modules. Adding an alignment in the module linker script appeared to be the best solution. - Jump labels also added an anonymous union to access those LSB bits as a normal long. But because this structure had static initialization, it broke older compilers that could not statically initialize anonymous unions without brackets. - The command line parameter for setting function graph filter broke the "EMPTY_HASH" descriptor by modifying it instead of creating a new hash to hold the entries. - The command line parameter ftrace_graph_max_depth was added to allow its setting at boot time. It uses existing code and only the command line hook was added. This is not really a fix, but as it uses existing code without affecting anything else, I added it to this release. It was ready before the merge window closed, but I wanted to let it sit in linux-next for a couple of days first" * tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/graph: Add ftrace_graph_max_depth kernel parameter tracing: Add #undef to fix compile error jump_label: Add comment about initialization order for anonymous unions jump_label: Fix anonymous union initialization module: set __jump_table alignment to 8 ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter tracing: Fix code comment for ftrace_ops_get_func()
| * | | ftrace/graph: Add ftrace_graph_max_depth kernel parameterTodd Brandt2017-03-031-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Early trace callgraphs can be extremely large on systems with several seconds of boot time. The max_depth parameter limits how deep the graph trace goes and reduces the output size. This parameter is the same as the max_graph_depth file in tracefs. Link: http://lkml.kernel.org/r/1488499935-23216-1-git-send-email-todd.e.brandt@linux.intel.com Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com> [ changed comments about debugfs to tracefs ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filterSteven Rostedt (VMware)2017-03-031-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On boot up, if the kernel command line sets a graph funtion with the kernel command line options "ftrace_graph_filter" or "ftrace_graph_notrace" then it updates the corresponding function graph hash, ftrace_graph_hash or ftrace_graph_notrace_hash respectively. Unfortunately, at boot up, these variables are pointers to the "EMPTY_HASH" which is a constant used as a placeholder when a hash has no entities. The problem was that the comand line version to set the hashes updated the actual EMPTY_HASH instead of creating a new hash for the function graph. This broke the EMPTY_HASH because not only did it modify a constant (not sure how that was allowed to happen, except maybe because it was done at early boot, const variables were still mutable), but it made the filters have functions listed in them when they were actually empty. The kernel command line function needs to allocate a new hash for the function graph filters and assign the necessary variables to that new hash instead. Link: http://lkml.kernel.org/r/1488420091.7212.17.camel@linux.intel.com Cc: Namhyung Kim <namhyung@kernel.org> Fixes: b9b0c831bed2 ("ftrace: Convert graph filter to use hash tables") Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com> Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | tracing: Fix code comment for ftrace_ops_get_func()Chunyu Hu2017-02-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no function 'ftrace_ops_recurs_func' existing in the current code, it was renamed to ftrace_ops_assist_func() in commit c68c0fa29341 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too"). Update the comment to the correct function name. Link: http://lkml.kernel.org/r/1487723366-14463-1-git-send-email-chuhu@redhat.com Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | sched/headers: Prepare to use <linux/rcuupdate.h> instead of ↵Ingo Molnar2017-03-024-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/rculist.h> in <linux/sched.h> We don't actually need the full rculist.h header in sched.h anymore, we will be able to include the smaller rcupdate.h header instead. But first update code that relied on the implicit header inclusion. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>