From 5800dc3cff87c3a1548382298bb16e1fb4ec7e32 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Mon, 25 Nov 2013 23:23:04 +0000 Subject: panic: Make panic_timeout configurable The panic_timeout value can be set via the command line option 'panic=x', or via /proc/sys/kernel/panic, however that is not sufficient when the panic occurs before we are able to set up these values. Thus, add a CONFIG_PANIC_TIMEOUT so that we can set the desired value from the .config. The default panic_timeout value continues to be 0 - wait forever. Also adds set_arch_panic_timeout(new_timeout, arch_default_timeout), which is intended to be used by arches in arch_setup(). The idea being that the new_timeout is only set if the user hasn't changed from the arch_default_timeout. Signed-off-by: Jason Baron Cc: benh@kernel.crashing.org Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: mpe@ellerman.id.au Cc: felipe.contreras@gmail.com Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1a1674daec27c534df409697025ac568ebcee91e.1385418410.git.jbaron@akamai.com Signed-off-by: Ingo Molnar --- include/linux/kernel.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d4e98d13eff4..2ac02772a86e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -393,6 +393,15 @@ extern int panic_on_oops; extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; extern int sysctl_panic_on_stackoverflow; +/* + * Only to be used by arch init code. If the user over-wrote the default + * CONFIG_PANIC_TIMEOUT, honor it. + */ +static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) +{ + if (panic_timeout == arch_default_timeout) + panic_timeout = timeout; +} extern const char *print_tainted(void); enum lockdep_ok { LOCKDEP_STILL_OK, -- cgit v1.2.3-71-gd317 From 89770b0a69ee0e0e5e99c722192d535115f73778 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 22 Jan 2014 02:29:40 +0100 Subject: net: introduce reciprocal_scale helper and convert users As David Laight suggests, we shouldn't necessarily call this reciprocal_divide() when users didn't requested a reciprocal_value(); lets keep the basic idea and call it reciprocal_scale(). More background information on this topic can be found in [1]. Joint work with Hannes Frederic Sowa. [1] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html Suggested-by: David Laight Cc: Jakub Zawadzki Cc: Eric Dumazet Cc: linux-kernel@vger.kernel.org Signed-off-by: Hannes Frederic Sowa Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/kernel.h | 19 +++++++++++++++++++ include/net/codel.h | 4 +--- net/packet/af_packet.c | 3 +-- 3 files changed, 21 insertions(+), 5 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index ecb87544cc5d..03d8a6b0e2e8 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -193,6 +193,25 @@ extern int _cond_resched(void); (__x < 0) ? -__x : __x; \ }) +/** + * reciprocal_scale - "scale" a value into range [0, ep_ro) + * @val: value + * @ep_ro: right open interval endpoint + * + * Perform a "reciprocal multiplication" in order to "scale" a value into + * range [0, ep_ro), where the upper interval endpoint is right-open. + * This is useful, e.g. for accessing a index of an array containing + * ep_ro elements, for example. Think of it as sort of modulus, only that + * the result isn't that of modulo. ;) Note that if initial input is a + * small value, then result will return 0. + * + * Return: a result based on val in interval [0, ep_ro). + */ +static inline u32 reciprocal_scale(u32 val, u32 ep_ro) +{ + return (u32)(((u64) val * ep_ro) >> 32); +} + #if defined(CONFIG_MMU) && \ (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) void might_fault(void); diff --git a/include/net/codel.h b/include/net/codel.h index 3b04ff5f6f8d..fe0eab32ce76 100644 --- a/include/net/codel.h +++ b/include/net/codel.h @@ -46,7 +46,6 @@ #include #include #include -#include /* Controlling Queue Delay (CoDel) algorithm * ========================================= @@ -211,10 +210,9 @@ static codel_time_t codel_control_law(codel_time_t t, codel_time_t interval, u32 rec_inv_sqrt) { - return t + reciprocal_divide(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT); + return t + reciprocal_scale(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT); } - static bool codel_should_drop(const struct sk_buff *skb, struct Qdisc *sch, struct codel_vars *vars, diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index df3cbdd585c7..97346162803d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -88,7 +88,6 @@ #include #include #include -#include #include #ifdef CONFIG_INET #include @@ -1262,7 +1261,7 @@ static unsigned int fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num) { - return reciprocal_divide(skb->rxhash, num); + return reciprocal_scale(skb->rxhash, num); } static unsigned int fanout_demux_lb(struct packet_fanout *f, -- cgit v1.2.3-71-gd317 From 89a0714106aac7309c7dfa0f004b39e1e89d2942 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 23 Jan 2014 15:54:00 -0800 Subject: kernel.h: define u8, s8, u32, etc. limits Create constants that define the maximum and minimum values representable by the kernel types u8, s8, u16, s16, and so on. Signed-off-by: Alex Elder Cc: Sage Weil Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2aa3d4b000e6..f74bb581ab64 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -29,6 +29,19 @@ #define ULLONG_MAX (~0ULL) #define SIZE_MAX (~(size_t)0) +#define U8_MAX ((u8)~0U) +#define S8_MAX ((s8)(U8_MAX>>1)) +#define S8_MIN ((s8)(-S8_MAX - 1)) +#define U16_MAX ((u16)~0U) +#define S16_MAX ((s16)(U16_MAX>>1)) +#define S16_MIN ((s16)(-S16_MAX - 1)) +#define U32_MAX ((u32)~0U) +#define S32_MAX ((s32)(U32_MAX>>1)) +#define S32_MIN ((s32)(-S32_MAX - 1)) +#define U64_MAX ((u64)~0ULL) +#define S64_MAX ((s64)(U64_MAX>>1)) +#define S64_MIN ((s64)(-S64_MAX - 1)) + #define STACK_MAGIC 0xdeadbeef #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) -- cgit v1.2.3-71-gd317