From 114276ac0a3beb9c391a410349bd770653e185ce Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 26 May 2013 17:32:13 +0300 Subject: mm, sched: Drop voluntary schedule from might_fault() might_fault() is called from functions like copy_to_user() which most callers expect to be very fast, like a couple of instructions. So functions like memcpy_toiovec() call them many times in a loop. But might_fault() calls might_sleep() and with CONFIG_PREEMPT_VOLUNTARY this results in a function call. Let's not do this - just call __might_sleep() that produces a diagnostic for sleep within atomic, but drop might_preempt(). Here's a test sending traffic between the VM and the host, host is built with CONFIG_PREEMPT_VOLUNTARY: before: incoming: 7122.77 Mb/s outgoing: 8480.37 Mb/s after: incoming: 8619.24 Mb/s outgoing: 9455.42 Mb/s As a side effect, this fixes an issue pointed out by Ingo: might_fault might schedule differently depending on PROVE_LOCKING. Now there's no preemption point in both cases, so it's consistent. Signed-off-by: Michael S. Tsirkin Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1369577426-26721-10-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar --- include/linux/kernel.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e9ef6d6b51d5..24719eaa1209 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -198,7 +198,7 @@ void might_fault(void); #else static inline void might_fault(void) { - might_sleep(); + __might_sleep(__FILE__, __LINE__, 0); } #endif -- cgit v1.2.3 From 662bbcb2747c2422cf98d3d97619509379eee466 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 26 May 2013 17:32:23 +0300 Subject: mm, sched: Allow uaccess in atomic with pagefault_disable() This changes might_fault() so that it does not trigger a false positive diagnostic for e.g. the following sequence: spin_lock_irqsave() pagefault_disable() copy_to_user() pagefault_enable() spin_unlock_irqrestore() In particular vhost wants to do this, to call socket ops from under a lock. There are 3 cases to consider: - CONFIG_PROVE_LOCKING - might_fault is non-inline so it's easy to move the in_atomic test to fix up the false positive warning. - CONFIG_DEBUG_ATOMIC_SLEEP - might_fault is currently inline, but we are calling a non-inline __might_sleep anyway, so let's use the non-line version of might_fault that does the right thing. - !CONFIG_DEBUG_ATOMIC_SLEEP && !CONFIG_PROVE_LOCKING __might_sleep is a nop so might_fault is a nop. Make this explicit. Signed-off-by: Michael S. Tsirkin Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1369577426-26721-11-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar --- include/linux/kernel.h | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 24719eaa1209..4c7e2e508766 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -193,13 +193,10 @@ extern int _cond_resched(void); (__x < 0) ? -__x : __x; \ }) -#ifdef CONFIG_PROVE_LOCKING +#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) void might_fault(void); #else -static inline void might_fault(void) -{ - __might_sleep(__FILE__, __LINE__, 0); -} +static inline void might_fault(void) { } #endif extern struct atomic_notifier_head panic_notifier_list; -- cgit v1.2.3 From bcf312cf762f3ff02c0cbd218564e6241f0d1f9f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 2 May 2013 11:26:13 -0400 Subject: tracing: Put trace_puts() comment above trace_puts() macro for kernel doc Kernel-doc gives the following warning: DOCPROC Documentation/DocBook/kernel-api.xml Warning(/include/linux/kernel.h:590): No description found for parameter 'ip' Warning(/include/linux/kernel.h:590): No description found for parameter 'ip' Due to the externs between the the comment and the trace_puts() macro. This is fixed by moving the externs below the macro and keeping the macro and comment directly together. Reported-by: Robert P. J. Day Signed-off-by: Steven Rostedt Signed-off-by: Jiri Kosina --- include/linux/kernel.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e9ef6d6b51d5..bd95d1face2f 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -562,9 +562,6 @@ int __trace_bprintk(unsigned long ip, const char *fmt, ...); extern __printf(2, 3) int __trace_printk(unsigned long ip, const char *fmt, ...); -extern int __trace_bputs(unsigned long ip, const char *str); -extern int __trace_puts(unsigned long ip, const char *str, int size); - /** * trace_puts - write a string into the ftrace buffer * @str: the string to record @@ -600,6 +597,8 @@ extern int __trace_puts(unsigned long ip, const char *str, int size); else \ __trace_puts(_THIS_IP_, str, strlen(str)); \ }) +extern int __trace_bputs(unsigned long ip, const char *str); +extern int __trace_puts(unsigned long ip, const char *str, int size); extern void trace_dump_stack(int skip); -- cgit v1.2.3 From 4cd5773a2ae6facdde3f563087a4cc50f00d9530 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 4 Jun 2013 19:46:26 +0300 Subject: net: core: move mac_pton() to lib/net_utils.c Since we have at least one user of this function outside of CONFIG_NET scope, we have to provide this function independently. The proposed solution is to move it under lib/net_utils.c with corresponding configuration variable and select wherever it is needed. Signed-off-by: Andy Shevchenko Reported-by: Arnd Bergmann Acked-by: David S. Miller Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- include/linux/kernel.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e9ef6d6b51d5..3afb969441d1 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -450,6 +450,8 @@ static inline char * __deprecated pack_hex_byte(char *buf, u8 byte) extern int hex_to_bin(char ch); extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); +int mac_pton(const char *s, u8 *mac); + /* * General tracing related utility functions - trace_printk(), * tracing_on/tracing_off and tracing_start()/tracing_stop -- cgit v1.2.3 From e67bc51e574ffe3c4bc1e09cab7658b1e780b4ce Mon Sep 17 00:00:00 2001 From: Dhaval Giani Date: Fri, 2 Aug 2013 14:47:29 -0400 Subject: tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set When CONFIG_TRACING is not enabled, the stub prototype for trace_dump_stack() is incorrect. It has (void) when it should be (int). Link: http://lkml.kernel.org/r/CAPhKKr_H=ukFnBL4WgDOVT5ay2xeF-Ho+CA0DWZX0E2JW-=vSQ@mail.gmail.com Signed-off-by: Dhaval Giani Signed-off-by: Steven Rostedt --- include/linux/kernel.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3bef14c6586b..482ad2d84a32 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -629,7 +629,7 @@ extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); static inline void tracing_start(void) { } static inline void tracing_stop(void) { } static inline void ftrace_off_permanent(void) { } -static inline void trace_dump_stack(void) { } +static inline void trace_dump_stack(int skip) { } static inline void tracing_on(void) { } static inline void tracing_off(void) { } -- cgit v1.2.3