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tools/perf: Add required memory barriers
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To match patch bf378d3 ("perf: Fix perf ring buffer memory
ordering") change userspace to also adhere to the ordering outlined.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Link: http://lkml.kernel.org/r/20131030104246.GH16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored and Ingo Molnar committed Nov 6, 2013
1 parent 0a19684 commit a94d342
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Showing 3 changed files with 49 additions and 16 deletions.
59 changes: 47 additions & 12 deletions tools/perf/perf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
#include <asm/unistd.h>

#if defined(__i386__)
#define mb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
#define wmb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
#define rmb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
#define cpu_relax() asm volatile("rep; nop" ::: "memory");
#define CPUINFO_PROC "model name"
Expand All @@ -13,6 +15,8 @@
#endif

#if defined(__x86_64__)
#define mb() asm volatile("mfence" ::: "memory")
#define wmb() asm volatile("sfence" ::: "memory")
#define rmb() asm volatile("lfence" ::: "memory")
#define cpu_relax() asm volatile("rep; nop" ::: "memory");
#define CPUINFO_PROC "model name"
Expand All @@ -23,45 +27,61 @@

#ifdef __powerpc__
#include "../../arch/powerpc/include/uapi/asm/unistd.h"
#define mb() asm volatile ("sync" ::: "memory")
#define wmb() asm volatile ("sync" ::: "memory")
#define rmb() asm volatile ("sync" ::: "memory")
#define cpu_relax() asm volatile ("" ::: "memory");
#define CPUINFO_PROC "cpu"
#endif

#ifdef __s390__
#define mb() asm volatile("bcr 15,0" ::: "memory")
#define wmb() asm volatile("bcr 15,0" ::: "memory")
#define rmb() asm volatile("bcr 15,0" ::: "memory")
#define cpu_relax() asm volatile("" ::: "memory");
#endif

#ifdef __sh__
#if defined(__SH4A__) || defined(__SH5__)
# define mb() asm volatile("synco" ::: "memory")
# define wmb() asm volatile("synco" ::: "memory")
# define rmb() asm volatile("synco" ::: "memory")
#else
# define mb() asm volatile("" ::: "memory")
# define wmb() asm volatile("" ::: "memory")
# define rmb() asm volatile("" ::: "memory")
#endif
#define cpu_relax() asm volatile("" ::: "memory")
#define CPUINFO_PROC "cpu type"
#endif

#ifdef __hppa__
#define mb() asm volatile("" ::: "memory")
#define wmb() asm volatile("" ::: "memory")
#define rmb() asm volatile("" ::: "memory")
#define cpu_relax() asm volatile("" ::: "memory");
#define CPUINFO_PROC "cpu"
#endif

#ifdef __sparc__
#ifdef __LP64__
#define mb() asm volatile("ba,pt %%xcc, 1f\n" \
"membar #StoreLoad\n" \
"1:\n":::"memory")
#else
#define mb() asm volatile("":::"memory")
#endif
#define wmb() asm volatile("":::"memory")
#define rmb() asm volatile("":::"memory")
#define cpu_relax() asm volatile("":::"memory")
#define CPUINFO_PROC "cpu"
#endif

#ifdef __alpha__
#define mb() asm volatile("mb" ::: "memory")
#define wmb() asm volatile("wmb" ::: "memory")
#define rmb() asm volatile("mb" ::: "memory")
#define cpu_relax() asm volatile("" ::: "memory")
#define CPUINFO_PROC "cpu model"
#endif

#ifdef __ia64__
#define mb() asm volatile ("mf" ::: "memory")
#define wmb() asm volatile ("mf" ::: "memory")
#define rmb() asm volatile ("mf" ::: "memory")
#define cpu_relax() asm volatile ("hint @pause" ::: "memory")
#define CPUINFO_PROC "model name"
Expand All @@ -72,40 +92,55 @@
* Use the __kuser_memory_barrier helper in the CPU helper page. See
* arch/arm/kernel/entry-armv.S in the kernel source for details.
*/
#define mb() ((void(*)(void))0xffff0fa0)()
#define wmb() ((void(*)(void))0xffff0fa0)()
#define rmb() ((void(*)(void))0xffff0fa0)()
#define cpu_relax() asm volatile("":::"memory")
#define CPUINFO_PROC "Processor"
#endif

#ifdef __aarch64__
#define rmb() asm volatile("dmb ld" ::: "memory")
#define mb() asm volatile("dmb ish" ::: "memory")
#define wmb() asm volatile("dmb ishld" ::: "memory")
#define rmb() asm volatile("dmb ishst" ::: "memory")
#define cpu_relax() asm volatile("yield" ::: "memory")
#endif

#ifdef __mips__
#define rmb() asm volatile( \
#define mb() asm volatile( \
".set mips2\n\t" \
"sync\n\t" \
".set mips0" \
: /* no output */ \
: /* no input */ \
: "memory")
#define cpu_relax() asm volatile("" ::: "memory")
#define wmb() mb()
#define rmb() mb()
#define CPUINFO_PROC "cpu model"
#endif

#ifdef __arc__
#define mb() asm volatile("" ::: "memory")
#define wmb() asm volatile("" ::: "memory")
#define rmb() asm volatile("" ::: "memory")
#define cpu_relax() rmb()
#define CPUINFO_PROC "Processor"
#endif

#ifdef __metag__
#define mb() asm volatile("" ::: "memory")
#define wmb() asm volatile("" ::: "memory")
#define rmb() asm volatile("" ::: "memory")
#define cpu_relax() asm volatile("" ::: "memory")
#define CPUINFO_PROC "CPU"
#endif

#define barrier() asm volatile ("" ::: "memory")

#ifndef cpu_relax
#define cpu_relax() barrier()
#endif

#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))


#include <time.h>
#include <unistd.h>
#include <sys/types.h>
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2 changes: 0 additions & 2 deletions tools/perf/tests/rdpmc.c
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Expand Up @@ -9,8 +9,6 @@

#if defined(__x86_64__) || defined(__i386__)

#define barrier() asm volatile("" ::: "memory")

static u64 rdpmc(unsigned int counter)
{
unsigned int low, high;
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4 changes: 2 additions & 2 deletions tools/perf/util/evlist.h
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Expand Up @@ -177,7 +177,7 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist, int err, char *buf, s
static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm)
{
struct perf_event_mmap_page *pc = mm->base;
int head = pc->data_head;
int head = ACCESS_ONCE(pc->data_head);
rmb();
return head;
}
Expand All @@ -190,7 +190,7 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md,
/*
* ensure all reads are done before we write the tail out.
*/
/* mb(); */
mb();
pc->data_tail = tail;
}

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