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author | glebius <glebius@FreeBSD.org> | 2013-04-08 19:40:53 +0000 |
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committer | glebius <glebius@FreeBSD.org> | 2013-04-08 19:40:53 +0000 |
commit | 9cf64d6c35c62c34531273aadc2bfc0e0606fd77 (patch) | |
tree | de8f9f44d18df863668a203bd7eaeaea76185b92 /sys/i386 | |
parent | e01107c5d37d344c4a3ed663347b49eaf4527e4a (diff) | |
download | FreeBSD-src-9cf64d6c35c62c34531273aadc2bfc0e0606fd77.zip FreeBSD-src-9cf64d6c35c62c34531273aadc2bfc0e0606fd77.tar.gz |
Merge from projects/counters: counter(9).
Introduce counter(9) API, that implements fast and raceless counters,
provided (but not limited to) for gathering of statistical data.
See http://lists.freebsd.org/pipermail/freebsd-arch/2013-April/014204.html
for more details.
In collaboration with: kib
Reviewed by: luigi
Tested by: ae, ray
Sponsored by: Nginx, Inc.
Diffstat (limited to 'sys/i386')
-rw-r--r-- | sys/i386/include/counter.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/sys/i386/include/counter.h b/sys/i386/include/counter.h new file mode 100644 index 0000000..f45d953 --- /dev/null +++ b/sys/i386/include/counter.h @@ -0,0 +1,89 @@ +/*- + * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef __MACHINE_COUNTER_H__ +#define __MACHINE_COUNTER_H__ + +#include <sys/pcpu.h> +#ifdef INVARIANTS +#include <sys/proc.h> +#endif +#include <machine/md_var.h> +#include <machine/specialreg.h> + +#define counter_enter() do { \ + if ((cpu_feature & CPUID_CX8) == 0) \ + critical_enter(); \ +} while (0) + +#define counter_exit() do { \ + if ((cpu_feature & CPUID_CX8) == 0) \ + critical_exit(); \ +} while (0) + +static inline void +counter_64_inc_8b(uint64_t *p, int64_t inc) +{ + + __asm __volatile( + "movl %%fs:(%%esi),%%eax\n\t" + "movl %%fs:4(%%esi),%%edx\n" +"1:\n\t" + "movl %%eax,%%ebx\n\t" + "movl %%edx,%%ecx\n\t" + "addl (%%edi),%%ebx\n\t" + "adcl 4(%%edi),%%ecx\n\t" + "cmpxchg8b %%fs:(%%esi)\n\t" + "jnz 1b" + : + : "S" (p), "D" (&inc) + : "memory", "cc", "eax", "edx", "ebx", "ecx"); +} + +#define counter_u64_add_protected(c, inc) do { \ + if ((cpu_feature & CPUID_CX8) == 0) { \ + CRITICAL_ASSERT(curthread); \ + *(uint64_t *)zpcpu_get(c) += (inc); \ + } else \ + counter_64_inc_8b((c), (inc)); \ +} while (0) + +static inline void +counter_u64_add(counter_u64_t c, int64_t inc) +{ + + if ((cpu_feature & CPUID_CX8) == 0) { + critical_enter(); + *(uint64_t *)zpcpu_get(c) += inc; + critical_exit(); + } else { + counter_64_inc_8b(c, inc); + } +} + +#endif /* ! __MACHINE_COUNTER_H__ */ |