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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/amd64/include | |
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/amd64/include')
-rw-r--r-- | sys/amd64/include/counter.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/sys/amd64/include/counter.h b/sys/amd64/include/counter.h new file mode 100644 index 0000000..3ed5f76 --- /dev/null +++ b/sys/amd64/include/counter.h @@ -0,0 +1,51 @@ +/*- + * 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> + +extern struct pcpu __pcpu[1]; + +#define counter_enter() do {} while (0) +#define counter_exit() do {} while (0) + +#define counter_u64_add_protected(c, i) counter_u64_add(c, i) + +static inline void +counter_u64_add(counter_u64_t c, int64_t inc) +{ + + __asm __volatile("addq\t%1,%%gs:(%0)" + : + : "r" ((char *)c - (char *)&__pcpu[0]), "r" (inc) + : "memory", "cc"); +} + +#endif /* ! __MACHINE_COUNTER_H__ */ |