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perf: Move mmap page data_head offset assertion out of header 

Having the build time assertion in header is making the perf
build fail on x86 with:

  ../../include/linux/perf_event.h:411:32: error: variably modified \
		‘__assert_mmap_data_head_offset’ at file scope [-Werror]

I'm moving the build time validation out of the header, because
I think it's better than to lessen the perf build warn/error
check.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: acme@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: cjashfor@linux.vnet.ibm.com
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/1332513680-7870-1-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Jiri Olsa 2012-03-23 15:41:20 +01:00 committed by Ingo Molnar
parent 04a54d27ce
commit b01c3a0010
2 changed files with 7 additions and 7 deletions
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7
include/linux/perf_event.h
View File

@ -403,13 +403,6 @@ struct perf_event_mmap_page {
__u64 data_tail; /* user-space written tail */
};
/*
* Build time assertion that we keep the data_head at the intended location.
* IOW, validation we got the __reserved[] size right.
*/
extern char __assert_mmap_data_head_offset
[1 - 2*!!(offsetof(struct perf_event_mmap_page, data_head) != 1024)];
#define PERF_RECORD_MISC_CPUMODE_MASK (7 << 0)
#define PERF_RECORD_MISC_CPUMODE_UNKNOWN (0 << 0)
#define PERF_RECORD_MISC_KERNEL (1 << 0)

7
kernel/events/core.c
View File

@ -7116,6 +7116,13 @@ void __init perf_event_init(void)
/* do not patch jump label more than once per second */
jump_label_rate_limit(&perf_sched_events, HZ);
/*
* Build time assertion that we keep the data_head at the intended
* location. IOW, validation we got the __reserved[] size right.
*/
BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
!= 1024);
}
static int __init perf_event_sysfs_init(void)