[tip:perf/core] perf_events: Report the MMAP pgoff value in bytes

tip-bot for Peter Zijlstra
2010-02-26T10:25:44Z

Commit-ID: 3a0304e90aa5a2c0c308a05d28f7d109a48d8539
Gitweb: http://git.kernel.org/tip/3a0304e90aa5a2c0c308a05d28f7d109a48d8539
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 26 Feb 2010 10:33:41 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 26 Feb 2010 10:56:52 +0100

perf_events: Report the MMAP pgoff value in bytes

DaveM reported that currently perf interprets the pgoff value reported by
the MMAP events as a byte range, but the kernel reports it as a page
offset.

Since its broken (and unusable) anyway, change the kernel behaviour (ABI)
to report bytes indeed, avoiding the need for userspace to deal with
PAGE_SIZE things.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/perf_event.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 087025f..5a69abb 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3749,7 +3749,7 @@ void __perf_event_mmap(struct vm_area_struct *vma)
/* .tid */
.start = vma->vm_start,
.len = vma->vm_end - vma->vm_start,
- .pgoff = vma->vm_pgoff,
+ .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
},
};