From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri, 26 Feb 2010 09:33:41 +0000 (+0100)
Subject: perf_events: Report the MMAP pgoff value in bytes
X-Git-Tag: v2.6.34-rc1~262^2~9
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3a0304e90aa5a2c0c308a05d28f7d109a48d8539;p=linux-2.6-block.git

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>
---

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 087025fe3ba1..5a69abb05ac3 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,
 		},
 	};