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perf: Remove the extra validity check on nr_pages

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The function is_power_of_2() also do the check on nr_pages, so the first
check performed is unnecessary. On the other hand, the key point is to
ensure @nr_pages is a power-of-two number and mostly @nr_pages is a
nonzero value, so in the most cases, the function is_power_of_2() will
be called.

Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/1422352512-75150-1-git-send-email-xiakaixu@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Kaixu Xia 2015-01-27 17:55:12 +08:00 committed by Arnaldo Carvalho de Melo
parent 3a03005ff9
commit 74390aa556
1 changed files with 1 additions and 1 deletions
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kernel/events/core.c
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@ -4420,7 +4420,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
* If we have rb pages ensure they're a power-of-two number, so we
* can do bitmasks instead of modulo.
*/
if (nr_pages != 0 && !is_power_of_2(nr_pages))
if (!is_power_of_2(nr_pages))
return -EINVAL;
if (vma_size != PAGE_SIZE * (1 + nr_pages))