malloc/malloc.c: Avoid calling sbrk unnecessarily with zero

Due to my bad review suggestion for the fix for BZ #15089 a check
was removed from systrim to prevent sbrk being called with a zero
argument. Add the check back to avoid this useless work.

ChangeLog:

2014-06-19  Will Newton  <will.newton@linaro.org>

	* malloc/malloc.c (systrim): If extra is zero then return
	early.
This commit is contained in:
Will Newton 2014-06-13 16:37:12 +01:00
parent 91b84fe588
commit 51a7380b89
2 changed files with 8 additions and 0 deletions

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@ -1,3 +1,8 @@
2014-06-19 Will Newton <will.newton@linaro.org>
* malloc/malloc.c (systrim): If extra is zero then return
early.
2014-06-19 Siddhesh Poyarekar <siddhesh@redhat.com>
* benchtests/Makefile ($(objpfx)bench-%.c): Remove $(.).

View File

@ -2749,6 +2749,9 @@ systrim (size_t pad, mstate av)
/* Release in pagesize units, keeping at least one page */
extra = (top_area - pad) & ~(pagesz - 1);
if (extra == 0)
return 0;
/*
Only proceed if end of memory is where we last set it.
This avoids problems if there were foreign sbrk calls.