From 51a7380b8968251a49a4c5b0bc7ed1af5b0512c6 Mon Sep 17 00:00:00 2001 From: Will Newton Date: Fri, 13 Jun 2014 16:37:12 +0100 Subject: [PATCH] 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 * malloc/malloc.c (systrim): If extra is zero then return early. --- ChangeLog | 5 +++++ malloc/malloc.c | 3 +++ 2 files changed, 8 insertions(+) diff --git a/ChangeLog b/ChangeLog index 2a11522..ea0c48f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2014-06-19 Will Newton + + * malloc/malloc.c (systrim): If extra is zero then return + early. + 2014-06-19 Siddhesh Poyarekar * benchtests/Makefile ($(objpfx)bench-%.c): Remove $(.). diff --git a/malloc/malloc.c b/malloc/malloc.c index d8fd8b4..41fd76a 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -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. -- 2.7.4