From 2bc983b78c215765979a29a2e98b0cc01791c2d1 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 23 Apr 2016 06:05:01 -0700 Subject: Reduce number of mmap calls from __libc_memalign in ld.so __libc_memalign in ld.so allocates one page at a time and tries to optimize consecutive __libc_memalign calls by hoping that the next mmap is after the current memory allocation. However, the kernel hands out mmap addresses in top-down order, so this optimization in practice never happens, with the result that we have more mmap calls and waste a bunch of space for each __libc_memalign. This change makes __libc_memalign to mmap one page extra. Worst case, the kernel never puts a backing page behind it, but best case it allows __libc_memalign to operate much much better. For elf/tst-align --direct, it reduces number of mmap calls from 12 to 9. * elf/dl-minimal.c (__libc_memalign): Mmap one extra page. --- ChangeLog | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'ChangeLog') diff --git a/ChangeLog b/ChangeLog index 5cd8c4012b..744c0c0fb7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,7 @@ +2016-04-23 H.J. Lu + + * elf/dl-minimal.c (__libc_memalign): Mmap one extra page. + 2016-04-23 Mike Frysinger * locale/programs/ld-time.c (time_finish): Set week_1stweek to 7 -- cgit 1.4.1