gecko-dev/memory/jemalloc/0006-Make-opt.lg_dirty_mult-work-as-documented.patch

48 lines
1.6 KiB
Diff

From 6505733012458d8fcd0ae8e1f1acdc9ffe33ff35 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh@glandium.org>
Date: Wed, 4 Feb 2015 07:16:55 +0900
Subject: [PATCH] Make opt.lg_dirty_mult work as documented
The documentation for opt.lg_dirty_mult says:
Per-arena minimum ratio (log base 2) of active to dirty
pages. Some dirty unused pages may be allowed to accumulate,
within the limit set by the ratio (or one chunk worth of dirty
pages, whichever is greater) (...)
The restriction in parentheses currently doesn't happen. This makes
jemalloc aggressively madvise(), which in turns increases the amount
of page faults significantly.
For instance, this resulted in several(!) hundred(!) milliseconds
startup regression on Firefox for Android.
This may require further tweaking, but starting with actually doing
what the documentation says is a good start.
---
src/arena.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/src/arena.c b/src/arena.c
index 984b8ad..a5033bf 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -850,6 +850,7 @@ arena_maybe_purge(arena_t *arena)
if (opt_lg_dirty_mult < 0)
return;
threshold = (arena->nactive >> opt_lg_dirty_mult);
+ threshold = threshold < chunk_npages ? chunk_npages : threshold;
/*
* Don't purge unless the number of purgeable pages exceeds the
* threshold.
@@ -893,6 +894,7 @@ arena_compute_npurge(arena_t *arena, bool all)
*/
if (!all) {
size_t threshold = (arena->nactive >> opt_lg_dirty_mult);
+ threshold = threshold < chunk_npages ? chunk_npages : threshold;
npurge = arena->ndirty - threshold;
} else
--
2.3.0.3.g98027e3