mm: Kconfig: Add support for config size of purging vmap_area
This size is the maximum amount of virtual address space we gather
up before attempting to purge with a TLB flush. It is 128M in most cases.
With repeated and high size vmalloc operations, it may easily generate
more fragments. This is wasting limited vmalloc area, for 32bits.
So make it configable and the default multiplier as 8, 32bits only.
Change-Id: I68a75acb16d3cff05f8b13c05ae78922269e219f
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ed89128..7b3865c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -657,7 +657,8 @@
log = fls(num_online_cpus());
- return log * (32UL * 1024 * 1024 / PAGE_SIZE);
+ return log * (1UL * CONFIG_VMAP_LAZY_PURGING_FACTOR *
+ 1024 * 1024 / PAGE_SIZE);
}
static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);