Merge "mm: Kconfig: Add support for config size of purging vmap_area"

2 files changed, 12 insertions, 1 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index dcca76e498df..1105a5b79b1e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -601,6 +601,16 @@ config ZSMALLOC_STAT
 	  information to userspace via debugfs.
 	  If unsure, say N.
 
+config VMAP_LAZY_PURGING_FACTOR
+	int "multiplier to the size of purged vmap areas"
+	default "8" if ARM
+	default "32"
+	help
+	  It is used as a multiplier to the max VA pages purged in a
+	  single attempt. For 32-bit in order to reduce fragmentation
+	  of vmalloc space, we decrease the default value to "8".
+
+
 config GENERIC_EARLY_IOREMAP
 	bool
 
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index c3c28beaae11..ceb7d0d6db35 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -624,7 +624,8 @@ static unsigned long lazy_max_pages(void)
 
 	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);