mm: don't set __GFP_WRITE on ramfs/sysfs writes

PATCH In review Fengguang Wu 2 participants 2 messages Mar 2, 2012 – Mar 4, 2012

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Memory management Page cache

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Fengguang Wu

author

2012-03-02 06:10 UTC #0 lore raw

PATCH 1/1 mm: don't set __GFP_WRITE on ramfs/sysfs writes

There is not much of a point in skipping zones during allocation based on the dirty usage which they'll never contribute to. And we'd like to avoid page reclaim waits when writing to ramfs/sysfs etc.

Acked-by Johannes Weiner <[email protected]>

Signed-off-by Fengguang Wu <[email protected]>

---
 mm/filemap.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

mm/filemap.c +3 -1

@@ -2341,7 +2341,9 @@ struct page *grab_cache_page_write_begin
 	struct page *page;
 	gfp_t gfp_notmask = 0;
 
-	gfp_mask = mapping_gfp_mask(mapping) | __GFP_WRITE;
+	gfp_mask = mapping_gfp_mask(mapping);
+	if (mapping_cap_account_dirty(mapping))
+		gfp_mask |= __GFP_WRITE;
 	if (flags & AOP_FLAG_NOFS)
 		gfp_notmask = __GFP_FS;
 repeat:

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Minchan Kim

Acked-by on v1 1/1

2012-03-04 07:11 UTC #1 lore raw

Quoted 6 lines · Fengguang Wu

There is not much of a point in skipping zones during allocation based on the dirty usage which they'll never contribute to. And we'd like to avoid page reclaim waits when writing to ramfs/sysfs etc.
Acked-by Johannes Weiner <[email protected]>
Signed-off-by Fengguang Wu <[email protected]>

Acked-by Minchan Kim <[email protected]>