From 4df9e19392b2aee80bbe12cd1e6f2fcb7fa3ae3c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 12 Jan 2012 17:19:43 -0800 Subject: mm: compaction: introduce sync-light migration for use by compaction commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 upstream. Stable note: Not tracked in Buzilla. This was part of a series that reduced interactivity stalls experienced when THP was enabled. These stalls were particularly noticable when copying data to a USB stick but the experiences for users varied a lot. This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- fs/nfs/internal.h | 2 +- fs/nfs/write.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 8d96ed6af6db..68b3f2041a11 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -330,7 +330,7 @@ void nfs_commit_release_pages(struct nfs_write_data *data); #ifdef CONFIG_MIGRATION extern int nfs_migrate_page(struct address_space *, - struct page *, struct page *, bool); + struct page *, struct page *, enum migrate_mode); #else #define nfs_migrate_page NULL #endif diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 31b246194f87..c6e523ad2687 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1711,7 +1711,7 @@ out_error: #ifdef CONFIG_MIGRATION int nfs_migrate_page(struct address_space *mapping, struct page *newpage, - struct page *page, bool sync) + struct page *page, enum migrate_mode mode) { /* * If PagePrivate is set, then the page is currently associated with @@ -1726,7 +1726,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage, nfs_fscache_release_page(page, GFP_KERNEL); - return migrate_page(mapping, newpage, page, sync); + return migrate_page(mapping, newpage, page, mode); } #endif -- cgit v1.2.3