From: Miklos Szeredi Set the read and write congestion state if the request queue is close to blocking, and clear it when it's not. This prevents unnecessary blocking in readahead and (when writable mmaps are allowed) writeback. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton --- fs/fuse/dev.c | 8 ++++++++ fs/fuse/fuse_i.h | 5 ++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff -puN fs/fuse/dev.c~fuse-update-backing_dev_info-congestion-state fs/fuse/dev.c --- a/fs/fuse/dev.c~fuse-update-backing_dev_info-congestion-state +++ a/fs/fuse/dev.c @@ -224,6 +224,10 @@ static void request_end(struct fuse_conn fc->blocked = 0; wake_up_all(&fc->blocked_waitq); } + if (fc->num_background == FUSE_CONGESTION_THRESHOLD) { + clear_bdi_congested(&fc->bdi, READ); + clear_bdi_congested(&fc->bdi, WRITE); + } fc->num_background--; } spin_unlock(&fc->lock); @@ -378,6 +382,10 @@ static void request_send_nowait(struct f fc->num_background++; if (fc->num_background == FUSE_MAX_BACKGROUND) fc->blocked = 1; + if (fc->num_background == FUSE_CONGESTION_THRESHOLD) { + set_bdi_congested(&fc->bdi, READ); + set_bdi_congested(&fc->bdi, WRITE); + } queue_request(fc, req); spin_unlock(&fc->lock); diff -puN fs/fuse/fuse_i.h~fuse-update-backing_dev_info-congestion-state fs/fuse/fuse_i.h --- a/fs/fuse/fuse_i.h~fuse-update-backing_dev_info-congestion-state +++ a/fs/fuse/fuse_i.h @@ -20,7 +20,10 @@ #define FUSE_MAX_PAGES_PER_REQ 32 /** Maximum number of outstanding background requests */ -#define FUSE_MAX_BACKGROUND 10 +#define FUSE_MAX_BACKGROUND 12 + +/** Congestion starts at 75% of maximum */ +#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100) /** It could be as large as PATH_MAX, but would that have any uses? */ #define FUSE_NAME_MAX 1024 _