From 0b335b9d7d5f0b832e90ac469480789c07be80ad Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Tue, 23 Jun 2009 12:30:43 +0300 Subject: [PATCH] UBIFS: slightly optimize write-buffer timer usage This patch adds the following minor optimization: 1. If write-buffer does not use the timer, indicate it with the wbuf->no_timer variable, instead of using the wbuf->softlimit variable. This is better because wbuf->softlimit is of ktime_t type, and the ktime_to_ns function contains 64-bit multiplication. 2. Do not call the 'hrtimer_cancel()' function for write-buffers which do not use timers. 3. Do not cancel the timer in 'ubifs_put_super()' because the synchronization function does this. This patch also removes a confusing comment. Signed-off-by: Artem Bityutskiy --- fs/ubifs/io.c | 9 +++------ fs/ubifs/super.c | 6 ++---- fs/ubifs/ubifs.h | 6 ++++-- 3 files changed, 9 insertions(+), 12 deletions(-) diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c index 2ef689a9a363..9fcf6c38c1bc 100644 --- a/fs/ubifs/io.c +++ b/fs/ubifs/io.c @@ -312,7 +312,7 @@ static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) { ubifs_assert(!hrtimer_active(&wbuf->timer)); - if (!ktime_to_ns(wbuf->softlimit)) + if (wbuf->no_timer) return; dbg_io("set timer for jhead %d, %llu-%llu millisecs", wbuf->jhead, ktime_to_ns(wbuf->softlimit)/USEC_PER_SEC, @@ -327,11 +327,8 @@ static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) */ static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) { - /* - * If the syncer is waiting for the lock (from the background thread's - * context) and another task is changing write-buffer then the syncing - * should be canceled. - */ + if (wbuf->no_timer) + return; wbuf->need_sync = 0; hrtimer_cancel(&wbuf->timer); } diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 79fad43f3c57..5bb272c56a9b 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -797,7 +797,7 @@ static int alloc_wbufs(struct ubifs_info *c) * does not need to be synchronized by timer. */ c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM; - c->jheads[GCHD].wbuf.softlimit = ktime_set(0, 0); + c->jheads[GCHD].wbuf.no_timer = 1; return 0; } @@ -1754,10 +1754,8 @@ static void ubifs_put_super(struct super_block *sb) /* Synchronize write-buffers */ if (c->jheads) - for (i = 0; i < c->jhead_cnt; i++) { + for (i = 0; i < c->jhead_cnt; i++) ubifs_wbuf_sync(&c->jheads[i].wbuf); - hrtimer_cancel(&c->jheads[i].wbuf.timer); - } /* * On fatal errors c->ro_media is set to 1, in which case we do diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 1bf01d820066..97bc9d09d54b 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -654,7 +654,8 @@ typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, * @delta: hard and soft timeouts delta (the timer expire inteval is @softlimit * and @softlimit + @delta) * @timer: write-buffer timer - * @need_sync: it is set if its timer expired and needs sync + * @no_timer: non-zero if this write-buffer does not timer + * @need_sync: non-zero if its timer expired and needs sync * @next_ino: points to the next position of the following inode number * @inodes: stores the inode numbers of the nodes which are in wbuf * @@ -683,7 +684,8 @@ struct ubifs_wbuf { ktime_t softlimit; unsigned long long delta; struct hrtimer timer; - int need_sync; + unsigned int no_timer:1; + unsigned int need_sync:1; int next_ino; ino_t *inodes; }; -- 2.39.5