| Message ID | 20160920083615.31099-2-zajec5@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, 20 Sep 2016 10:36:15 +0200 Rafał Miłecki <zajec5@gmail.com> wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > Right now wbuf timer has hardcoded timeouts and there is no place for > manual adjustments. Some projects / cases many need that though. Few > file systems allow doing that by respecting dirty_writeback_interval > that can be set using sysctl (dirty_writeback_centisecs). > > Lowering dirty_writeback_interval could be some way of dealing with user > space apps lacking proper fsyncs. This is definitely *not* a perfect > solution but we don't have ideal (user space) world. There were already > advanced discussions on this matter, mostly when ext4 was introduced and > it wasn't behaving as ext3. Anyway, the final decision was to add some > hacks to the ext4, as trying to fix whole user space or adding new API > was pointless. > > We can't (and shouldn't?) just follow ext4. We can't e.g. sync on close > as this would cause too many commits and flash wearing. On the other > hand we still should allow some trade-off between -o sync and default > wbuf timeout. Respecting dirty_writeback_interval should allow some sane > cutomizations if used warily. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > V2: Fix delta calculation and make it more clear. Thanks Boris. > --- > fs/ubifs/io.c | 8 ++++---- > fs/ubifs/ubifs.h | 4 ---- > 2 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c > index 4d6ce4a..3be2890 100644 > --- a/fs/ubifs/io.c > +++ b/fs/ubifs/io.c > @@ -452,11 +452,11 @@ static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) > */ > static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) > { > - ktime_t softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); > - unsigned long long delta; > + ktime_t softlimit = ms_to_ktime(dirty_writeback_interval * 10); > + unsigned long long delta = dirty_writeback_interval; > > - delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > - delta *= 1000000000ULL; > + /* centi to milli, milli to nano, then 10% */ > + delta *= 10ULL * NSEC_PER_MSEC / 10ULL; > > ubifs_assert(!hrtimer_active(&wbuf->timer)); > ubifs_assert(delta <= ULONG_MAX); > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index 11bc8fa..26e6340 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -83,10 +83,6 @@ > */ > #define BGT_NAME_PATTERN "ubifs_bgt%d_%d" > > -/* Write-buffer synchronization timeout interval in seconds */ > -#define WBUF_TIMEOUT_SOFTLIMIT 3 > -#define WBUF_TIMEOUT_HARDLIMIT 5 > - > /* Maximum possible inode number (only 32-bit inodes are supported now) */ > #define MAX_INUM 0xFFFFFFFF >
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c index 4d6ce4a..3be2890 100644 --- a/fs/ubifs/io.c +++ b/fs/ubifs/io.c @@ -452,11 +452,11 @@ static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) */ static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) { - ktime_t softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); - unsigned long long delta; + ktime_t softlimit = ms_to_ktime(dirty_writeback_interval * 10); + unsigned long long delta = dirty_writeback_interval; - delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; - delta *= 1000000000ULL; + /* centi to milli, milli to nano, then 10% */ + delta *= 10ULL * NSEC_PER_MSEC / 10ULL; ubifs_assert(!hrtimer_active(&wbuf->timer)); ubifs_assert(delta <= ULONG_MAX); diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 11bc8fa..26e6340 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -83,10 +83,6 @@ */ #define BGT_NAME_PATTERN "ubifs_bgt%d_%d" -/* Write-buffer synchronization timeout interval in seconds */ -#define WBUF_TIMEOUT_SOFTLIMIT 3 -#define WBUF_TIMEOUT_HARDLIMIT 5 - /* Maximum possible inode number (only 32-bit inodes are supported now) */ #define MAX_INUM 0xFFFFFFFF