| Message ID | 20160914102435.22312-2-zajec5@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Wed, 14 Sep 2016 12:24:34 +0200 Rafał Miłecki <zajec5@gmail.com> wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > Values of these fields are set during init and never modified. They are > used (read) in a single function only. There isn't really any reason to > keep them in a struct. It only makes struct just a bit bigger without > any clear gain. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- > fs/ubifs/io.c | 18 ++++++++++-------- > fs/ubifs/ubifs.h | 5 ----- > 2 files changed, 10 insertions(+), 13 deletions(-) > > diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c > index 97be412..4d6ce4a 100644 > --- a/fs/ubifs/io.c > +++ b/fs/ubifs/io.c > @@ -452,16 +452,22 @@ 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; > + > + delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > + delta *= 1000000000ULL; > + > ubifs_assert(!hrtimer_active(&wbuf->timer)); > + ubifs_assert(delta <= ULONG_MAX); Hm, do we really want to recalculate delta each time we reschedule the wbuf timer? How about making the softlimit and delta variables static and initializing them once? > > if (wbuf->no_timer) > return; > dbg_io("set timer for jhead %s, %llu-%llu millisecs", > dbg_jhead(wbuf->jhead), > - div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), > - div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, > - USEC_PER_SEC)); > - hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, > + div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), > + div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); > + hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, > HRTIMER_MODE_REL); > } > > @@ -1059,10 +1065,6 @@ int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) > > hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > wbuf->timer.function = wbuf_timer_callback_nolock; > - wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); > - wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > - wbuf->delta *= 1000000000ULL; > - ubifs_assert(wbuf->delta <= ULONG_MAX); > return 0; > } > > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index 4617d45..11bc8fa 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -644,9 +644,6 @@ typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, > * @io_mutex: serializes write-buffer I/O > * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes > * fields > - * @softlimit: soft write-buffer timeout interval > - * @delta: hard and soft timeouts delta (the timer expire interval is @softlimit > - * and @softlimit + @delta) > * @timer: write-buffer timer > * @no_timer: non-zero if this write-buffer does not have a timer > * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing > @@ -675,8 +672,6 @@ struct ubifs_wbuf { > int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad); > struct mutex io_mutex; > spinlock_t lock; > - ktime_t softlimit; > - unsigned long long delta; > struct hrtimer timer; > unsigned int no_timer:1; > unsigned int need_sync:1;
On Wed, 14 Sep 2016 17:24:28 +0200 Boris Brezillon <boris.brezillon@free-electrons.com> wrote: > On Wed, 14 Sep 2016 12:24:34 +0200 > Rafał Miłecki <zajec5@gmail.com> wrote: > > > From: Rafał Miłecki <rafal@milecki.pl> > > > > Values of these fields are set during init and never modified. They are > > used (read) in a single function only. There isn't really any reason to > > keep them in a struct. It only makes struct just a bit bigger without > > any clear gain. > > > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > > --- > > fs/ubifs/io.c | 18 ++++++++++-------- > > fs/ubifs/ubifs.h | 5 ----- > > 2 files changed, 10 insertions(+), 13 deletions(-) > > > > diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c > > index 97be412..4d6ce4a 100644 > > --- a/fs/ubifs/io.c > > +++ b/fs/ubifs/io.c > > @@ -452,16 +452,22 @@ 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; > > + > > + delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > > + delta *= 1000000000ULL; > > + > > ubifs_assert(!hrtimer_active(&wbuf->timer)); > > + ubifs_assert(delta <= ULONG_MAX); > > Hm, do we really want to recalculate delta each time we reschedule the > wbuf timer? > > How about making the softlimit and delta variables static and > initializing them once? Nevermind. I just read patch 2, and these delta and softlimit values have to be recalculated to account for dirty_writeback_interval changes. > > > > > if (wbuf->no_timer) > > return; > > dbg_io("set timer for jhead %s, %llu-%llu millisecs", > > dbg_jhead(wbuf->jhead), > > - div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), > > - div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, > > - USEC_PER_SEC)); > > - hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, > > + div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), > > + div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); > > + hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, > > HRTIMER_MODE_REL); > > } > > > > @@ -1059,10 +1065,6 @@ int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) > > > > hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > > wbuf->timer.function = wbuf_timer_callback_nolock; > > - wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); > > - wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > > - wbuf->delta *= 1000000000ULL; > > - ubifs_assert(wbuf->delta <= ULONG_MAX); > > return 0; > > } > > > > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > > index 4617d45..11bc8fa 100644 > > --- a/fs/ubifs/ubifs.h > > +++ b/fs/ubifs/ubifs.h > > @@ -644,9 +644,6 @@ typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, > > * @io_mutex: serializes write-buffer I/O > > * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes > > * fields > > - * @softlimit: soft write-buffer timeout interval > > - * @delta: hard and soft timeouts delta (the timer expire interval is @softlimit > > - * and @softlimit + @delta) > > * @timer: write-buffer timer > > * @no_timer: non-zero if this write-buffer does not have a timer > > * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing > > @@ -675,8 +672,6 @@ struct ubifs_wbuf { > > int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad); > > struct mutex io_mutex; > > spinlock_t lock; > > - ktime_t softlimit; > > - unsigned long long delta; > > struct hrtimer timer; > > unsigned int no_timer:1; > > unsigned int need_sync:1; > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
On Wed, 14 Sep 2016 12:24:34 +0200 Rafał Miłecki <zajec5@gmail.com> wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > Values of these fields are set during init and never modified. They are > used (read) in a single function only. There isn't really any reason to > keep them in a struct. It only makes struct just a bit bigger without > any clear gain. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > fs/ubifs/io.c | 18 ++++++++++-------- > fs/ubifs/ubifs.h | 5 ----- > 2 files changed, 10 insertions(+), 13 deletions(-) > > diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c > index 97be412..4d6ce4a 100644 > --- a/fs/ubifs/io.c > +++ b/fs/ubifs/io.c > @@ -452,16 +452,22 @@ 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; > + > + delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > + delta *= 1000000000ULL; > + > ubifs_assert(!hrtimer_active(&wbuf->timer)); > + ubifs_assert(delta <= ULONG_MAX); > > if (wbuf->no_timer) > return; > dbg_io("set timer for jhead %s, %llu-%llu millisecs", > dbg_jhead(wbuf->jhead), > - div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), > - div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, > - USEC_PER_SEC)); > - hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, > + div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), > + div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); > + hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, > HRTIMER_MODE_REL); > } > > @@ -1059,10 +1065,6 @@ int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) > > hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > wbuf->timer.function = wbuf_timer_callback_nolock; > - wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); > - wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; > - wbuf->delta *= 1000000000ULL; > - ubifs_assert(wbuf->delta <= ULONG_MAX); > return 0; > } > > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index 4617d45..11bc8fa 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -644,9 +644,6 @@ typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, > * @io_mutex: serializes write-buffer I/O > * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes > * fields > - * @softlimit: soft write-buffer timeout interval > - * @delta: hard and soft timeouts delta (the timer expire interval is @softlimit > - * and @softlimit + @delta) > * @timer: write-buffer timer > * @no_timer: non-zero if this write-buffer does not have a timer > * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing > @@ -675,8 +672,6 @@ struct ubifs_wbuf { > int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad); > struct mutex io_mutex; > spinlock_t lock; > - ktime_t softlimit; > - unsigned long long delta; > struct hrtimer timer; > unsigned int no_timer:1; > unsigned int need_sync:1;
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c index 97be412..4d6ce4a 100644 --- a/fs/ubifs/io.c +++ b/fs/ubifs/io.c @@ -452,16 +452,22 @@ 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; + + delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; + delta *= 1000000000ULL; + ubifs_assert(!hrtimer_active(&wbuf->timer)); + ubifs_assert(delta <= ULONG_MAX); if (wbuf->no_timer) return; dbg_io("set timer for jhead %s, %llu-%llu millisecs", dbg_jhead(wbuf->jhead), - div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), - div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, - USEC_PER_SEC)); - hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, + div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), + div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); + hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, HRTIMER_MODE_REL); } @@ -1059,10 +1065,6 @@ int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); wbuf->timer.function = wbuf_timer_callback_nolock; - wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); - wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; - wbuf->delta *= 1000000000ULL; - ubifs_assert(wbuf->delta <= ULONG_MAX); return 0; } diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 4617d45..11bc8fa 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -644,9 +644,6 @@ typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, * @io_mutex: serializes write-buffer I/O * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes * fields - * @softlimit: soft write-buffer timeout interval - * @delta: hard and soft timeouts delta (the timer expire interval is @softlimit - * and @softlimit + @delta) * @timer: write-buffer timer * @no_timer: non-zero if this write-buffer does not have a timer * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing @@ -675,8 +672,6 @@ struct ubifs_wbuf { int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad); struct mutex io_mutex; spinlock_t lock; - ktime_t softlimit; - unsigned long long delta; struct hrtimer timer; unsigned int no_timer:1; unsigned int need_sync:1;