Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On 03/04/2015 08:37 AM, Tejun Heo wrote:
Subject: writeback: add missing INITIAL_JIFFIES init in
global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Fixes: c42843f2f0bb ("writeback: introduce smoothed global dirty limit")
Signed-off-by: Tejun Heo
Acked-by: Jan Kara
Cc: Wu Fengguang
Cc: Jens Axboe
Cc: sta...@vger.kernel.org
---
Added the "fixes" tag. Jens, can you please route this one?
Yup will do, thanks Tejun.
--
Jens Axboe
--
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[PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
Subject: writeback: add missing INITIAL_JIFFIES init in
global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Fixes: c42843f2f0bb ("writeback: introduce smoothed global dirty limit")
Signed-off-by: Tejun Heo
Acked-by: Jan Kara
Cc: Wu Fengguang
Cc: Jens Axboe
Cc: sta...@vger.kernel.org
---
Added the "fixes" tag. Jens, can you please route this one?
Thanks.
mm/page-writeback.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
unsigned long now)
{
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
/*
* check locklessly first to optimize away locking for the most time
--
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Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On 03/04/2015 08:30 AM, Jan Kara wrote: On Wed 04-03-15 10:22:43, Tejun Heo wrote: global_update_bandwidth() uses static variable update_time as the timestamp for the last update but forgets to initialize it to INITIALIZE_JIFFIES. This means that global_dirty_limit will be 5 mins into the future on 32bit and some large amount jiffies into the past on 64bit. This isn't critical as the only effect is that global_dirty_limit won't be updated for the first 5 mins after booting on 32bit machines, especially given the auxiliary nature of global_dirty_limit's role - protecting against global dirty threshold's sudden dips; however, it does lead to unintended suboptimal behavior. Fix it. Looks good. You can add: Reviewed-by: Jan Kara We should add that it fixes c42843f2f0bbc (from 2011!) as well. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On Wed 04-03-15 10:22:43, Tejun Heo wrote:
> global_update_bandwidth() uses static variable update_time as the
> timestamp for the last update but forgets to initialize it to
> INITIALIZE_JIFFIES.
>
> This means that global_dirty_limit will be 5 mins into the future on
> 32bit and some large amount jiffies into the past on 64bit. This
> isn't critical as the only effect is that global_dirty_limit won't be
> updated for the first 5 mins after booting on 32bit machines,
> especially given the auxiliary nature of global_dirty_limit's role -
> protecting against global dirty threshold's sudden dips; however, it
> does lead to unintended suboptimal behavior. Fix it.
Looks good. You can add:
Reviewed-by: Jan Kara
Honza
>
> Signed-off-by: Tejun Heo
> Cc: Wu Fengguang
> Cc: Jan Kara
> Cc: Jens Axboe
> Cc: sta...@vger.kernel.org
> ---
> mm/page-writeback.c |2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
> unsigned long now)
> {
> static DEFINE_SPINLOCK(dirty_lock);
> - static unsigned long update_time;
> + static unsigned long update_time = INITIAL_JIFFIES;
>
> /*
>* check locklessly first to optimize away locking for the most time
--
Jan Kara
SUSE Labs, CR
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Signed-off-by: Tejun Heo
Cc: Wu Fengguang
Cc: Jan Kara
Cc: Jens Axboe
Cc: sta...@vger.kernel.org
---
mm/page-writeback.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
unsigned long now)
{
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
/*
* check locklessly first to optimize away locking for the most time
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On Wed 04-03-15 10:22:43, Tejun Heo wrote:
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Looks good. You can add:
Reviewed-by: Jan Kara j...@suse.cz
Honza
Signed-off-by: Tejun Heo t...@kernel.org
Cc: Wu Fengguang fengguang...@intel.com
Cc: Jan Kara j...@suse.cz
Cc: Jens Axboe ax...@kernel.dk
Cc: sta...@vger.kernel.org
---
mm/page-writeback.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
unsigned long now)
{
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
/*
* check locklessly first to optimize away locking for the most time
--
Jan Kara j...@suse.cz
SUSE Labs, CR
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Signed-off-by: Tejun Heo t...@kernel.org
Cc: Wu Fengguang fengguang...@intel.com
Cc: Jan Kara j...@suse.cz
Cc: Jens Axboe ax...@kernel.dk
Cc: sta...@vger.kernel.org
---
mm/page-writeback.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
unsigned long now)
{
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
/*
* check locklessly first to optimize away locking for the most time
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
Subject: writeback: add missing INITIAL_JIFFIES init in
global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the
timestamp for the last update but forgets to initialize it to
INITIALIZE_JIFFIES.
This means that global_dirty_limit will be 5 mins into the future on
32bit and some large amount jiffies into the past on 64bit. This
isn't critical as the only effect is that global_dirty_limit won't be
updated for the first 5 mins after booting on 32bit machines,
especially given the auxiliary nature of global_dirty_limit's role -
protecting against global dirty threshold's sudden dips; however, it
does lead to unintended suboptimal behavior. Fix it.
Fixes: c42843f2f0bb (writeback: introduce smoothed global dirty limit)
Signed-off-by: Tejun Heo t...@kernel.org
Acked-by: Jan Kara j...@suse.cz
Cc: Wu Fengguang fengguang...@intel.com
Cc: Jens Axboe ax...@kernel.dk
Cc: sta...@vger.kernel.org
---
Added the fixes tag. Jens, can you please route this one?
Thanks.
mm/page-writeback.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsi
unsigned long now)
{
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
/*
* check locklessly first to optimize away locking for the most time
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On 03/04/2015 08:37 AM, Tejun Heo wrote: Subject: writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth() global_update_bandwidth() uses static variable update_time as the timestamp for the last update but forgets to initialize it to INITIALIZE_JIFFIES. This means that global_dirty_limit will be 5 mins into the future on 32bit and some large amount jiffies into the past on 64bit. This isn't critical as the only effect is that global_dirty_limit won't be updated for the first 5 mins after booting on 32bit machines, especially given the auxiliary nature of global_dirty_limit's role - protecting against global dirty threshold's sudden dips; however, it does lead to unintended suboptimal behavior. Fix it. Fixes: c42843f2f0bb (writeback: introduce smoothed global dirty limit) Signed-off-by: Tejun Heo t...@kernel.org Acked-by: Jan Kara j...@suse.cz Cc: Wu Fengguang fengguang...@intel.com Cc: Jens Axboe ax...@kernel.dk Cc: sta...@vger.kernel.org --- Added the fixes tag. Jens, can you please route this one? Yup will do, thanks Tejun. -- Jens Axboe -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH block/for-4.0-fixes] writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
On 03/04/2015 08:30 AM, Jan Kara wrote: On Wed 04-03-15 10:22:43, Tejun Heo wrote: global_update_bandwidth() uses static variable update_time as the timestamp for the last update but forgets to initialize it to INITIALIZE_JIFFIES. This means that global_dirty_limit will be 5 mins into the future on 32bit and some large amount jiffies into the past on 64bit. This isn't critical as the only effect is that global_dirty_limit won't be updated for the first 5 mins after booting on 32bit machines, especially given the auxiliary nature of global_dirty_limit's role - protecting against global dirty threshold's sudden dips; however, it does lead to unintended suboptimal behavior. Fix it. Looks good. You can add: Reviewed-by: Jan Kara j...@suse.cz We should add that it fixes c42843f2f0bbc (from 2011!) as well. -- Jens Axboe -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
