Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Dave Chinner
On Mon, Aug 27, 2018 at 11:34:13AM -0400, Waiman Long wrote: > On 08/26/2018 08:21 PM, Dave Chinner wrote: > > On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: > >> The current log space reservation code allows multiple wakeups of the > >> same sleeping waiter to happen. This is a just

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Dave Chinner
On Mon, Aug 27, 2018 at 11:34:13AM -0400, Waiman Long wrote: > On 08/26/2018 08:21 PM, Dave Chinner wrote: > > On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: > >> The current log space reservation code allows multiple wakeups of the > >> same sleeping waiter to happen. This is a just

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Dave Chinner
On Mon, Aug 27, 2018 at 12:39:06AM -0700, Christoph Hellwig wrote: > On Mon, Aug 27, 2018 at 10:21:34AM +1000, Dave Chinner wrote: > > tl; dr: Once you pass a certain point, ramdisks can be *much* slower > > than SSDs on journal intensive workloads like AIM7. Hence it would be > > useful to see if

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Dave Chinner
On Mon, Aug 27, 2018 at 12:39:06AM -0700, Christoph Hellwig wrote: > On Mon, Aug 27, 2018 at 10:21:34AM +1000, Dave Chinner wrote: > > tl; dr: Once you pass a certain point, ramdisks can be *much* slower > > than SSDs on journal intensive workloads like AIM7. Hence it would be > > useful to see if

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Waiman Long
On 08/26/2018 08:21 PM, Dave Chinner wrote: > On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: >> The current log space reservation code allows multiple wakeups of the >> same sleeping waiter to happen. This is a just a waste of cpu time as >> well as increasing spin lock hold time. So

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Waiman Long
On 08/26/2018 08:21 PM, Dave Chinner wrote: > On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: >> The current log space reservation code allows multiple wakeups of the >> same sleeping waiter to happen. This is a just a waste of cpu time as >> well as increasing spin lock hold time. So

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Christoph Hellwig
On Mon, Aug 27, 2018 at 10:21:34AM +1000, Dave Chinner wrote: > tl; dr: Once you pass a certain point, ramdisks can be *much* slower > than SSDs on journal intensive workloads like AIM7. Hence it would be > useful to see if you have the same problems on, say, high > performance nvme SSDs. Note

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-27 Thread Christoph Hellwig
On Mon, Aug 27, 2018 at 10:21:34AM +1000, Dave Chinner wrote: > tl; dr: Once you pass a certain point, ramdisks can be *much* slower > than SSDs on journal intensive workloads like AIM7. Hence it would be > useful to see if you have the same problems on, say, high > performance nvme SSDs. Note

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-26 Thread Dave Chinner
On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: > The current log space reservation code allows multiple wakeups of the > same sleeping waiter to happen. This is a just a waste of cpu time as > well as increasing spin lock hold time. So a new XLOG_TIC_WAKING flag is > added to track

Re: [PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-26 Thread Dave Chinner
On Sun, Aug 26, 2018 at 04:53:14PM -0400, Waiman Long wrote: > The current log space reservation code allows multiple wakeups of the > same sleeping waiter to happen. This is a just a waste of cpu time as > well as increasing spin lock hold time. So a new XLOG_TIC_WAKING flag is > added to track

[PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-26 Thread Waiman Long
The current log space reservation code allows multiple wakeups of the same sleeping waiter to happen. This is a just a waste of cpu time as well as increasing spin lock hold time. So a new XLOG_TIC_WAKING flag is added to track if a task is being waken up and skip the wake_up_process() call if the

[PATCH v2 2/3] xfs: Prevent multiple wakeups of the same log space waiter

2018-08-26 Thread Waiman Long
The current log space reservation code allows multiple wakeups of the same sleeping waiter to happen. This is a just a waste of cpu time as well as increasing spin lock hold time. So a new XLOG_TIC_WAKING flag is added to track if a task is being waken up and skip the wake_up_process() call if the