Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Dave Chinner
On Mon, Oct 02, 2017 at 04:08:46PM -0700, Linus Torvalds wrote: > On Mon, Oct 2, 2017 at 3:45 PM, Dave Chinner wrote: > > > > Yup, it's a good idea. Needs some tweaking, though. > > Probably a lot. 256kB seems very eager. > > > If we block on close, it becomes: > > I'm not at all suggesting blo

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Linus Torvalds
On Mon, Oct 2, 2017 at 3:45 PM, Dave Chinner wrote: > > Yup, it's a good idea. Needs some tweaking, though. Probably a lot. 256kB seems very eager. > If we block on close, it becomes: I'm not at all suggesting blocking at cl;ose, just doing that final async writebehind (assuming we started any

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Dave Chinner
On Mon, Oct 02, 2017 at 12:54:53PM -0700, Linus Torvalds wrote: > On Mon, Oct 2, 2017 at 2:54 AM, Konstantin Khlebnikov > wrote: > > > > This patch implements write-behind policy which tracks sequential writes > > and starts background writeback when have enough dirty pages in a row. > > This loo

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Andreas Dilger
On Oct 2, 2017, at 10:58 PM, Konstantin Khlebnikov wrote: > > On 02.10.2017 22:54, Linus Torvalds wrote: >> On Mon, Oct 2, 2017 at 2:54 AM, Konstantin Khlebnikov >> wrote: >>> >>> This patch implements write-behind policy which tracks sequential writes >>> and starts background writeback when

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Konstantin Khlebnikov
On 02.10.2017 23:00, Jens Axboe wrote: On 10/02/2017 03:54 AM, Konstantin Khlebnikov wrote: Traditional writeback tries to accumulate as much dirty data as possible. This is worth strategy for extremely short-living files and for batching writes for saving battery power. But for workloads where

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Konstantin Khlebnikov
On 02.10.2017 22:54, Linus Torvalds wrote: On Mon, Oct 2, 2017 at 2:54 AM, Konstantin Khlebnikov wrote: This patch implements write-behind policy which tracks sequential writes and starts background writeback when have enough dirty pages in a row. This looks lovely to me. I do wonder if you

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Jens Axboe
On 10/02/2017 03:54 AM, Konstantin Khlebnikov wrote: > Traditional writeback tries to accumulate as much dirty data as possible. > This is worth strategy for extremely short-living files and for batching > writes for saving battery power. But for workloads where disk latency is > important this pol

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Linus Torvalds
On Mon, Oct 2, 2017 at 2:54 AM, Konstantin Khlebnikov wrote: > > This patch implements write-behind policy which tracks sequential writes > and starts background writeback when have enough dirty pages in a row. This looks lovely to me. I do wonder if you also looked at finishing the background w

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Konstantin Khlebnikov
On 02.10.2017 14:23, Florian Weimer wrote: On 10/02/2017 11:54 AM, Konstantin Khlebnikov wrote: This patch implements write-behind policy which tracks sequential writes and starts background writeback when have enough dirty pages in a row. Does this apply to data for files which have never bee

Re: [PATCH RFC] mm: implement write-behind policy for sequential file writes

2017-10-02 Thread Florian Weimer
On 10/02/2017 11:54 AM, Konstantin Khlebnikov wrote: This patch implements write-behind policy which tracks sequential writes and starts background writeback when have enough dirty pages in a row. Does this apply to data for files which have never been written to disk before? I think one of