Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-03 Thread Shaohua Li
On Mon, Dec 01, 2014 at 07:43:37PM -0700, Jens Axboe wrote: > On 12/01/2014 11:59 AM, Shaohua Li wrote: > >On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: > >>On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: > >>>On 11/30/2014 05:01 PM, Shaohua Li wrote: > Buffer read is

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-03 Thread Shaohua Li
On Mon, Dec 01, 2014 at 07:43:37PM -0700, Jens Axboe wrote: On 12/01/2014 11:59 AM, Shaohua Li wrote: On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-01 Thread Jens Axboe
On 12/01/2014 11:59 AM, Shaohua Li wrote: On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-01 Thread Shaohua Li
On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: > On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: > > On 11/30/2014 05:01 PM, Shaohua Li wrote: > > >Buffer read is counted as sync in rw_is_sync(). If we use it, > > >blk_sq_make_request() will not do per-process plug any

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-01 Thread Jens Axboe
On 12/01/2014 11:59 AM, Shaohua Li wrote: On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-12-01 Thread Shaohua Li
On Sun, Nov 30, 2014 at 07:57:12PM -0800, Shaohua Li wrote: On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Shaohua Li
On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: > On 11/30/2014 05:01 PM, Shaohua Li wrote: > >Buffer read is counted as sync in rw_is_sync(). If we use it, > >blk_sq_make_request() will not do per-process plug any more. > > > >I haven't changed blk_mq_make_request() yet. It makes

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Jens Axboe
On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I haven't changed blk_mq_make_request() yet. It makes sense to dispatch REQ_SYNC request immediately. But for buffer read, it's

[PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Shaohua Li
Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I haven't changed blk_mq_make_request() yet. It makes sense to dispatch REQ_SYNC request immediately. But for buffer read, it's weird not to do per-process plug, as buffer

[PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Shaohua Li
Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I haven't changed blk_mq_make_request() yet. It makes sense to dispatch REQ_SYNC request immediately. But for buffer read, it's weird not to do per-process plug, as buffer

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Jens Axboe
On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I haven't changed blk_mq_make_request() yet. It makes sense to dispatch REQ_SYNC request immediately. But for buffer read, it's

Re: [PATCH] blk-mq: don't use rw_is_sync() to determine sync request

2014-11-30 Thread Shaohua Li
On Sun, Nov 30, 2014 at 06:35:11PM -0700, Jens Axboe wrote: On 11/30/2014 05:01 PM, Shaohua Li wrote: Buffer read is counted as sync in rw_is_sync(). If we use it, blk_sq_make_request() will not do per-process plug any more. I haven't changed blk_mq_make_request() yet. It makes sense to