From: Minchan Kim <minchan@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
Jerome Marchand <jmarchan@redhat.com>,
linux-nvdimm@lists.01.org, Dave Chinner <david@fromorbit.com>,
linux-kernel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
seungho1.park@lge.com, Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
"karam . lee" <karam.lee@lge.com>,
Nitin Gupta <ngupta@vflare.org>
Subject: Re: [PATCH 0/3] remove rw_page() from brd, pmem and btt
Date: Mon, 31 Jul 2017 16:36:47 +0900 [thread overview]
Message-ID: <20170731073647.GA26199@bbox> (raw)
In-Reply-To: <20170731071707.GA16299@lst.de>
On Mon, Jul 31, 2017 at 09:17:07AM +0200, Christoph Hellwig wrote:
> On Mon, Jul 31, 2017 at 07:16:59AM +0900, Minchan Kim wrote:
> > rw_page's gain is reducing of dynamic allocation in swap path
> > as well as performance gain thorugh avoiding bio allocation.
> > And it would be important in memory pressure situation.
>
> There is no need for any dynamic allocation when using the bio
> path. Take a look at __blkdev_direct_IO_simple for an example
> that doesn't do any allocations.
Do you suggest define something special flag(e.g., SWP_INMEMORY)
for in-memory swap to swap_info_struct when swapon time manually
or from bdi_queue_someting automatically?
And depending the flag of swap_info_struct, use the onstack bio
instead of dynamic allocation if the swap device is in-memory?
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WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
linux-kernel@vger.kernel.org, "karam . lee" <karam.lee@lge.com>,
Jerome Marchand <jmarchan@redhat.com>,
Nitin Gupta <ngupta@vflare.org>,
seungho1.park@lge.com, Dan Williams <dan.j.williams@intel.com>,
Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.cz>,
Jens Axboe <axboe@kernel.dk>,
Vishal Verma <vishal.l.verma@intel.com>,
linux-nvdimm@lists.01.org
Subject: Re: [PATCH 0/3] remove rw_page() from brd, pmem and btt
Date: Mon, 31 Jul 2017 16:36:47 +0900 [thread overview]
Message-ID: <20170731073647.GA26199@bbox> (raw)
In-Reply-To: <20170731071707.GA16299@lst.de>
On Mon, Jul 31, 2017 at 09:17:07AM +0200, Christoph Hellwig wrote:
> On Mon, Jul 31, 2017 at 07:16:59AM +0900, Minchan Kim wrote:
> > rw_page's gain is reducing of dynamic allocation in swap path
> > as well as performance gain thorugh avoiding bio allocation.
> > And it would be important in memory pressure situation.
>
> There is no need for any dynamic allocation when using the bio
> path. Take a look at __blkdev_direct_IO_simple for an example
> that doesn't do any allocations.
Do you suggest define something special flag(e.g., SWP_INMEMORY)
for in-memory swap to swap_info_struct when swapon time manually
or from bdi_queue_someting automatically?
And depending the flag of swap_info_struct, use the onstack bio
instead of dynamic allocation if the swap device is in-memory?
next prev parent reply other threads:[~2017-07-31 7:34 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-28 16:56 [PATCH 0/3] remove rw_page() from brd, pmem and btt Ross Zwisler
2017-07-28 16:56 ` Ross Zwisler
2017-07-28 16:56 ` [PATCH 1/3] btt: remove btt_rw_page() Ross Zwisler
2017-07-28 16:56 ` Ross Zwisler
2017-08-03 16:15 ` kbuild test robot
2017-08-03 16:15 ` kbuild test robot
2017-07-28 16:56 ` [PATCH 2/3] pmem: remove pmem_rw_page() Ross Zwisler
2017-07-28 16:56 ` Ross Zwisler
2017-07-28 16:56 ` [PATCH 3/3] brd: remove brd_rw_page() Ross Zwisler
2017-07-28 16:56 ` Ross Zwisler
2017-07-28 17:31 ` [PATCH 0/3] remove rw_page() from brd, pmem and btt Matthew Wilcox
2017-07-28 17:31 ` Matthew Wilcox
2017-07-28 21:21 ` Andrew Morton
2017-07-28 21:21 ` Andrew Morton
2017-07-30 22:16 ` Minchan Kim
2017-07-30 22:16 ` Minchan Kim
2017-07-30 22:38 ` Minchan Kim
2017-07-30 22:38 ` Minchan Kim
2017-07-31 7:17 ` Christoph Hellwig
2017-07-31 7:17 ` Christoph Hellwig
2017-07-31 7:36 ` Minchan Kim [this message]
2017-07-31 7:36 ` Minchan Kim
2017-07-31 7:42 ` Christoph Hellwig
2017-07-31 7:42 ` Christoph Hellwig
2017-07-31 7:44 ` Christoph Hellwig
2017-07-31 7:44 ` Christoph Hellwig
2017-08-01 6:23 ` Minchan Kim
2017-08-01 6:23 ` Minchan Kim
2017-08-02 22:13 ` Ross Zwisler
2017-08-02 22:13 ` Ross Zwisler
2017-08-03 0:13 ` Minchan Kim
2017-08-03 0:13 ` Minchan Kim
2017-08-03 0:34 ` Dan Williams
2017-08-03 0:34 ` Dan Williams
2017-08-03 8:05 ` Christoph Hellwig
2017-08-03 8:05 ` Christoph Hellwig
2017-08-04 0:57 ` Minchan Kim
2017-08-04 0:57 ` Minchan Kim
2017-08-03 21:13 ` Ross Zwisler
2017-08-03 21:13 ` Ross Zwisler
2017-08-03 21:17 ` Jens Axboe
2017-08-03 21:17 ` Jens Axboe
2017-08-04 3:54 ` Minchan Kim
2017-08-04 3:54 ` Minchan Kim
2017-08-04 8:17 ` Minchan Kim
2017-08-04 8:17 ` Minchan Kim
2017-08-04 18:01 ` Dan Williams
2017-08-04 18:01 ` Dan Williams
2017-08-04 18:21 ` Ross Zwisler
2017-08-04 18:21 ` Ross Zwisler
2017-08-04 18:24 ` Dan Williams
2017-08-04 18:24 ` Dan Williams
2017-08-07 8:23 ` Minchan Kim
2017-08-07 8:23 ` Minchan Kim
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