From: Christoph Hellwig <hch@infradead.org>
To: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"dm-devel@redhat.com" <dm-devel@redhat.com>
Subject: Re: RFC: REQ_PRIO use
Date: Tue, 20 Nov 2018 01:39:07 -0800 [thread overview]
Message-ID: <20181120093907.GA32682@infradead.org> (raw)
In-Reply-To: <BN3PR0401MB1640F33FA8F3FFF251DF8266E7D90@BN3PR0401MB1640.namprd04.prod.outlook.com>
We have two places that check the flag, the writeback tracking
code:
block/blk-wbt.c:#define REQ_HIPRIO (REQ_SYNC | REQ_META | REQ_PRIO)
block/blk-wbt.c: if ((rw & REQ_HIPRIO) || wb_recent_wait(rwb) || current_is_kswapd())
and bcache:
drivers/md/bcache/request.c: !(bio->bi_opf & REQ_PRIO))
drivers/md/bcache/request.c: !(bio->bi_opf & REQ_PRIO) &&
the original idea was that not all I/O is a priority we should not
blindly boost priority for metadata. Of course wbt actually ignores
and it and we may just give in and just check REQ_META, except for
the fact that f2fs now actually submits REQ_PRIO requests without
REQ_META..
next prev parent reply other threads:[~2018-11-20 20:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-20 6:07 RFC: REQ_PRIO use Damien Le Moal
2018-11-20 9:39 ` Christoph Hellwig [this message]
2018-11-21 2:37 ` Damien Le Moal
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