linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Ming Lei <ming.lei@canonical.com>
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@fb.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Maxim Patlasov <mpatlasov@parallels.com>
Subject: Re: [PATCH 1/3] block: loop: use kmap(page) instead of page_address(page)
Date: Tue, 24 Mar 2015 12:09:51 +0100	[thread overview]
Message-ID: <20150324110951.GA7979@lst.de> (raw)
In-Reply-To: <CACVXFVMcC4G5s0-JT1Z8APup18MKwGAkN7qyubxDW-ByTVxtRA@mail.gmail.com>

On Tue, Mar 24, 2015 at 06:49:00PM +0800, Ming Lei wrote:
> On 32bit system, this still may cause pressure on page allocation, since
> requests are handled concurrently now after using workqueue.

kmap slots are from a much smaller resource pool than non-highmem
allocations, so if a page needs to stay kmaped from allocation time until
freeing it it should just be allocated as a kernel mapped page.

  reply	other threads:[~2015-03-24 11:09 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-22  8:14 [PATCH 0/3] block: loop: switch to VFS ITER_BVEC Ming Lei
2015-03-22  8:14 ` [PATCH 1/3] block: loop: use kmap(page) instead of page_address(page) Ming Lei
2015-03-24 10:29   ` Christoph Hellwig
2015-03-24 10:49     ` Ming Lei
2015-03-24 11:09       ` Christoph Hellwig [this message]
2015-03-24 11:24         ` Ming Lei
2015-03-22  8:14 ` [PATCH 2/3] block: loop: unify interface type of lo_send and lo_receive Ming Lei
2015-03-24 10:30   ` Christoph Hellwig
2015-03-24 10:55     ` Ming Lei
2015-03-22  8:14 ` [PATCH 3/3] block: loop: use vfs ITER_BVEC to read/write backing file Ming Lei
2015-03-24 10:31   ` Christoph Hellwig
2015-03-24 11:01     ` Ming Lei
2015-03-24 10:32 ` [PATCH 0/3] block: loop: switch to VFS ITER_BVEC Christoph Hellwig
2015-03-24 10:53   ` Ming Lei
2015-03-24 18:01     ` Christoph Hellwig
2015-03-25  7:23       ` Ming Lei
2015-03-25 15:27         ` Christoph Hellwig
2015-03-31 22:22           ` Al Viro
2015-04-04  5:20           ` Al Viro
2015-04-07 16:23             ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150324110951.GA7979@lst.de \
    --to=hch@lst.de \
    --cc=axboe@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ming.lei@canonical.com \
    --cc=mpatlasov@parallels.com \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).