linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Dennis Zhou <dennis@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: Dennis Zhou <dennis@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>,
	Josef Bacik <josef@toxicpanda.com>,
	kernel-team@fb.com, linux-block@vger.kernel.org,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 05/13] blkcg: associate blkg when associating a device
Date: Mon, 3 Dec 2018 17:52:22 -0500	[thread overview]
Message-ID: <20181203225222.GA3801@dennisz-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20181130095426.GB17103@infradead.org>

On Fri, Nov 30, 2018 at 01:54:26AM -0800, Christoph Hellwig wrote:
> > diff --git a/include/linux/bio.h b/include/linux/bio.h
> > index 62715a5a4f32..8bc9d9b29fd3 100644
> > --- a/include/linux/bio.h
> > +++ b/include/linux/bio.h
> > @@ -486,6 +486,12 @@ extern unsigned int bvec_nr_vecs(unsigned short idx);
> >  extern const char *bio_devname(struct bio *bio, char *buffer);
> >  
> >  #define bio_set_dev(bio, bdev) 			\
> > +do {						\
> > +	bio_set_dev_only(bio, bdev);		\
> > +	bio_associate_blkg(bio);		\
> > +} while (0)
> > +
> > +#define bio_set_dev_only(bio, bdev)		\
> 
> This lacks any explanation on when you would use bio_set_dev_only or
> bio_set_dev.  Please document why we need both and why you'd choose or
> the other.

I realized after thinking about this more and checking more use cases
that it isn't as simple as swapping macro uses because many of the
callers share common bio allocation paths. I think the simplest way
forward is to have writeback and swap do reassociation and split out bio
init code in a future series. So in v5, there is only bio_set_dev().

Thanks,
Dennis

  reply	other threads:[~2018-12-03 22:52 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-26 21:19 [PATCH 00/13 v4] block: always associate blkg and refcount cleanup Dennis Zhou
2018-11-26 21:19 ` [PATCH 01/13] blkcg: fix ref count issue with bio_blkcg() using task_css Dennis Zhou
2018-11-27 20:54   ` Josef Bacik
2018-11-26 21:19 ` [PATCH 02/13] blkcg: update blkg_lookup_create() to do locking Dennis Zhou
2018-11-27 20:56   ` Josef Bacik
2018-11-26 21:19 ` [PATCH 03/13] blkcg: convert blkg_lookup_create() to find closest blkg Dennis Zhou
2018-11-27 21:01   ` Josef Bacik
2018-11-26 21:19 ` [PATCH 04/13] blkcg: introduce common blkg association logic Dennis Zhou
2018-11-27 21:04   ` Josef Bacik
2018-11-29 15:49   ` Tejun Heo
2018-11-29 19:48     ` Dennis Zhou
2018-11-30  9:52   ` Christoph Hellwig
2018-12-03 20:58     ` Dennis Zhou
2018-11-26 21:19 ` [PATCH 05/13] blkcg: associate blkg when associating a device Dennis Zhou
2018-11-29 15:53   ` Tejun Heo
2018-11-29 19:54     ` Dennis Zhou
2018-11-30  9:54   ` Christoph Hellwig
2018-12-03 22:52     ` Dennis Zhou [this message]
2018-11-26 21:19 ` [PATCH 06/13] blkcg: consolidate bio_issue_init() to be a part of core Dennis Zhou
2018-11-26 21:19 ` [PATCH 07/13] blkcg: associate a blkg for pages being evicted by swap Dennis Zhou
2018-11-26 21:19 ` [PATCH 08/13] blkcg: associate writeback bios with a blkg Dennis Zhou
2018-11-26 21:19 ` [PATCH 09/13] blkcg: remove bio->bi_css and instead use bio->bi_blkg Dennis Zhou
2018-11-26 21:19 ` [PATCH 10/13] blkcg: remove additional reference to the css Dennis Zhou
2018-11-26 21:19 ` [PATCH 11/13] blkcg: remove bio_disassociate_task() Dennis Zhou
2018-11-29 15:54   ` Tejun Heo
2018-11-26 21:19 ` [PATCH 12/13] blkcg: change blkg reference counting to use percpu_ref Dennis Zhou
2018-11-26 21:19 ` [PATCH 13/13] blkcg: rename blkg_try_get() to blkg_tryget() Dennis Zhou
2018-11-27 21:10 ` [PATCH 00/13 v4] block: always associate blkg and refcount cleanup Josef Bacik
2018-11-27 22:15   ` Dennis Zhou

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=20181203225222.GA3801@dennisz-mbp.dhcp.thefacebook.com \
    --to=dennis@kernel.org \
    --cc=axboe@kernel.dk \
    --cc=cgroups@vger.kernel.org \
    --cc=hannes@cmpxchg.org \
    --cc=hch@infradead.org \
    --cc=josef@toxicpanda.com \
    --cc=kernel-team@fb.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tj@kernel.org \
    /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).