linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Uladzislau Rezki <urezki@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	Nicholas Piggin <npiggin@gmail.com>,
	Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Subject: Re: [PATCH 1/3] mm/vmalloc: Move draining areas out of caller context
Date: Thu, 20 Jan 2022 11:42:56 +0100	[thread overview]
Message-ID: <Yek8sHMQuLZb3nCM@pc638.lan> (raw)
In-Reply-To: <YeknfRnxaxcVxEjF@infradead.org>

> On Wed, Jan 19, 2022 at 03:35:38PM +0100, Uladzislau Rezki (Sony) wrote:
> > +static void drain_vmap_area(struct work_struct *work)
> 
> Nit, but I prefer to have a _work postix for workers just to keep
> it easy to ready.
> 
Will fix it!

> >  	/* After this point, we may free va at any time */
> >  	if (unlikely(nr_lazy > lazy_max_pages()))
> > -		try_purge_vmap_area_lazy();
> > +		if (!atomic_xchg(&drain_vmap_area_work_in_progress, 1))
> > +			schedule_work(&drain_vmap_area_work);
> 
> Work items are defined to be single threaded, so I don't think we need
> the drain_vmap_area_work_in_progress hack.
> 
The motivation with that hack was to prevent the drain work being placed
several times at once, i.e. schedule_work() checks only a pending bit.

If the work is in run-queue another caller of vfree() will place it one
more time, since pending bit is not set because the work is in TASK_RUNNING
state.

Or am i missing something?

--
Vlad Rezki


      reply	other threads:[~2022-01-20 10:43 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-19 14:35 [PATCH 1/3] mm/vmalloc: Move draining areas out of caller context Uladzislau Rezki (Sony)
2022-01-19 14:35 ` [PATCH 2/3] mm/vmalloc: Add adjust_search_size parameter Uladzislau Rezki (Sony)
2022-01-19 14:35 ` [PATCH 3/3] mm/vmalloc: Eliminate an extra orig_gfp_mask Uladzislau Rezki (Sony)
2022-01-20  9:12 ` [PATCH 1/3] mm/vmalloc: Move draining areas out of caller context Christoph Hellwig
2022-01-20 10:42   ` Uladzislau Rezki [this message]

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=Yek8sHMQuLZb3nCM@pc638.lan \
    --to=urezki@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=hch@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=npiggin@gmail.com \
    --cc=oleksiy.avramchenko@sonymobile.com \
    --cc=willy@infradead.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).