LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jarek Poplawski <jarkao2@o2.pl>
To: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	David Howells <dhowells@redhat.com>,
	David Miller <davem@davemloft.net>, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cancel_delayed_work: use del_timer() instead of del_timer_sync()
Date: Fri, 27 Apr 2007 08:15:06 +0200	[thread overview]
Message-ID: <20070427061506.GC997@ff.dom.local> (raw)
In-Reply-To: <20070426152953.GA1824@tv-sign.ru>

On Thu, Apr 26, 2007 at 07:29:53PM +0400, Oleg Nesterov wrote:
> On 04/26, Jarek Poplawski wrote:
...
> > > This change should not make any visible difference for the callers,
> > > otherwise it is buggy.
> > 
> > IMHO, there is the same visible difference,
> > as between del_timer and del_timer_sync.
> 
> Jarek, please, could you be more explicite ? del_timer() and
> del_timer_sync() are different in many ways. What exactly will
> impact the user of cancel_delaye_work ?

OK, I changed my mind. Now, I think it's very probable
this should matter...

According to workqueue.h:
> /*
>  * Kill off a pending schedule_delayed_work().  Note that the work callback
>  * function may still be running on return from cancel_delayed_work().  Run
>  * flush_workqueue() or cancel_work_sync() to wait on it.
>  */
> static inline int cancel_delayed_work(struct delayed_work *work)

So, we can do something like this:

cancel_delayed_work(dwork);
flush_workqueue(wq);
kfree(some_obj_used_by_dwork_func);

And this is enough to work with not rearming work.

But no more after this patch...

So, I think, your proposal should be alternative version,
and current version should stay, so we have a choice.
Just like del_timer and del_timer_sync.

Jarek P.

  reply	other threads:[~2007-04-27  6:09 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-24 21:50 Oleg Nesterov
2007-04-25 10:04 ` David Howells
2007-04-25 13:02 ` Jarek Poplawski
2007-04-25 12:52   ` Oleg Nesterov
2007-04-26 14:29     ` Jarek Poplawski
2007-04-26 15:29       ` Oleg Nesterov
2007-04-27  6:15         ` Jarek Poplawski [this message]
2007-04-27  7:23           ` Oleg Nesterov

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=20070427061506.GC997@ff.dom.local \
    --to=jarkao2@o2.pl \
    --cc=akpm@linux-foundation.org \
    --cc=davem@davemloft.net \
    --cc=dhowells@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=oleg@tv-sign.ru \
    --subject='Re: [PATCH] cancel_delayed_work: use del_timer() instead of del_timer_sync()' \
    /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

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).