Refresh

This website lore-kernel.gnuweeb.org/all/20020612233306.Z27449@parcelfarce.linux.theplanet.co.uk/ is currently offline. Cloudflare\'s Always Online™ shows a snapshot of this web page from the Internet Archive\'s Wayback Machine. To check for the live version, click Refresh.

All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@debian.org>
To: Saurabh Desai <sdesai@austin.ibm.com>
Cc: Matthew Wilcox <willy@debian.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Linus Torvalds <torvalds@transmeta.com>,
	Marcelo Tosatti <marcelo@conectiva.com.br>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fs/locks.c: Fix posix locking for threaded tasks
Date: Wed, 12 Jun 2002 23:33:06 +0100	[thread overview]
Message-ID: <20020612233306.Z27449@parcelfarce.linux.theplanet.co.uk> (raw)
In-Reply-To: <20020610034843.W27186@parcelfarce.linux.theplanet.co.uk> <E17I4bn-0007Rn-00@the-village.bc.nu> <20020612124536.T27449@parcelfarce.linux.theplanet.co.uk> <3D07C8D0.60B49C6D@austin.ibm.com>

On Wed, Jun 12, 2002 at 05:18:56PM -0500, Saurabh Desai wrote:
> Yes, it's needed for M:N threading library. Here is scenario: Task A
> holds a lock and waiting for some event in library, now task B tries
> to acquire that lock and waits in kernel and this can create a deadlock.
> These tasks are created with CLONE_THREAD (for M:N) flag. 
> This change (removing pid check) may cause problem for 1:1 (linuxthreads),
> where each task has unique pid and tgid. Again, whether that's a right 
> behavior or not is questionable. 
> However, with CLONE_THREAD flag, all tasks shares "tgid" value with unique
> pid and that's why I suggested earlier to change the "fl_pid" from "pid" 
> to "tgid" and it works for both the cases (M:N and 1:1).

But then we have different behaviour for applications which are linked
against a 1:1 library and an M:N library.  That makes no sense.

-- 
Revolutions do not require corporate support.

      reply	other threads:[~2002-06-12 22:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-06-10  2:48 [PATCH] fs/locks.c: Fix posix locking for threaded tasks Matthew Wilcox
2002-06-10  6:41 ` Andreas Dilger
2002-06-10 12:41   ` Matthew Wilcox
2002-06-10 20:30     ` Matthew Wilcox
2002-06-12  9:40 ` Alan Cox
2002-06-12 11:45   ` Matthew Wilcox
2002-06-12 22:18     ` Saurabh Desai
2002-06-12 22:33       ` Matthew Wilcox [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=20020612233306.Z27449@parcelfarce.linux.theplanet.co.uk \
    --to=willy@debian.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marcelo@conectiva.com.br \
    --cc=sdesai@austin.ibm.com \
    --cc=sfr@canb.auug.org.au \
    --cc=torvalds@transmeta.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.