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From: Valdis.Kletnieks@vt.edu
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicholas Krause <xerofoify@gmail.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm:Avoid soft lockup due to possible attempt of double locking object's lock in __delete_object
Date: Wed, 31 Aug 2016 17:08:26 -0400	[thread overview]
Message-ID: <33981.1472677706@turing-police.cc.vt.edu> (raw)
In-Reply-To: <20160831075421.GA15732@e104818-lin.cambridge.arm.com>

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On Wed, 31 Aug 2016 08:54:21 +0100, Catalin Marinas said:
> On Tue, Aug 30, 2016 at 02:35:12PM -0400, Nicholas Krause wrote:
> > This fixes a issue in the current locking logic of the function,
> > __delete_object where we are trying to attempt to lock the passed
> > object structure's spinlock again after being previously held
> > elsewhere by the kmemleak code. Fix this by instead of assuming
> > we are the only one contending for the object's lock their are
> > possible other users and create two branches, one where we get
> > the lock when calling spin_trylock_irqsave on the object's lock
> > and the other when the lock is held else where by kmemleak.
>
> Have you actually got a deadlock that requires this fix?

Almost certainly not, but that's never stopped Nicholas before.  He's a well-known
submitter of bad patches, usually totally incorrect, not even compile tested.

He's infamous enough that he's not allowed to post to any list hosted at vger.

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  parent reply	other threads:[~2016-08-31 21:09 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-30 18:35 [PATCH] mm:Avoid soft lockup due to possible attempt of double locking object's lock in __delete_object Nicholas Krause
2016-08-31  7:54 ` Catalin Marinas
2016-08-31  7:54   ` Catalin Marinas
2016-08-31 13:24   ` nick
2016-09-07  0:45     ` Rik van Riel
2016-08-31 13:41   ` nick
2016-08-31 14:35     ` Catalin Marinas
2016-08-31 14:35       ` Catalin Marinas
2016-08-31 21:08   ` Valdis.Kletnieks [this message]
2016-08-31 21:28     ` nick
2016-09-07  0:51       ` Rik van Riel
2016-09-07  1:12         ` nick
2016-09-07  1:22           ` Rik van Riel

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