From: David Howells <dhowells@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: dhowells@redhat.com, "Török Edwin" <edwin@clamav.net>,
"Ingo Molnar" <mingo@elte.hu>,
"Linux Kernel" <linux-kernel@vger.kernel.org>,
aCaB <acab@clamav.net>, "Nick Piggin" <npiggin@suse.de>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Thomas Gleixner" <tglx@linutronix.de>
Subject: Re: Mutex vs semaphores scheduler bug
Date: Fri, 16 Oct 2009 00:44:26 +0100 [thread overview]
Message-ID: <24718.1255650266@redhat.com> (raw)
In-Reply-To: <1255359207.10420.31.camel@twins>
Peter Zijlstra <peterz@infradead.org> wrote:
> The problem appears to be that rwsem doesn't allow lock-stealing
With good reason. rwsems can be read or write locked for a long time - so if
readers can jump the queue on read-locked rwsems, then writer starvation is a
real possibility. I carefully implemented it so that it is a strict FIFO to
avoid certain problems I was having.
David
next prev parent reply other threads:[~2009-10-15 23:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-10 14:57 Mutex vs semaphores scheduler bug Török Edwin
2009-10-12 14:53 ` Peter Zijlstra
2009-10-12 15:37 ` Török Edwin
2009-10-15 23:44 ` David Howells [this message]
2009-10-17 15:32 ` Peter Zijlstra
2009-10-20 19:02 ` Török Edwin
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