From: Al Viro <viro@ZenIV.linux.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@osdl.org>, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Nick Piggin <npiggin@kernel.dk>
Subject: Re: [patch 0/5] seqlock consolidation
Date: Thu, 15 Mar 2012 17:43:06 +0000 [thread overview]
Message-ID: <20120315174305.GD8943@ZenIV.linux.org.uk> (raw)
In-Reply-To: <alpine.LFD.2.02.1203151322020.2466@ionos>
On Thu, Mar 15, 2012 at 01:28:03PM +0100, Thomas Gleixner wrote:
> The only way out is to lock d->d_lock which is contended, so the
> reader side boosts the writer and waits for the lock to be
> released. Though with the open coded seqlock we have no idea which
> lock we need to take.
>
> Any better ideas ?
So basically you want RT stuff to know that several areas in fs/dcache.c
(from write_seqcount_begin() to write_seqcount_end()) are protected by
(already held by that point) ->d_lock of corresponding dentries?
If that's it, I suggest to look for a solution that would express just that...
Or do you want something on the reader side as well?
next prev parent reply other threads:[~2012-03-15 17:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-15 11:44 [patch 0/5] seqlock consolidation Thomas Gleixner
2012-03-15 11:44 ` [patch 1/5] seqlock: Remove unused functions Thomas Gleixner
2012-03-15 16:29 ` Linus Torvalds
2012-03-15 17:39 ` Al Viro
2012-03-15 17:53 ` Thomas Gleixner
2012-03-15 11:44 ` [patch 2/5] seqlock: Use seqcount for seqlock Thomas Gleixner
2012-03-15 11:44 ` [patch 3/5] seqlock: Provide seq_spin_* functions Thomas Gleixner
2012-03-15 11:44 ` [patch 4/5] fs: fs_struct use seqlock Thomas Gleixner
2012-03-15 11:44 ` [patch 5/5] fs: Use seqlock in struct dentry Thomas Gleixner
2012-03-15 12:21 ` [patch 0/5] seqlock consolidation Al Viro
2012-03-15 12:28 ` Thomas Gleixner
2012-03-15 17:43 ` Al Viro [this message]
2012-03-15 17:55 ` Thomas Gleixner
2012-03-15 18:39 ` Al Viro
2012-03-15 19:17 ` Thomas Gleixner
2012-03-15 20:42 ` Al Viro
2012-03-15 22:08 ` Thomas Gleixner
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