From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Date: Mon, 11 Oct 2010 14:16:43 -0700 Subject: [Ocfs2-devel] [PATCH 1/1] Ocfs2: Add a mount option "coherency=*" to handle cluster coherency for O_DIRECT writes. In-Reply-To: <1286786799-10230-1-git-send-email-tristan.ye@oracle.com> References: <1286786799-10230-1-git-send-email-tristan.ye@oracle.com> Message-ID: <20101011211643.GH4255@mail.oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com On Mon, Oct 11, 2010 at 04:46:39PM +0800, Tristan Ye wrote: > Currently, default behavior of O_DIRECT writes was allowing > concurrent writing among nodes, no cluster coherency guaranteed > (no EX locks was taken), it hurts buffered reads on other nodes > by reading stale data from cache. > > The new mount option introduce a chance to choose two different > behaviors for O_DIRECT writes: > > * coherency=full, as the default value, will disallow > concurrent O_DIRECT writes by taking > EX locks. > > * coherency=buffered, allow concurrent O_DIRECT writes > without EX lock among nodes, which > gains high performance at risk of > getting stale data on other nodes. > > Signed-off-by: Tristan Ye This patch is now in the merge-window branch of ocfs2.git. Joel -- Life's Little Instruction Book #173 "Be kinder than necessary." Joel Becker Consulting Software Developer Oracle E-mail: joel.becker at oracle.com Phone: (650) 506-8127