Anyone got any comments on this with respect to XFS?
DSL
-------- Original Message --------
Subject: [reiserfs-list] Pingpong-Journaling in reiser4?
Date: Thu, 30 Aug 2001 23:30:16 +0200
From: Xuan Baldauf <xuan--reiserfs@xxxxxxxxxxx>
Organization: Medium.net
To: Hans Reiser <reiser@xxxxxxxxxxx>
CC: reiserfs-list@xxxxxxxxxxx
Hello Hans,
are you considering pingpong-journaling for reiser4?
Ping-Pong journaling is that, in the case you are able to
know that the blocks you are writing to will be overwritten
due to outstanding requests|future transactions, you do not
write the invalidation block of the old transaction until
the affected blocks are overwritten by the new transaction.
Doing journaling in that way, you are bringing the count of
required writes for journaling to the count of required
writes for non-journaling (1 changed block, 1 write instead
of 1 changed block, 1 write to the journal and 1 write to
the real location), and thus saving half the
journal-related writes in the ideal case. The superblock is
a good candidate for this feature.
I think that heavily loaded servers with parallel disk
writes will be able to see a considerable speedup.
Xuân.
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