On Thu, Sep 01, 2011 at 05:46:40PM -0400, Christoph Hellwig wrote: > On Thu, Sep 01, 2011 at 02:22:15PM -0500, Alex Elder wrote: > > that the buffer should be queued at unlock time, we now > > just put it in the queue right away. Seems reasonable. > > Do you know why enqueueing it was delayed before? > > I don't know why - it's a carryover from IRIX days, Right. On Irix a buffer could simply have the BUF_DELWRI flag set on it, and the buffer cache would take care of everything else. There wasn't a specific delayed write list in Irix, instead there was a fixed table of buffers (large!) that was scanned every 5 seconds (20% scanned once per second) and the delwri buffers were gathered by the scan. Hence there were places in XFS where it simply set the flag to mark a buffer delwri, and that's what this Linux code had to catch. > so long before my time. The XFS code long predates me, too, but I spend a couple of years in the trenches around the Irix buffer cache when I was at SGI so I at least know why it was like that. ;) Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
