* Dave Chinner: > On Sun, Jan 13, 2013 at 01:49:41PM -0600, Ben Myers wrote: >> On Sun, Jan 13, 2013 at 11:36:27AM -0500, Bradley C. Kuszmaul wrote: >> > On Sun, Jan 13, 2013 at 4:26 AM, Florian Weimer <fw@xxxxxxxxxxxxx> wrote: >> > > I once was a heavy Berkeley DB user and had files with dozens >> > > of gigabytes containing hundreds of thousands of extents, and >> > > open() times in the order of minutes were not unusual with a >> > > cold cache and other concurrent read activities from the same >> > > RAID device. >> >> Ouch. I would not have expected open times that bad. > > That will only happen if the extent list needs to be read during the > open() call. That will only occur if O_TRUNC is set. Otherwise, the > extents are read on the first syscall that needs them to be read in > (read, write, alloc, punch, truncate, etc) and that's when the > latency occurs. Indeed, I think I have misremembered. The delay occurred when Berkeley DB tried to read the first page from disk. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
