Hello, I'm writing an application that makes pretty extensive use of extended attributes to store file attributes on Ext2. I used a profiling tool developed by my colleague Nikolai Joukov at SUNY Stony Brook to dig a bit deeper into the performance of my application. In the course of my benchmark, there are 54247 setxattr operations during a 54 seconds. They use about 10.56 seconds of the time, which seemed to be a rather outsized performance toll to me (~40k writes took only 10% as long). After looking at the profile, 27 of those writes end up taking 7.74 seconds. That works out to roughly 286 ms per call; which seems a bit high. The workload is not memory constrained (the working set is 50MB + 5000 files). Each file has one extended attribute block that contains two attributes totaling 32 bytes. The attributes are unique (random actually), so there isn't any sharing. Can someone provide me with some intuition as to why there are so many writes that reach the disk, and why they take so long. I would expect that the operations shouldn't take much longer than a seek (on the order of 10ms, not 200+)? Charles _______________________________________________ Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
