https://bugzilla.novell.com/show_bug.cgi?id=700290 https://bugzilla.novell.com/show_bug.cgi?id=700290#c0 Summary: Terrible slow pwrite() (and lseek/write) speed on ext4 filesystem Classification: openSUSE Product: openSUSE 11.4 Version: Factory Platform: i686 OS/Version: openSUSE 11.4 Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: kernel-maintainers@forge.provo.novell.com ReportedBy: sergey1369@narod.ru QAContact: qa@suse.de Found By: --- Blocker: --- Created an attachment (id=434778) --> (http://bugzilla.novell.com/attachment.cgi?id=434778) Sample pwrite test program User-Agent: Mozilla/5.0 (X11; Linux i686; rv:2.0.1) Gecko/20100101 Firefox/4.0.1 I've got serious ext4fs performance problem on random write to large file (4GB). I've used attached program pwrite_test.c and found out that performance on same hardware is very different. On ext4 it takes about 1minute 26s, and on ext3 it takes 10seconds. I guess that something wrong with ext4 filesystem. Reproducible: Always Steps to Reproduce: # mkdir /mnt/sdb1 # mkfs.ext3 /dev/sdb1 # mount /dev/sdb1 /mnt/sdb1 # cc pwrite_test.c # time ./a.out Last sample writen at 4294901760 real 0m10.541s user 0m0.116s sys 0m1.314s # umount /dev/sdb1 # mkfs.ext4 /dev/sdb1 # mount /dev/sdb1 /mnt/sdb1 # time ./a.out Last sample writen at 4294901760 real 1m29.475s user 0m0.123s sys 0m0.805s Actual Results: (ext3) real time 0m10.541s (ext4) real 1m29.475s Expected Results: something about 10s for both filesystems.. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.