Eric Sandeen wrote: > running fs_mark like this: > > fs_mark -d /mnt/test -D 256 -n 100000 -t 4 -s 20480 -F -S 0 > > (256 subdirs, 100000 files/iteration, 4 threads, 20k files, no sync) > > on a 1T fs, with and without delalloc (mount option), is pretty interesting: > > http://people.redhat.com/esandeen/ext4/fs_mark.png > > somehow delalloc is crushing performance here. I'm planning to wait > 'til the fs is full and see what the effect is on fsck, and look at the > directory layout for differences compared to w/o delalloc. > > But something seems to have gone awry here ... > > This is on 2.6.26 with the patch queue applied up to stable. > > -Eric I oprofiled both with and without delalloc for the first 15% of the fs fill: ==> delalloc.op <== CPU: AMD64 processors, speed 2000 MHz (estimated) Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit mask of 0x00 (No unit mask) count 100000 samples % image name app name symbol name 56094537 73.6320 ext4dev.ko ext4dev ext4_mb_use_preallocated 642479 0.8433 vmlinux vmlinux __copy_user_nocache 523803 0.6876 vmlinux vmlinux memcmp 482874 0.6338 jbd2.ko jbd2 do_get_write_access 480687 0.6310 vmlinux vmlinux kmem_cache_free 403604 0.5298 ext4dev.ko ext4dev str2hashbuf 400471 0.5257 vmlinux vmlinux __find_get_block ==> nodelalloc.op <== CPU: AMD64 processors, speed 2000 MHz (estimated) Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit mask of 0x00 (No unit mask) count 100000 samples % image name app name symbol name 56167198 56.8949 ext4dev.ko ext4dev ext4_mb_use_preallocated 1524662 1.5444 jbd2.ko jbd2 do_get_write_access 1234776 1.2508 vmlinux vmlinux __copy_user_nocache 1115267 1.1297 jbd2.ko jbd2 jbd2_journal_add_journal_head 1053102 1.0667 vmlinux vmlinux __find_get_block 963646 0.9761 vmlinux vmlinux kmem_cache_free 958804 0.9712 vmlinux vmlinux memcmp not sure if this points to anything or not - but ext4_mb_use_preallocated is working awfully hard in both cases :) -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
