Laurent Riffard wrote: >Hello, > >Writing big files is very slow on reiser4 now. > >"dd if=/dev/zero of=toto bs=1k count=102400; sync" > try bs=4M, and tell me what happens. also try an empty fs, and an fs that is equally full to reiserfs. Note that reiserfs in your test is 68% full vs. 90% full for V4. It may be that we need to port some of the block allocation optimizations from V3 to V4 (Jeff's work) to help with 90% full filesystems. Thanks for doing this. Real users always teach me a lot when they test things differently from how I did.
Hans > takes more than 2 minutes on >reiser4 fs, but only 15 seconds on reiserfs fs. > >Actually, writing on reiser4 is not uniformly slow, it seems to be blocked for >ages from time to time. I monitored the number of dirty pages from >/proc/meminfo >an I hit sysrq-T when the system was stalling: > >dd D 000017DE 0 21930 21929 (NOTLB) > d7169c74 e0c98b05 00000246 000017de 00000000 f396aa00 003d1249 d0b68140 > d0b68030 f396aa00 003d1249 6d519e00 00000002 c0396434 d8bf8e30 d8bf8e38 > 00000246 d7169ca0 c0270f08 d0b68030 00000001 d0b68030 c0113b25 d8bf8e38 >Call Trace: > [<c0270f08>] __down+0x81/0xdc > [<c026f3ba>] __down_failed+0xa/0x10 > [<e0c91a62>] .text.lock.lock+0x15/0x1b [reiser4] > [<e0c90faf>] longterm_lock_znode+0x5b4/0x7b0 [reiser4] > [<e0cba16a>] cbk_level_lookup+0x8a/0x954 [reiser4] > [<e0cbb186>] traverse_tree+0x752/0xa0d [reiser4] > [<e0cbbbc2>] coord_by_handle+0x781/0x789 [reiser4] > [<e0cbbdb5>] object_lookup+0x1eb/0x230 [reiser4] > [<e0cdb201>] find_file_item+0x18d/0x1b7 [reiser4] > [<e0cdd873>] write_flow+0x208/0x6e1 [reiser4] > [<e0cde208>] write_unix_file+0x3d9/0x5b0 [reiser4] > [<c0147d36>] vfs_write+0x8a/0x133 > [<c0148569>] sys_write+0x3b/0x60 > [<c01029bb>] sysenter_past_esp+0x54/0x75 > >Below are the detailed test I ran. Feel free to ask for more information. > >Reiser4 FS >========== > >Desktop$ cd ~/kernel > >kernel$ df . >Sys. de fich. Tail. Occ. Disp. %Occ. Monté sur >/dev/hda8 925M 825M 101M 90% /home/laurent/kernel > >kernel$ grep hda8 /proc/mounts >/dev/hda8 /home/laurent/kernel reiser4 >rw,nosuid,nodev,atom_max_size=0x7e0c,atom_max_age=0x249f0,atom_min_size=0x100,atom_max_flushers=0x1,cbk_cache_slots=0x10 > 0 0 > >kernel$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.06user 13.95system 1:42.09elapsed 13%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+250minor)pagefaults 0swaps >0.00user 0.00system 1:22.90elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+191minor)pagefaults 0swaps > >kernel$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.08user 14.01system 1:45.57elapsed 13%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+249minor)pagefaults 0swaps >0.00user 0.00system 0:09.78elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+191minor)pagefaults 0swaps > >kernel$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.06user 14.13system 2:18.27elapsed 10%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+251minor)pagefaults 0swaps >0.00user 0.00system 0:08.48elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+190minor)pagefaults 0swaps > >kernel$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.06user 14.27system 1:56.34elapsed 12%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+251minor)pagefaults 0swaps >0.00user 0.00system 0:10.46elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+190minor)pagefaults 0swaps > > >Reiserfs FS >=========== >kernel$ cd > >~$ df . >Sys. de fich. Tail. Occ. Disp. %Occ. Monté sur >/dev/mapper/vglinux1-lvhome > 7,0G 4,8G 2,3G 68% /home >[/dev/mapper/vglinux1-lvhome resides on /dev/hda4] > >~$ grep lvhome /proc/mounts >/dev/vglinux1/lvhome /home reiserfs rw 0 0 > >~$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.04user 1.75system 0:02.05elapsed 87%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+249minor)pagefaults 0swaps >0.00user 0.10system 0:12.93elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+191minor)pagefaults 0swaps > >~$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.04user 1.83system 0:01.98elapsed 94%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+250minor)pagefaults 0swaps >0.00user 0.16system 0:14.45elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+191minor)pagefaults 0swaps > >~$ sync; time dd if=/dev/zero of=toto bs=1k count=102400; time sync >102400+0 enregistrements lus. >102400+0 enregistrements écrits. >0.04user 1.79system 0:01.95elapsed 93%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+250minor)pagefaults 0swaps >0.00user 0.10system 0:13.47elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k >0inputs+0outputs (0major+190minor)pagefaults 0swaps > >~~ >laurent > > > >
