On Fri 13-12-13 14:01:34, Toralf Förster wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > On 12/13/2013 11:51 AM, Richard Weinberger wrote: > > On Fri, Dec 13, 2013 at 10:52 AM, Toralf Förster <toralf.foerster@xxxxxx> wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- > >> Hash: SHA256 > >> > >> On 12/11/2013 09:26 PM, Jan Kara wrote: > >>> Thanks! So this works more or less as expected - trinity issued a > >>> read at absurdly high offset so we created pagecache page a that > >>> offset and tried to read data into it. That failed. We left the > >>> page in the pagecache where it was for reclaim to reclaim it when > >>> free pages are needed. Everything works as designed except we could > >>> possibly argue that it's not the most efficient way to use > >>> pages... > >>> > >>> Patch 'vfs: fix a bug when we do some dio reads with append dio > >>> writes' (http://www.spinics.net/lists/linux-fsdevel/msg70899.html) > >>> should actually change the situation and we won't unnecessarily > >>> cache these pages. > >>> > >> confirmed - applied to latest git tree of Linus I helps. > > > > Good to know! :-) > > > > OTOH - there's seems to be more places for an improvement - now trinity > often runs hours w/o problem (before it runs within a rather short time > into such issues). > > But today I got another case (I did not patched the source files except > the mentioned patch by Jan Kara) where the trinity call cycles since 2 > hours w/o any progress. But fortunately the system is still responsive, > ssh works and I can shutdown that virtual machine smoothly, furthermore > all local and remote file systems can be unounted cleanly - so that patch > is a big improvement). OK, that is indeed strange. Can you step through find_get_pages() in gdb to see where exactly are we looping? From the traces below the argument values look somewhat unreliable so it's not clear to me what is exactly happening. Honza > tfoerste@n22 ~/devel/github/bingo $ date; sudo gdb /home/tfoerste/devel/linux/linux 9776 -n -batch -ex 'bt' > Fri Dec 13 13:54:33 CET 2013 > find_get_pages (mapping=0x45182810, start=0, nr_pages=14, pages=0x0) at mm/filemap.c:885 > 885 } > #0 find_get_pages (mapping=0x45182810, start=0, nr_pages=14, pages=0x0) at mm/filemap.c:885 > #1 0x080d669a in pagevec_lookup (pvec=0x40607d40, mapping=0x0, start=0, nr_pages=0) at mm/swap.c:937 > #2 0x080d6a9a in truncate_inode_pages_range (mapping=0x45182810, lstart=0, lend=-1) at mm/truncate.c:241 > #3 0x080d6e3f in truncate_inode_pages (mapping=0x0, lstart=0) at mm/truncate.c:358 > #4 0x0818c2d2 in ext4_evict_inode (inode=0x45182758) at fs/ext4/inode.c:228 > #5 0x0811b5ff in evict (inode=0x45182758) at fs/inode.c:549 > #6 0x0811c0ed in iput_final (inode=<optimized out>) at fs/inode.c:1419 > #7 iput (inode=0x45182758) at fs/inode.c:1437 > #8 0x08112056 in do_unlinkat (dfd=5, pathname=0x8065d84 <register_lines+276> "") at fs/namei.c:3718 > #9 0x081121c5 in SYSC_unlinkat (flag=<optimized out>, pathname=<optimized out>, dfd=<optimized out>) at fs/namei.c:3754 > #10 SyS_unlinkat (dfd=5, pathname=134634884, flag=0) at fs/namei.c:3746 > #11 0x08062a94 in handle_syscall (r=0x473b59cc) at arch/um/kernel/skas/syscall.c:35 > #12 0x080750f5 in handle_trap (local_using_sysemu=<optimized out>, regs=<optimized out>, pid=<optimized out>) at arch/um/os-Linux/skas/process.c:198 > #13 userspace (regs=0x473b59cc) at arch/um/os-Linux/skas/process.c:431 > #14 0x0805f750 in fork_handler () at arch/um/kernel/process.c:149 > #15 0x5a5a5a5a in ?? () > > > tfoerste@n22 ~/devel/github/bingo $ date; sudo gdb /home/tfoerste/devel/linux/linux 9776 -n -batch -ex 'bt' > Fri Dec 13 13:54:47 CET 2013 > radix_tree_next_chunk (root=0x3f, iter=0x40607cdc, flags=6) at lib/radix-tree.c:773 > 773 index &= ~((RADIX_TREE_MAP_SIZE << shift) - 1); > #0 radix_tree_next_chunk (root=0x3f, iter=0x40607cdc, flags=6) at lib/radix-tree.c:773 > #1 0x080cc88e in find_get_pages (mapping=0x45182810, start=0, nr_pages=14, pages=0x6) at mm/filemap.c:844 > #2 0x080d669a in pagevec_lookup (pvec=0x40607d40, mapping=0x3f, start=63, nr_pages=63) at mm/swap.c:937 > #3 0x080d6a9a in truncate_inode_pages_range (mapping=0x45182810, lstart=0, lend=-1) at mm/truncate.c:241 > #4 0x080d6e3f in truncate_inode_pages (mapping=0x3f, lstart=25769803839) at mm/truncate.c:358 > #5 0x0818c2d2 in ext4_evict_inode (inode=0x45182758) at fs/ext4/inode.c:228 > #6 0x0811b5ff in evict (inode=0x45182758) at fs/inode.c:549 > #7 0x0811c0ed in iput_final (inode=<optimized out>) at fs/inode.c:1419 > #8 iput (inode=0x45182758) at fs/inode.c:1437 > #9 0x08112056 in do_unlinkat (dfd=5, pathname=0x8065d84 <register_lines+276> "") at fs/namei.c:3718 > #10 0x081121c5 in SYSC_unlinkat (flag=<optimized out>, pathname=<optimized out>, dfd=<optimized out>) at fs/namei.c:3754 > #11 SyS_unlinkat (dfd=5, pathname=134634884, flag=0) at fs/namei.c:3746 > #12 0x08062a94 in handle_syscall (r=0x473b59cc) at arch/um/kernel/skas/syscall.c:35 > #13 0x080750f5 in handle_trap (local_using_sysemu=<optimized out>, regs=<optimized out>, pid=<optimized out>) at arch/um/os-Linux/skas/process.c:198 > #14 userspace (regs=0x473b59cc) at arch/um/os-Linux/skas/process.c:431 > #15 0x0805f750 in fork_handler () at arch/um/kernel/process.c:149 > #16 0x5a5a5a5a in ?? () > > > tfoerste@n22 ~/devel/github/bingo $ date; sudo gdb /home/tfoerste/devel/linux/linux 9776 -n -batch -ex 'bt' > Fri Dec 13 13:57:16 CET 2013 > radix_tree_next_chunk (root=0x10, iter=0x40607cdc, flags=6) at lib/radix-tree.c:769 > 769 while (++offset < RADIX_TREE_MAP_SIZE) { > #0 radix_tree_next_chunk (root=0x10, iter=0x40607cdc, flags=6) at lib/radix-tree.c:769 > #1 0x080cc88e in find_get_pages (mapping=0x45182810, start=0, nr_pages=14, pages=0x6) at mm/filemap.c:844 > #2 0x080d669a in pagevec_lookup (pvec=0x40607d40, mapping=0x10, start=16, nr_pages=16) at mm/swap.c:937 > #3 0x080d6a9a in truncate_inode_pages_range (mapping=0x45182810, lstart=0, lend=-1) at mm/truncate.c:241 > #4 0x080d6e3f in truncate_inode_pages (mapping=0x10, lstart=25769803792) at mm/truncate.c:358 > #5 0x0818c2d2 in ext4_evict_inode (inode=0x45182758) at fs/ext4/inode.c:228 > #6 0x0811b5ff in evict (inode=0x45182758) at fs/inode.c:549 > #7 0x0811c0ed in iput_final (inode=<optimized out>) at fs/inode.c:1419 > #8 iput (inode=0x45182758) at fs/inode.c:1437 > #9 0x08112056 in do_unlinkat (dfd=5, pathname=0x8065d84 <register_lines+276> "") at fs/namei.c:3718 > #10 0x081121c5 in SYSC_unlinkat (flag=<optimized out>, pathname=<optimized out>, dfd=<optimized out>) at fs/namei.c:3754 > #11 SyS_unlinkat (dfd=5, pathname=134634884, flag=0) at fs/namei.c:3746 > #12 0x08062a94 in handle_syscall (r=0x473b59cc) at arch/um/kernel/skas/syscall.c:35 > #13 0x080750f5 in handle_trap (local_using_sysemu=<optimized out>, regs=<optimized out>, pid=<optimized out>) at arch/um/os-Linux/skas/process.c:198 > #14 userspace (regs=0x473b59cc) at arch/um/os-Linux/skas/process.c:431 > #15 0x0805f750 in fork_handler () at arch/um/kernel/process.c:149 > #16 0x5a5a5a5a in ?? () > > - -- > MfG/Sincerely > Toralf Förster > pgp finger print:1A37 6F99 4A9D 026F 13E2 4DCF C4EA CDDE 0076 E94E > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v2.0.22 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iF4EAREIAAYFAlKrBS0ACgkQxOrN3gB26U4bRgD/U/5sIELFBZUTeEgfM9eJBnxh > PhdMMBTTJHoB3v9z70YA/iEZzD9L30vVSWqYrybOWNPYwDR1i67F41nUemmPczqu > =u/iT > -----END PGP SIGNATURE----- -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>