Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: page allocation failures with 2.6.5 on s390 | Date | Sun, 25 Apr 2004 12:49:30 +0200 |
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Bastian Blank <bastian@waldi.eu.org> wrote: > On Sat, Apr 24, 2004 at 01:21:59PM -0700, Andrew Morton wrote: > > Bastian Blank <bastian@waldi.eu.org> wrote: > > > Today I see the following error message in the logs of two machines > > > with 2.6.5 on s390, both 31 and 64 bit. > > This is pretty much unavoidable - the kernel is looking for four > > physically-contiguous free pages at interrupt time, and there aren't any. > > You can reduce its frequency by increasing /proc/sys/vm/min_free_kbytes. > > The best fix would be to alter the driver to use order-0 pages if that's > > possible. > > The pages are 4KiB large, so it allocates 16KiB at once. So the problem is = > rather clear: > | 3: eth0: <BROADCAST,MULTICAST,UP> mtu 8192 qdisc pfifo_fast qlen 100
Is this the vanilla kernel? Note that 2.6.6-rc2 contains a different qeth driver (the same that you get if you apply the 2.6.5 patches from http://www10.software.ibm.com/developerworks/opensource/linux390), which might help you here. Getting the mtu size below 7500 could also give you relief if that causes order-1 allocations instead of order-2
> I'm currently not sure if this was the problem causing D process. I > reread the logs and found the following: > | Unable to handle kernel pointer dereference at virtual kernel address 000= > 0000000000000
Since this is the pdflush thread that was killed, it's just a matter of time until everything hangs.
> | Oops: 0004 [#1] > | CPU: 0 Not tainted > | Process pdflush (pid: 33, task: 000000000fa58e90, ksp: 000000000fa53b98) > | Krnl PSW : 0700200180000000 00000000001022b0 (nfs3_request_init+0x34/0x50) > | Krnl GPRS: 0000000000000000 0000000000000001 0000000000000000 0000000000000028 > | 0000000000000001 0000000000000000 0000000000001000 000000000672f548 > | 0000000000403620 000000000dceb600 0000000000000000 0000000000823020 > | 00000000061bfd00 000000000029afb8 00000000001022a0 000000000fa53178 > | Krnl Code: ba 54 30 00 a7 44 ff fc e3 20 c0 30 00 24 e3 40 f1 10 00 04
ba 54 30 00 means 'cs %r5,%r4,0(%r3)' and accessing %r3 failed (it contains 0x28, as you can see).
In the corresponding code (from fs/nfs/nfs3proc.c), you can see what this means: void nfs3_request_init(struct nfs_page *req, struct file *filp) { req->wb_cred = get_rpccred(nfs_cred(req->wb_inode, filp)); } nfs_cread(...) returns NULL, and get_rpccred(...) accesses this at offset 0x28 with atomic_inc (aka cs). Someone familiar with nfs needs to look into how this can happen, but it does not appear to be s390 specific.
> | Call Trace: > | [nfs_create_request+216/312] nfs_create_request+0xd8/0x138 > | [nfs_update_request+678/1236] nfs_update_request+0x2a6/0x4d4 > | [nfs_writepage_async+44/264] nfs_writepage_async+0x2c/0x108 > | [nfs_writepage+466/476] nfs_writepage+0x1d2/0x1dc > | [mpage_writepages+796/1084] mpage_writepages+0x31c/0x43c > | [nfs_writepages+56/196] nfs_writepages+0x38/0xc4 > | [do_writepages+46/76] do_writepages+0x2e/0x4c > | [__sync_single_inode+200/744] __sync_single_inode+0xc8/0x2e8 > | [__writeback_single_inode+246/260] __writeback_single_inode+0xf6/0x104 > | [sync_sb_inodes+472/792] sync_sb_inodes+0x1d8/0x318 > | [writeback_inodes+144/248] writeback_inodes+0x90/0xf8 > | [wb_kupdate+182/324] wb_kupdate+0xb6/0x144 > | [__pdflush+430/700] __pdflush+0x1ae/0x2bc > | [pdflush+46/60] pdflush+0x2e/0x3c > | [kthread+228/236] kthread+0xe4/0xec > | [kernel_thread_starter+20/28] kernel_thread_starter+0x14/0x1c
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