Messages in this thread | | | Subject | Re: [Problem] System hang when I run pounder and syscall test on kernel 2.6.18-rc5 | From | Shu Qing Yang <> | Date | Mon, 11 Sep 2006 10:09:56 +0800 |
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Andrew Morton <akpm@osdl.org> wrote on 2006-09-09 00:52:41:
> On Fri, 8 Sep 2006 19:36:40 +0800 > Shu Qing Yang <yangshuq@cn.ibm.com> wrote: > > > Andrew Morton <akpm@osdl.org> wrote on 2006-09-08 10:14:34: > > > > > On Thu, 7 Sep 2006 12:35:09 +0800 > > > Shu Qing Yang <yangshuq@cn.ibm.com> wrote: > > > > > > > Problem description: > > > > I run pounder, scsi_debug on a machine. Then start 200 random > > syscall > > > > test > > > > simultaneously. Tens of minutes later, the system hang. > > > > > > What is "pounder" and from where can it be obtained? > > > > > Thanks for your reply. > > > > Pounder is part of ltp and locate in LTPROOT/testcases/pounder21. > > It is a suit of test cases including mem_alloc, random_syscall, bonnie++, > > etc. > > OK, thanks. > > > > Running two tests at the same time complicates things. The next step > > > should be to determine whether it is reproducible. If it is, then see > > if > > > it is reproducible with just one test running (presumably pounder?) > > > > > Running multiple cases simultaneously is to stress kernel more. And > > because of > > lack of machine resource I have no chance to reproduce it. > > > > > It would be helpful to provide sufficient information to give others a > > > chance of reproducing it: amount of memory, method for configuring the > > > scsi-debug "disks", method for invoking pounder, etc. > > > > > The machine belongs to IBM p-Series with power5+ cpu and 2GB memory. > > Run LTPROOT/testscript/ltp-scsi_debug.sh and > > LTPROOT/testscript/pounder21/pounder directly. > > No extra parameters. The command to load scsi_debug module is: > > modprobe scsi_debug max_luns=2 num_tgts=2 add_host=2 dev_size_mb=20 > > > > ... > > > > I can not excute sysrq command now. But I can get memory allocation > > information from xmon, > > which indicates your guess may be right. > > > > 1:mon> mi > > Mem-info: > > DMA per-cpu: > > cpu 0 hot: high 6, batch 1 used:5 > > cpu 0 cold: high 2, batch 1 used:1 > > cpu 1 hot: high 6, batch 1 used:5 > > cpu 1 cold: high 2, batch 1 used:1 > > cpu 2 hot: high 6, batch 1 used:5 > > cpu 2 cold: high 2, batch 1 used:1 > > cpu 3 hot: high 6, batch 1 used:3 > > cpu 3 cold: high 2, batch 1 used:1 > > cpu 4 hot: high 6, batch 1 used:5 > > cpu 4 cold: high 2, batch 1 used:1 > > cpu 5 hot: high 6, batch 1 used:4 > > cpu 5 cold: high 2, batch 1 used:0 > > DMA32 per-cpu: empty > > Normal per-cpu: empty > > HighMem per-cpu: empty > > Free pages: 6976kB (0kB HighMem) > > Active:6141 inactive:11012 dirty:4742 writeback:0 unstable:0 free:109 > > slab:11925 mapped:7 pagetables:7061 > > DMA free:6976kB min:5760kB low:7168kB high:8640kB active:393024kB > > inactive:704768kB present:2097152kB pages_scanned:5172 all_unreclaimable? > > no > > lowmem_reserve[]: 0 0 0 0 > > DMA32 free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB > > present:0kB pages_scanned:0 all_unreclaimable? no > > lowmem_reserve[]: 0 0 0 0 > > Normal free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB > > present:0kB pages_scanned:0 all_unreclaimable? no > > lowmem_reserve[]: 0 0 0 0 > > HighMem free:0kB min:2048kB low:2048kB high:2048kB active:0kB inactive:0kB > > present:0kB pages_scanned:0 all_unreclaimable? no > > lowmem_reserve[]: 0 0 0 0 > > DMA: 19*64kB 1*128kB 2*256kB 0*512kB 1*1024kB 0*2048kB 1*4096kB 0*8192kB > > 0*16384kB = 6976kB > > DMA32: empty > > Normal: empty > > HighMem: empty > > Swap cache: add 439156, delete 439156, find 50391/101032, race 26+79 > > Free swap = 0kB > > Total swap = 855552kB > > Free swap: 0kB > > 32768 pages of RAM > > 408 reserved pages > > 6834 pages shared > > 0 pages swap cached > > So we ran out of memory and we ran out of swap. > > Possibly what has happened here is that the machine is doing a huge amount > of work scanning pages and pretty soon it will enter the oom-killer to kill > some userspace process. But before that happened, the softlockup detector > triggered. > > But the machine _should_ have recovered. If it hung for more than a few > seconds then that's bad behaviour. If it hung for more than a few minutes > then that should be considered a bug. If it hung for ever then that's > definitely a bug. > > Do you recall approximately how long the machine spent in this state? System stayed in hang ten minutes at least. Then I forced it into xmon via sysrq. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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