From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: 2.5.33-mm3 dbench hang and 2.5.33 page allocation failures From: Steven Cole In-Reply-To: <3D779C77.39ABD952@zip.com.au> References: <1031246639.2799.68.camel@spc9.esa.lanl.gov> <3D779C77.39ABD952@zip.com.au> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: 05 Sep 2002 12:22:36 -0600 Message-Id: <1031250156.2799.86.camel@spc9.esa.lanl.gov> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org List-ID: On Thu, 2002-09-05 at 12:03, Andrew Morton wrote: > Steven Cole wrote: > > > > I booted 2.5.33-mm3 and ran dbench with increasing > > numbers of clients: 1,2,3,4,6,8,10,12,16,etc. while > > running vmstat -n 1 600 from another terminal. > > > > After about 3 minutes, the output from vmstat stopped, > > and the dbench 16 output stopped. The machine would > > respond to pings, but not to anything else. I had to > > hard-reset the box. Nothing interesting was saved in > > /var/log/messages. I have the output from vmstat if needed. > > That sounds like a race-leading-to-deadlock. Feeding the SYSRQ-T > output into ksymoops is about the only way you have of diagnosing that > I'm afraid. I have CONFIG_MAGIC_SYSRQ=y for 2.5.33-mm3, so I'll reboot and try to get some useful information. > > > The test box is dual p3, 1GB, scsi, ext3 fs. > > Kernels are SMP,_HIGHMEM4G, no PREEMPT, no HIGHPTE. > > > > Earlier this morning, I ran 2.5.33 and the dbench test and got many > > page allocation failure messages before I terminated the test. > > > > Steven > > > > Sep 5 07:20:01 spc5 kernel: dbench: page allocation failure. order:0, mode:0x50 > > Sep 5 07:28:32 spc5 kernel: dbench: page allocation failure. order:0, mode:0x50 > > Presumably, this was when running a lot more than 16 clients? Yep, about 52 clients when those messages started coming in hot and heavy, but they started with fewer clients. I can rerun the test if that threshold is of interest. > > It's just a warning, btw. Allocation failures are expected for GFP_NOIO > allocations. Increasingly so lately, actually. Ok, thanks. But the total hang is something else. I'll try alt-sysrq-t with 2.5.33-mm3 and see what can be determined. Steven -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/