On Wed, May 28 2008, James Bottomley wrote: > On Wed, 2008-05-28 at 10:58 -0700, Andrew Morton wrote: > > On Wed, 28 May 2008 03:52:37 -0700 (PDT) bugme-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=10810 > > > > > > Summary: Performance regression on DAC960 and kernel 2.6.24+ > > > Product: IO/Storage > > > Version: 2.5 > > > KernelVersion: 2.6.24, 2.6.25 > > > Platform: All > > > OS/Version: Linux > > > Tree: Mainline > > > Status: NEW > > > Severity: high > > > Priority: P1 > > > Component: Block Layer > > > AssignedTo: axboe@xxxxxxxxx > > > ReportedBy: alex@xxxxxxxxxx > > > > > > > > > Latest working kernel version: > > > 2.6.23 > > > > > > Earliest failing kernel version: > > > 2.6.24 > > > > > > Distribution: > > > Debian > > > > > > Hardware Environment: > > > 00:00.0 RAM memory: nVidia Corporation C51 Host Bridge (rev a2) > > > 00:00.1 RAM memory: nVidia Corporation C51 Memory Controller 0 (rev a2) > > > 00:00.2 RAM memory: nVidia Corporation C51 Memory Controller 1 (rev a2) > > > 00:00.3 RAM memory: nVidia Corporation C51 Memory Controller 5 (rev a2) > > > 00:00.4 RAM memory: nVidia Corporation C51 Memory Controller 4 (rev a2) > > > 00:00.5 RAM memory: nVidia Corporation C51 Host Bridge (rev a2) > > > 00:00.6 RAM memory: nVidia Corporation C51 Memory Controller 3 (rev a2) > > > 00:00.7 RAM memory: nVidia Corporation C51 Memory Controller 2 (rev a2) > > > 00:02.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) > > > 00:03.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) > > > 00:04.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1) > > > 00:05.0 VGA compatible controller: nVidia Corporation C51G [GeForce 6100] (rev > > > a2) > > > 00:09.0 RAM memory: nVidia Corporation MCP51 Host Bridge (rev a2) > > > 00:0a.0 ISA bridge: nVidia Corporation MCP51 LPC Bridge (rev a2) > > > 00:0a.1 SMBus: nVidia Corporation MCP51 SMBus (rev a2) > > > 00:0b.0 USB Controller: nVidia Corporation MCP51 USB Controller (rev a2) > > > 00:0b.1 USB Controller: nVidia Corporation MCP51 USB Controller (rev a2) > > > 00:0d.0 IDE interface: nVidia Corporation MCP51 IDE (rev a1) > > > 00:0e.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller (rev a1) > > > 00:10.0 PCI bridge: nVidia Corporation MCP51 PCI Bridge (rev a2) > > > 00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a1) > > > 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] > > > HyperTransport Technology Configuration > > > 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address > > > Map > > > 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM > > > Controller > > > 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] > > > Miscellaneous Control > > > 04:08.0 RAID bus controller: Mylex Corporation AcceleRAID 352/170/160 support > > > Device (rev 02) > > > > > > Software Environment: > > > Debian Lenny 64bit > > > > > > Problem Description: > > > I/O Access is very slow on some condition, for example samba users can't write > > > more than a few KB/sec on the shares. > > > Also tomcat is veeeery slow to startup (at least 3 times the normal time). > > > > > > Steps to reproduce: > > > Simply boot with the new kernel > > > > Oh dear. > > > > There's been only one change to DAC960.c in that timeframe: > > > > commit 0156c2547e92df559d5592aad9535838ef459615 > > Author: Kiyoshi Ueda <k-ueda@xxxxxxxxxxxxx> > > Date: Tue Dec 11 17:43:15 2007 -0500 > > > > blk_end_request: changing DAC960 (take 4) > > > > This patch converts DAC960 to use blk_end_request interfaces. > > Related 'UpToDate' arguments are converted to 'Error'. > > > > Signed-off-by: Kiyoshi Ueda <k-ueda@xxxxxxxxxxxxx> > > Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx> > > Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx> > > > > :100644 100644 9030c37... cd03473... M drivers/block/DAC960.c > > > > commit 117636092a87a28a013a4acb5de5492645ed620f > > Author: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > > Date: Tue Oct 23 20:42:11 2007 +0200 > > > > [PATCH] Fix breakage after SG cleanups > > > > and I don't see how it could cause this. The breakage is probably > > external to the driver. > > > > I don't know what it could be and I don't know anyone who can be asked > > to look into it. > > > > If you have time, the only way I can think of getting to the bottom of > > this is if you were to run a git bisection search as per > > http://www.kernel.org/doc/local/git-quick.html. Sorry. > > Well, the DAC960 is very old. It has a trick we escaped from in SCSI > where if it gets an error in the request it resubmits it a sector at a > time. It sounds very much like it's doing that for every request if the > I/O speed is down to a few k/s. > > So, could you try this patch? It won't fix anything, but if the message > spews all over the console, we know the 1 sector at a time retry is > causing the problems. If not we'll try to think of something else ... A bit unlikely, me thinks... Anyway, a blktrace dump of some IO would show what is going on. I'm assuming the problem is persistent across IO schedulers? -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
