On Tue, Oct 06, 2009 at 04:20:32PM -0400, Alan D. Brunelle wrote: > Coincidentally I was investigating something similar w/ RHEL 5.4 at this > very moment - just wanted to know if that was a common denominator. > > Could you run the attached SystemTap script and send out the output? > [You may have to get `systemtap' though...] Thanks for the excuse to try SystemTap. :) I have some traces, but I don't think the UT case is abnormal. On my desktop at home, I can see btraces such as this, which seem to show it happening often: # btrace /dev/md0 9,0 2 1 0.000000000 11679 P N [flush-9:0] 9,0 2 2 0.000006301 11679 Q W 103873856 + 8 [flush-9:0] 9,0 2 3 0.001946762 0 UT N [swapper] 0 9,0 2 4 0.001964494 290 U N [kblockd/2] 0 9,0 2 5 4.625939573 13087 Q W 103899840 + 8 [firefox-bin] 9,0 2 6 4.635987726 13087 P N [firefox-bin] 9,0 2 7 4.637612451 13087 UT N [firefox-bin] 0 9,0 2 8 4.637670985 290 U N [kblockd/2] 0 9,0 0 1 4.996817219 11679 Q W 85739464 + 8 [flush-9:0] 9,0 0 2 5.005772973 11679 P N [flush-9:0] 9,0 0 3 5.005789934 11679 Q W 92127240 + 8 [flush-9:0] 9,0 0 4 5.012468560 4 UT N [ksoftirqd/0] 0 9,0 0 5 5.012482690 288 U N [kblockd/0] 0 9,0 2 9 6.829559401 13087 Q W 103907504 + 8 [firefox-bin] 9,0 2 10 6.838558733 13087 P N [firefox-bin] 9,0 2 11 6.838560239 13087 Q W 103907512 + 8 [firefox-bin] 9,0 2 12 6.838561798 13087 Q W 103907528 + 8 [firefox-bin] 9,0 2 13 6.838563499 13087 Q W 103907624 + 8 [firefox-bin] 9,0 2 14 6.838564916 13087 Q W 103907664 + 8 [firefox-bin] 9,0 2 15 6.838566357 13087 Q W 103907672 + 8 [firefox-bin] 9,0 2 16 6.841928170 0 UT N [swapper] 0 9,0 2 17 6.841934150 290 U N [kblockd/2] 0 ^CCPU0 (9,0): Reads Queued: 0, 0KiB Writes Queued: 2, 8KiB Read Dispatches: 0, 0KiB Write Dispatches: 0, 0KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 0, 0KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB Read depth: 0 Write depth: 0 IO unplugs: 1 Timer unplugs: 1 CPU2 (9,0): Reads Queued: 0, 0KiB Writes Queued: 8, 32KiB Read Dispatches: 0, 0KiB Write Dispatches: 0, 0KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 0, 0KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB Read depth: 0 Write depth: 0 IO unplugs: 3 Timer unplugs: 3 Total (9,0): Reads Queued: 0, 0KiB Writes Queued: 10, 40KiB Read Dispatches: 0, 0KiB Write Dispatches: 0, 0KiB Reads Requeued: 0 Writes Requeued: 0 Reads Completed: 0, 0KiB Writes Completed: 0, 0KiB Read Merges: 0, 0KiB Write Merges: 0, 0KiB IO unplugs: 4 Timer unplugs: 4 Throughput (R/W): 0KiB/s / 0KiB/s Events (9,0): 22 entries Skips: 0 forward (0 - 0.0%) This is on ext3 via MD raid 1, 0eca52a92735f43462165efe00a7e394345fb38e kernel version aka "2.6.32rc3". Simon- -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
