Re: 2.6.21-rc3: /proc broken
On Friday 09 March 2007 19:53, Russell King wrote: > On Fri, Mar 09, 2007 at 08:56:44AM +1100, Con Kolivas wrote: > > I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt > > and chose all the defaults. Then building your fat config with -rc3, 'ps' > > hangs on qemu for almost 30 seconds and then at last produces a broken > > output > > Let me guess - you have either a serial console or something like that > and you're running these commands over said serial console? > > Or you have console directed to both a serial port and the VT and you're > capturing this off the VT using gpm. > > Either way, "serial8250: too much work for irq4" is a printk which will > be displayed by the kernel when it's unable to clear down work for the > serial port within 256 loops or so of the interrupt handler; it's a > protection against the box locking up. > > It not actually contained in any of the files. Thank you very much for taking the time to explain it to me and I apologise for the false positive. It's very much due to running qemu directing everything to the serial console which is just as you say. Allowing qemu to output to graphic fixes the error. Unfortunately that also makes akpm's oops go away so I can't really reproduce it now. Perhaps the bug occurs due to interrupts being disabled for an extended time; it gives me something to look at now. Thanks! -- -ck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: 2.6.21-rc3: /proc broken
On Fri, Mar 09, 2007 at 08:56:44AM +1100, Con Kolivas wrote: > I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and > chose all the defaults. Then building your fat config with -rc3, 'ps' hangs > on qemu for almost 30 seconds and then at last produces a broken output Let me guess - you have either a serial console or something like that and you're running these commands over said serial console? Or you have console directed to both a serial port and the VT and you're capturing this off the VT using gpm. Either way, "serial8250: too much work for irq4" is a printk which will be displayed by the kernel when it's unable to clear down work for the serial port within 256 loops or so of the interrupt handler; it's a protection against the box locking up. It not actually contained in any of the files. -- Russell King Linux kernel2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: 2.6.21-rc3: /proc broken
On Fri, Mar 09, 2007 at 08:56:44AM +1100, Con Kolivas wrote: I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and chose all the defaults. Then building your fat config with -rc3, 'ps' hangs on qemu for almost 30 seconds and then at last produces a broken output Let me guess - you have either a serial console or something like that and you're running these commands over said serial console? Or you have console directed to both a serial port and the VT and you're capturing this off the VT using gpm. Either way, serial8250: too much work for irq4 is a printk which will be displayed by the kernel when it's unable to clear down work for the serial port within 256 loops or so of the interrupt handler; it's a protection against the box locking up. It not actually contained in any of the files. -- Russell King Linux kernel2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: 2.6.21-rc3: /proc broken
On Friday 09 March 2007 19:53, Russell King wrote: On Fri, Mar 09, 2007 at 08:56:44AM +1100, Con Kolivas wrote: I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and chose all the defaults. Then building your fat config with -rc3, 'ps' hangs on qemu for almost 30 seconds and then at last produces a broken output Let me guess - you have either a serial console or something like that and you're running these commands over said serial console? Or you have console directed to both a serial port and the VT and you're capturing this off the VT using gpm. Either way, serial8250: too much work for irq4 is a printk which will be displayed by the kernel when it's unable to clear down work for the serial port within 256 loops or so of the interrupt handler; it's a protection against the box locking up. It not actually contained in any of the files. Thank you very much for taking the time to explain it to me and I apologise for the false positive. It's very much due to running qemu directing everything to the serial console which is just as you say. Allowing qemu to output to graphic fixes the error. Unfortunately that also makes akpm's oops go away so I can't really reproduce it now. Perhaps the bug occurs due to interrupts being disabled for an extended time; it gives me something to look at now. Thanks! -- -ck - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
2.6.21-rc3: /proc broken
On Friday 09 March 2007 01:52, Con Kolivas wrote: > On Thursday 08 March 2007 15:19, Andrew Morton wrote: > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc3/ > >2. 6.21-rc3-mm2/ > > > > - This is the same as 2.6.21-rc3-mm1, except Con's CPU scheduler changes > > were dropped. > So on qemu I can reproduce the oops you're getting with your config (make > oldconfig all default on top of your config), but I'm getting other > wonderful related problems too on rc3-mm2. On qemu -mm1 boots mostly > without error and then crashes nicely when I type 'ps' with a long pause > for about twenty seconds and then a combination of soft lockups, bitmap > errors, and eventually hits the BUG_ON I put in bitmap_error(). However, > -mm2 also vomits on typing 'ps'. > > It pauses and then spits out (fun lines selected from ps output): > > 7 ?serial8250: too much work for irq4 > 00:00:00 watchdog/1 >88 ?00:00:0serial8250: too much work for irq4 > 0 cqueue/1 > 137 ?00:00serial8250: too much work for irq4 > > :00 aio/0 > > Checking a few /proc files I see that "serial83250" info littered > throughout /proc/stat as well. -mm2 does not oops but the proc output is > variously corrupted. > > Interestingly if I don't type 'ps' in the -mm1 qemu it runs fine with no > sign of a bug... In summary, here I can only reproduce your big fat oops by > it being triggered by some corruption elsewhere on this config related to > /proc breakage that I haven't managed to track down. I checked the > broken-out patches to see which touched /proc and it was oh, most of them. > I tried on rc3 and had the same thing happen. I haven't tried rc3 without > rsdl (your config takes too darn long to build!). /proc appears broken on vanilla -rc3 as well. I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and chose all the defaults. Then building your fat config with -rc3, 'ps' hangs on qemu for almost 30 seconds and then at last produces a broken output PID TTY TIME CMD 1 ?00:00:00 init 2 ?00:00:00 migration/0 3 ?00:00:00 ksoftirqd/0 4 ?00:00:00 watchdog/0 5 ?00:00:00 migration/1 6 ?00:00:00 ksoftirqd/1 7 ?serial8250: too much work for irq4 00:00:00 watchdog/1 8 ?00:00:00 events/0 9 ?00:00:00 events/1 10 ?00:00:00 khelper 11 ?00:00:00 kthread 52 ?00:00:00 kblockd/0 53 ?00:00:00 kblockd/1 54 ?00:00:00 kacpid 87 ?00:00:00 cqueue/0 88 ?00:00:00 cqueue/1 89 ?00:00:00 ata/0 90 ?00:00:00 ata/1 91 ?00:00:00 ata_aux 92 ?00:00:00 ksuspend_usbd 95 ?00:00:00 khubd 97 ?00:00:00 kseriod 133 ?00:00:00 pdflush 134 ?00:00:00 pdflush 135 ?00:00:00 kserial8250: too much work for irq4 swapd0 136 ?00:00:00 aio/0 137 ?00:00:00 aio/1 287 ?00:00:00 kpsmoused 311 ?00:00:00 sh 312 ?00:00:00 ps It's random where this happens too. Sometimes it goes away, other times it's different tasks, and it happens to /proc/stat too -- -ck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
2.6.21-rc3: /proc broken
On Friday 09 March 2007 01:52, Con Kolivas wrote: On Thursday 08 March 2007 15:19, Andrew Morton wrote: ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc3/ 2. 6.21-rc3-mm2/ - This is the same as 2.6.21-rc3-mm1, except Con's CPU scheduler changes were dropped. So on qemu I can reproduce the oops you're getting with your config (make oldconfig all default on top of your config), but I'm getting other wonderful related problems too on rc3-mm2. On qemu -mm1 boots mostly without error and then crashes nicely when I type 'ps' with a long pause for about twenty seconds and then a combination of soft lockups, bitmap errors, and eventually hits the BUG_ON I put in bitmap_error(). However, -mm2 also vomits on typing 'ps'. It pauses and then spits out (fun lines selected from ps output): 7 ?serial8250: too much work for irq4 00:00:00 watchdog/1 88 ?00:00:0serial8250: too much work for irq4 0 cqueue/1 137 ?00:00serial8250: too much work for irq4 :00 aio/0 Checking a few /proc files I see that serial83250 info littered throughout /proc/stat as well. -mm2 does not oops but the proc output is variously corrupted. Interestingly if I don't type 'ps' in the -mm1 qemu it runs fine with no sign of a bug... In summary, here I can only reproduce your big fat oops by it being triggered by some corruption elsewhere on this config related to /proc breakage that I haven't managed to track down. I checked the broken-out patches to see which touched /proc and it was oh, most of them. I tried on rc3 and had the same thing happen. I haven't tried rc3 without rsdl (your config takes too darn long to build!). /proc appears broken on vanilla -rc3 as well. I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and chose all the defaults. Then building your fat config with -rc3, 'ps' hangs on qemu for almost 30 seconds and then at last produces a broken output PID TTY TIME CMD 1 ?00:00:00 init 2 ?00:00:00 migration/0 3 ?00:00:00 ksoftirqd/0 4 ?00:00:00 watchdog/0 5 ?00:00:00 migration/1 6 ?00:00:00 ksoftirqd/1 7 ?serial8250: too much work for irq4 00:00:00 watchdog/1 8 ?00:00:00 events/0 9 ?00:00:00 events/1 10 ?00:00:00 khelper 11 ?00:00:00 kthread 52 ?00:00:00 kblockd/0 53 ?00:00:00 kblockd/1 54 ?00:00:00 kacpid 87 ?00:00:00 cqueue/0 88 ?00:00:00 cqueue/1 89 ?00:00:00 ata/0 90 ?00:00:00 ata/1 91 ?00:00:00 ata_aux 92 ?00:00:00 ksuspend_usbd 95 ?00:00:00 khubd 97 ?00:00:00 kseriod 133 ?00:00:00 pdflush 134 ?00:00:00 pdflush 135 ?00:00:00 kserial8250: too much work for irq4 swapd0 136 ?00:00:00 aio/0 137 ?00:00:00 aio/1 287 ?00:00:00 kpsmoused 311 ?00:00:00 sh 312 ?00:00:00 ps It's random where this happens too. Sometimes it goes away, other times it's different tasks, and it happens to /proc/stat too -- -ck - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
