Hello,
I have read some previous threads about kupdated consuming 99% of CPU under
intense disk I/O in kernel 2.4.x on the archives of this list (April 2001),
but have yet to find any suggestions or fixes. I am currently experiencing
the same issue and was wondering if anyone has any thoughts or suggestions
on the issue. I am not subscribed to the list so would you please CC: me
directly on any responses? Thank you.
The issue that I am having is that when there is a heavy amount a disk I/O,
the box becomes slightly unresponsive and kupdated is using 99.9% in 'top.'
Sometimes the box appears to totally lock up. If one waits several seconds
to a couple of minutes the system appears to 'unlock' and runs sluggishly
for a while. This cycle will repeat itself until the I/O subsides.
The issue appears in kernel 2.4.14 compiled directly from source from
kernel.org with no patches. These problems manifest themselves with only
one user doing heavy disk I/O. The normal user load on the box can run
between 350-450 users so this behavior would be unacceptable because the
application that is being run is interactive. With 450 users, and the same
process running on a 2.2 kernel the performance of the box is great, with
only a very slightly noticeable slow down.
I am running the Informix database UniVerse version 9.6.2.4 on a 4 processor
700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled by a PERC
2/DC RAID card with 128MB on-board cache (megaraid driver compiled directly
in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in a RAID5
configuration. The box has 4GB RAM, but is only using 2GB due to the move
back to the 2.2 kernel.
If you need any more detailed info, please let me know. Any help on this
problem would be immensely appreciated. Thanks in advance.
Regards,
Andrew Rechenberg
Network Team, Sherman Financial Group
[email protected]
Phone: 513.677.7809
Fax: 513.677.7838
I have to find time to down the box because it's production, but as soon as
I do I'll post the numbers here.
Thanks for your help.
Regards,
Andy.
> Could you please guys try to reproduce the problem with kernel profiling
> turned on and send us the output of readprofile?
> This way we can know which function is using more CPU time, thus we can
> identify the problem.
On Wed, 14 Nov 2001, John McCutchan wrote:
> Hi,
>
> I also have the exact same behaviour when running mkisofs. During the
> creation of the ISO the interactive feel is sluggish and after mkisofs
> is complete the box is sluggish and appears to lock up. During
> this sluggish period there is alot of disk activity. This is under
> 2.4.14
>
> John
> On Wed, Nov 14, 2001 at 06:01:23PM -0500, Rechenberg, Andrew wrote:
> > Hello,
> >
> > I have read some previous threads about kupdated consuming 99% of CPU
under
> > intense disk I/O in kernel 2.4.x on the archives of linux-kernel (April
> > 2001), and some issues about I/O problems on linux-mm, but have yet to
find
> > any suggestions or fixes. I am currently experiencing the same issue
and
> > was wondering if anyone has any thoughts or suggestions on the issue. I
am
> > not subscribed to the list so would you please CC: me directly on any
> > responses? I can also check out the archives at theaimsgroup.com if a
CC:
> > would not be appropriate. Thank you.
> >
> > The issue that I am having is that when there is a heavy amount a disk
I/O,
> > the box becomes slightly unresponsive and kupdated is using 99.9% in
'top.'
> > Sometimes the box appears to totally lock up. If one waits several
seconds
> > to a couple of minutes the system appears to 'unlock' and runs
sluggishly
> > for a while. This cycle will repeat itself until the I/O subsides. The
> > memory usage goes up to the full capacity of the box and then about 10MB
of
> > swap is used while this problem is occurring. Memory and swap does not
get
> > relinquished afer the incident.
> >
> > The issue appears in kernel 2.4.14 compiled directly from source from
> > kernel.org with no patches. These problems manifest themselves with
only
> > one user doing heavy disk I/O. The normal user load on the box can run
> > between 350-450 users so this behavior would be unacceptable because the
> > application that is being run is interactive. With 450 users, and the
same
> > process running on a 2.2.20 kernel the performance of the box is great,
with
> > only a very slightly noticeable slow down.
> >
> > I am running the Informix database UniVerse version 9.6.2.4 on a 4
processor
> > 700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled by a
PERC
> > 2/DC RAID card with 128MB on-board cache (megaraid driver compiled
directly
> > in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in a
RAID5
> > configuration. The box has 4GB RAM, but is only using 2GB due to the
move
> > back to the 2.2 kernel. The only kernel paramters that have been
modified
> > are in /proc/sys/kernel/sem. All filesystems are ext2.
> >
> > If you need any more detailed info, please let me know. Any help on
this
> > problem would be immensely appreciated. Thank you in advance.
> >
> > Regards,
> > Andrew Rechenberg
> > Network Team, Sherman Financial Group
> > [email protected]
> >
> > --
> > To unsubscribe, send a message with 'unsubscribe linux-mm' in
> > the body to [email protected]. For more info on Linux MM,
> > see: http://www.linux-mm.org/
> >
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to [email protected]. For more info on Linux MM,
> see: http://www.linux-mm.org/
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/
Ken,
The 2.4.15pre7 kernel seems to have fixed my issue with kupdated and 4GB
RAM. We did some testing over the weekend and the box was still interactive
with a load of 7+. There still seems to be a lot of swapping going on
though. I've read from previous threads that 2.4 uses swap more readily
than 2.2 did, but should it use 10% of my swap and have almost 8MB
SwapCached?
Here are some numbers for example:
[root@mybox ~]# cat /proc/meminfo
total: used: free: shared: buffers: cached:
Mem: 4092899328 4082126848 10772480 0 12406784 3672317952
Swap: 542826496 57561088 485265408
MemTotal: 3996972 kB
MemFree: 10520 kB
MemShared: 0 kB
Buffers: 12116 kB
Cached: 3578108 kB
SwapCached: 8140 kB
Active: 2964668 kB
Inactive: 877168 kB
HighTotal: 3145720 kB
HighFree: 2084 kB
LowTotal: 851252 kB
LowFree: 8436 kB
SwapTotal: 530104 kB
SwapFree: 473892 kB
[root@mybox ~]# free
total used free shared buffers cached
Mem: 3996972 3986640 10332 0 12156 3577900
-/+ buffers/cache: 396584 3600388
Swap: 530104 56340 473764
The above question is more for my personal knowledge, but I would like to
know.
Thanks again for your help.
Regards,
Andy.
-----Original Message-----
From: Ken Brownfield [mailto:[email protected]]
Sent: Wednesday, November 21, 2001 12:07 PM
To: Rechenberg, Andrew
Subject: Re: kupdated high load with heavy disk I/O
Yeah, the kswapd/kupdated issue was patched in -pre7:
- me: modified Andrea VM page allocator tuning
-pre8 came out after I mailed you. ;-) So unless it's mentioned it
should stay in the kernel.
Of course, it's important to give it a try soon if you can, just to make
sure that it _does_ solve your specific problem. Especially before the
kernel is handed off to Marcelo.
Thx,
--
Ken.
On Wed, Nov 21, 2001 at 11:09:17AM -0500, Rechenberg, Andrew wrote:
| Ken,
|
| Thanks for the reply. I would assume then that any future 15-pre kernel
| would have the same fix? I ask because pre8 is now the current 15-pre.
|
| Thanks,
| Andy.
|
| -----Original Message-----
| From: Ken Brownfield [mailto:[email protected]]
| Sent: Tuesday, November 20, 2001 6:09 PM
| To: Rechenberg, Andrew
| Subject: Re: kupdated high load with heavy disk I/O
|
|
| Be sure to tru 2.4.15-pre7 which should fix your problem.
| --
| Ken.
| [email protected]
|
| On Tue, Nov 20, 2001 at 05:58:44PM -0500, Rechenberg, Andrew wrote:
| | I have to find time to down the box because it's production, but as soon
| as
| | I do I'll post the numbers here.
| |
| | Thanks for your help.
| |
| | Regards,
| | Andy.
| |
| |
| | > Could you please guys try to reproduce the problem with kernel
profiling
| | > turned on and send us the output of readprofile?
| |
| | > This way we can know which function is using more CPU time, thus we
can
| | > identify the problem.
| |
| |
| | On Wed, 14 Nov 2001, John McCutchan wrote:
| |
| | > Hi,
| | >
| | > I also have the exact same behaviour when running mkisofs. During the
| | > creation of the ISO the interactive feel is sluggish and after mkisofs
| | > is complete the box is sluggish and appears to lock up. During
| | > this sluggish period there is alot of disk activity. This is under
| | > 2.4.14
| | >
| | > John
| | > On Wed, Nov 14, 2001 at 06:01:23PM -0500, Rechenberg, Andrew wrote:
| | > > Hello,
| | > >
| | > > I have read some previous threads about kupdated consuming 99% of
CPU
| | under
| | > > intense disk I/O in kernel 2.4.x on the archives of linux-kernel
| (April
| | > > 2001), and some issues about I/O problems on linux-mm, but have yet
to
| | find
| | > > any suggestions or fixes. I am currently experiencing the same
issue
| | and
| | > > was wondering if anyone has any thoughts or suggestions on the
issue.
| I
| | am
| | > > not subscribed to the list so would you please CC: me directly on
any
| | > > responses? I can also check out the archives at theaimsgroup.com if
a
| | CC:
| | > > would not be appropriate. Thank you.
| | > >
| | > > The issue that I am having is that when there is a heavy amount a
disk
| | I/O,
| | > > the box becomes slightly unresponsive and kupdated is using 99.9% in
| | 'top.'
| | > > Sometimes the box appears to totally lock up. If one waits several
| | seconds
| | > > to a couple of minutes the system appears to 'unlock' and runs
| | sluggishly
| | > > for a while. This cycle will repeat itself until the I/O subsides.
| The
| | > > memory usage goes up to the full capacity of the box and then about
| 10MB
| | of
| | > > swap is used while this problem is occurring. Memory and swap does
| not
| | get
| | > > relinquished afer the incident.
| | > >
| | > > The issue appears in kernel 2.4.14 compiled directly from source
from
| | > > kernel.org with no patches. These problems manifest themselves with
| | only
| | > > one user doing heavy disk I/O. The normal user load on the box can
| run
| | > > between 350-450 users so this behavior would be unacceptable because
| the
| | > > application that is being run is interactive. With 450 users, and
the
| | same
| | > > process running on a 2.2.20 kernel the performance of the box is
| great,
| | with
| | > > only a very slightly noticeable slow down.
| | > >
| | > > I am running the Informix database UniVerse version 9.6.2.4 on a 4
| | processor
| | > > 700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled
by
| a
| | PERC
| | > > 2/DC RAID card with 128MB on-board cache (megaraid driver compiled
| | directly
| | > > in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in a
| | RAID5
| | > > configuration. The box has 4GB RAM, but is only using 2GB due to
the
| | move
| | > > back to the 2.2 kernel. The only kernel paramters that have been
| | modified
| | > > are in /proc/sys/kernel/sem. All filesystems are ext2.
| | > >
| | > > If you need any more detailed info, please let me know. Any help on
| | this
| | > > problem would be immensely appreciated. Thank you in advance.
| | > >
| | > > Regards,
| | > > Andrew Rechenberg
| | > > Network Team, Sherman Financial Group
| | > > [email protected]
| | > >
| | > > --
| | > > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | > > the body to [email protected]. For more info on Linux MM,
| | > > see: http://www.linux-mm.org/
| | > >
| | > --
| | > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | > the body to [email protected]. For more info on Linux MM,
| | > see: http://www.linux-mm.org/
| | >
| |
| | --
| | To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | the body to [email protected]. For more info on Linux MM,
| | see: http://www.linux-mm.org/
| | -
| | 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/
On Mon, Nov 26, 2001 at 10:08:27AM -0500, Rechenberg, Andrew wrote:
> Ken,
>
> The 2.4.15pre7 kernel seems to have fixed my issue with kupdated and 4GB
> RAM. We did some testing over the weekend and the box was still interactive
> with a load of 7+. There still seems to be a lot of swapping going on
> though. I've read from previous threads that 2.4 uses swap more readily
> than 2.2 did, but should it use 10% of my swap and have almost 8MB
> SwapCached?
if it only swapouts at a very slow rate over the time and it never
swapin, then yes it seems sane. You may also give a spin to 2.4.15aa1
that should swap a bit less.
Andrea
Yes, the extra swapping is more visible via kswapd in top, but as it was
explained to me (and time has confirmed in my experience) it's not the
performance hit that it may seem to be, and typically the opposite.
Linus posted an explanation for my similar question as part of the "[VM]
2.4.14/15-pre4 too "swap-happy"?" LKML thread.
Great to hear it solved your problem as well.
--
Ken.
[email protected]
On Mon, Nov 26, 2001 at 10:08:27AM -0500, Rechenberg, Andrew wrote:
| Ken,
|
| The 2.4.15pre7 kernel seems to have fixed my issue with kupdated and 4GB
| RAM. We did some testing over the weekend and the box was still interactive
| with a load of 7+. There still seems to be a lot of swapping going on
| though. I've read from previous threads that 2.4 uses swap more readily
| than 2.2 did, but should it use 10% of my swap and have almost 8MB
| SwapCached?
|
| Here are some numbers for example:
|
| [root@mybox ~]# cat /proc/meminfo
| total: used: free: shared: buffers: cached:
| Mem: 4092899328 4082126848 10772480 0 12406784 3672317952
| Swap: 542826496 57561088 485265408
| MemTotal: 3996972 kB
| MemFree: 10520 kB
| MemShared: 0 kB
| Buffers: 12116 kB
| Cached: 3578108 kB
| SwapCached: 8140 kB
| Active: 2964668 kB
| Inactive: 877168 kB
| HighTotal: 3145720 kB
| HighFree: 2084 kB
| LowTotal: 851252 kB
| LowFree: 8436 kB
| SwapTotal: 530104 kB
| SwapFree: 473892 kB
| [root@mybox ~]# free
| total used free shared buffers cached
| Mem: 3996972 3986640 10332 0 12156 3577900
| -/+ buffers/cache: 396584 3600388
| Swap: 530104 56340 473764
|
|
| The above question is more for my personal knowledge, but I would like to
| know.
|
| Thanks again for your help.
|
| Regards,
| Andy.
|
|
|
| -----Original Message-----
| From: Ken Brownfield [mailto:[email protected]]
| Sent: Wednesday, November 21, 2001 12:07 PM
| To: Rechenberg, Andrew
| Subject: Re: kupdated high load with heavy disk I/O
|
|
| Yeah, the kswapd/kupdated issue was patched in -pre7:
|
| - me: modified Andrea VM page allocator tuning
|
| -pre8 came out after I mailed you. ;-) So unless it's mentioned it
| should stay in the kernel.
|
| Of course, it's important to give it a try soon if you can, just to make
| sure that it _does_ solve your specific problem. Especially before the
| kernel is handed off to Marcelo.
|
| Thx,
| --
| Ken.
|
|
| On Wed, Nov 21, 2001 at 11:09:17AM -0500, Rechenberg, Andrew wrote:
| | Ken,
| |
| | Thanks for the reply. I would assume then that any future 15-pre kernel
| | would have the same fix? I ask because pre8 is now the current 15-pre.
| |
| | Thanks,
| | Andy.
| |
| | -----Original Message-----
| | From: Ken Brownfield [mailto:[email protected]]
| | Sent: Tuesday, November 20, 2001 6:09 PM
| | To: Rechenberg, Andrew
| | Subject: Re: kupdated high load with heavy disk I/O
| |
| |
| | Be sure to tru 2.4.15-pre7 which should fix your problem.
| | --
| | Ken.
| | [email protected]
| |
| | On Tue, Nov 20, 2001 at 05:58:44PM -0500, Rechenberg, Andrew wrote:
| | | I have to find time to down the box because it's production, but as soon
| | as
| | | I do I'll post the numbers here.
| | |
| | | Thanks for your help.
| | |
| | | Regards,
| | | Andy.
| | |
| | |
| | | > Could you please guys try to reproduce the problem with kernel
| profiling
| | | > turned on and send us the output of readprofile?
| | |
| | | > This way we can know which function is using more CPU time, thus we
| can
| | | > identify the problem.
| | |
| | |
| | | On Wed, 14 Nov 2001, John McCutchan wrote:
| | |
| | | > Hi,
| | | >
| | | > I also have the exact same behaviour when running mkisofs. During the
| | | > creation of the ISO the interactive feel is sluggish and after mkisofs
| | | > is complete the box is sluggish and appears to lock up. During
| | | > this sluggish period there is alot of disk activity. This is under
| | | > 2.4.14
| | | >
| | | > John
| | | > On Wed, Nov 14, 2001 at 06:01:23PM -0500, Rechenberg, Andrew wrote:
| | | > > Hello,
| | | > >
| | | > > I have read some previous threads about kupdated consuming 99% of
| CPU
| | | under
| | | > > intense disk I/O in kernel 2.4.x on the archives of linux-kernel
| | (April
| | | > > 2001), and some issues about I/O problems on linux-mm, but have yet
| to
| | | find
| | | > > any suggestions or fixes. I am currently experiencing the same
| issue
| | | and
| | | > > was wondering if anyone has any thoughts or suggestions on the
| issue.
| | I
| | | am
| | | > > not subscribed to the list so would you please CC: me directly on
| any
| | | > > responses? I can also check out the archives at theaimsgroup.com if
| a
| | | CC:
| | | > > would not be appropriate. Thank you.
| | | > >
| | | > > The issue that I am having is that when there is a heavy amount a
| disk
| | | I/O,
| | | > > the box becomes slightly unresponsive and kupdated is using 99.9% in
| | | 'top.'
| | | > > Sometimes the box appears to totally lock up. If one waits several
| | | seconds
| | | > > to a couple of minutes the system appears to 'unlock' and runs
| | | sluggishly
| | | > > for a while. This cycle will repeat itself until the I/O subsides.
| | The
| | | > > memory usage goes up to the full capacity of the box and then about
| | 10MB
| | | of
| | | > > swap is used while this problem is occurring. Memory and swap does
| | not
| | | get
| | | > > relinquished afer the incident.
| | | > >
| | | > > The issue appears in kernel 2.4.14 compiled directly from source
| from
| | | > > kernel.org with no patches. These problems manifest themselves with
| | | only
| | | > > one user doing heavy disk I/O. The normal user load on the box can
| | run
| | | > > between 350-450 users so this behavior would be unacceptable because
| | the
| | | > > application that is being run is interactive. With 450 users, and
| the
| | | same
| | | > > process running on a 2.2.20 kernel the performance of the box is
| | great,
| | | with
| | | > > only a very slightly noticeable slow down.
| | | > >
| | | > > I am running the Informix database UniVerse version 9.6.2.4 on a 4
| | | processor
| | | > > 700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled
| by
| | a
| | | PERC
| | | > > 2/DC RAID card with 128MB on-board cache (megaraid driver compiled
| | | directly
| | | > > in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in a
| | | RAID5
| | | > > configuration. The box has 4GB RAM, but is only using 2GB due to
| the
| | | move
| | | > > back to the 2.2 kernel. The only kernel paramters that have been
| | | modified
| | | > > are in /proc/sys/kernel/sem. All filesystems are ext2.
| | | > >
| | | > > If you need any more detailed info, please let me know. Any help on
| | | this
| | | > > problem would be immensely appreciated. Thank you in advance.
| | | > >
| | | > > Regards,
| | | > > Andrew Rechenberg
| | | > > Network Team, Sherman Financial Group
| | | > > [email protected]
| | | > >
| | | > > --
| | | > > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | | > > the body to [email protected]. For more info on Linux MM,
| | | > > see: http://www.linux-mm.org/
| | | > >
| | | > --
| | | > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | | > the body to [email protected]. For more info on Linux MM,
| | | > see: http://www.linux-mm.org/
| | | >
| | |
| | | --
| | | To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | | the body to [email protected]. For more info on Linux MM,
| | | see: http://www.linux-mm.org/
| | | -
| | | 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/
Just as an FYI, I am now running 2.4.16 on my production box and it has been
running smooth since Monday afternoon. The VM issues that I was having in
2.4.14 seemed to have been resolved. Thanks again to everyone for their
help.
Regards,
Andy.
-----Original Message-----
From: Ken Brownfield [mailto:[email protected]]
Sent: Monday, November 26, 2001 6:08 PM
To: Rechenberg, Andrew
Cc: '[email protected]'; '[email protected]'
Subject: Re: kupdated high load with heavy disk I/O
Yes, the extra swapping is more visible via kswapd in top, but as it was
explained to me (and time has confirmed in my experience) it's not the
performance hit that it may seem to be, and typically the opposite.
Linus posted an explanation for my similar question as part of the "[VM]
2.4.14/15-pre4 too "swap-happy"?" LKML thread.
Great to hear it solved your problem as well.
--
Ken.
[email protected]
On Mon, Nov 26, 2001 at 10:08:27AM -0500, Rechenberg, Andrew wrote:
| Ken,
|
| The 2.4.15pre7 kernel seems to have fixed my issue with kupdated and 4GB
| RAM. We did some testing over the weekend and the box was still
interactive
| with a load of 7+. There still seems to be a lot of swapping going on
| though. I've read from previous threads that 2.4 uses swap more readily
| than 2.2 did, but should it use 10% of my swap and have almost 8MB
| SwapCached?
|
| Here are some numbers for example:
|
| [root@mybox ~]# cat /proc/meminfo
| total: used: free: shared: buffers: cached:
| Mem: 4092899328 4082126848 10772480 0 12406784 3672317952
| Swap: 542826496 57561088 485265408
| MemTotal: 3996972 kB
| MemFree: 10520 kB
| MemShared: 0 kB
| Buffers: 12116 kB
| Cached: 3578108 kB
| SwapCached: 8140 kB
| Active: 2964668 kB
| Inactive: 877168 kB
| HighTotal: 3145720 kB
| HighFree: 2084 kB
| LowTotal: 851252 kB
| LowFree: 8436 kB
| SwapTotal: 530104 kB
| SwapFree: 473892 kB
| [root@mybox ~]# free
| total used free shared buffers cached
| Mem: 3996972 3986640 10332 0 12156 3577900
| -/+ buffers/cache: 396584 3600388
| Swap: 530104 56340 473764
|
|
| The above question is more for my personal knowledge, but I would like to
| know.
|
| Thanks again for your help.
|
| Regards,
| Andy.
|
|
|
| -----Original Message-----
| From: Ken Brownfield [mailto:[email protected]]
| Sent: Wednesday, November 21, 2001 12:07 PM
| To: Rechenberg, Andrew
| Subject: Re: kupdated high load with heavy disk I/O
|
|
| Yeah, the kswapd/kupdated issue was patched in -pre7:
|
| - me: modified Andrea VM page allocator tuning
|
| -pre8 came out after I mailed you. ;-) So unless it's mentioned it
| should stay in the kernel.
|
| Of course, it's important to give it a try soon if you can, just to make
| sure that it _does_ solve your specific problem. Especially before the
| kernel is handed off to Marcelo.
|
| Thx,
| --
| Ken.
|
|
| On Wed, Nov 21, 2001 at 11:09:17AM -0500, Rechenberg, Andrew wrote:
| | Ken,
| |
| | Thanks for the reply. I would assume then that any future 15-pre kernel
| | would have the same fix? I ask because pre8 is now the current 15-pre.
| |
| | Thanks,
| | Andy.
| |
| | -----Original Message-----
| | From: Ken Brownfield [mailto:[email protected]]
| | Sent: Tuesday, November 20, 2001 6:09 PM
| | To: Rechenberg, Andrew
| | Subject: Re: kupdated high load with heavy disk I/O
| |
| |
| | Be sure to tru 2.4.15-pre7 which should fix your problem.
| | --
| | Ken.
| | [email protected]
| |
| | On Tue, Nov 20, 2001 at 05:58:44PM -0500, Rechenberg, Andrew wrote:
| | | I have to find time to down the box because it's production, but as
soon
| | as
| | | I do I'll post the numbers here.
| | |
| | | Thanks for your help.
| | |
| | | Regards,
| | | Andy.
| | |
| | |
| | | > Could you please guys try to reproduce the problem with kernel
| profiling
| | | > turned on and send us the output of readprofile?
| | |
| | | > This way we can know which function is using more CPU time, thus we
| can
| | | > identify the problem.
| | |
| | |
| | | On Wed, 14 Nov 2001, John McCutchan wrote:
| | |
| | | > Hi,
| | | >
| | | > I also have the exact same behaviour when running mkisofs. During
the
| | | > creation of the ISO the interactive feel is sluggish and after
mkisofs
| | | > is complete the box is sluggish and appears to lock up. During
| | | > this sluggish period there is alot of disk activity. This is under
| | | > 2.4.14
| | | >
| | | > John
| | | > On Wed, Nov 14, 2001 at 06:01:23PM -0500, Rechenberg, Andrew wrote:
| | | > > Hello,
| | | > >
| | | > > I have read some previous threads about kupdated consuming 99% of
| CPU
| | | under
| | | > > intense disk I/O in kernel 2.4.x on the archives of linux-kernel
| | (April
| | | > > 2001), and some issues about I/O problems on linux-mm, but have
yet
| to
| | | find
| | | > > any suggestions or fixes. I am currently experiencing the same
| issue
| | | and
| | | > > was wondering if anyone has any thoughts or suggestions on the
| issue.
| | I
| | | am
| | | > > not subscribed to the list so would you please CC: me directly on
| any
| | | > > responses? I can also check out the archives at theaimsgroup.com
if
| a
| | | CC:
| | | > > would not be appropriate. Thank you.
| | | > >
| | | > > The issue that I am having is that when there is a heavy amount a
| disk
| | | I/O,
| | | > > the box becomes slightly unresponsive and kupdated is using 99.9%
in
| | | 'top.'
| | | > > Sometimes the box appears to totally lock up. If one waits
several
| | | seconds
| | | > > to a couple of minutes the system appears to 'unlock' and runs
| | | sluggishly
| | | > > for a while. This cycle will repeat itself until the I/O
subsides.
| | The
| | | > > memory usage goes up to the full capacity of the box and then
about
| | 10MB
| | | of
| | | > > swap is used while this problem is occurring. Memory and swap
does
| | not
| | | get
| | | > > relinquished afer the incident.
| | | > >
| | | > > The issue appears in kernel 2.4.14 compiled directly from source
| from
| | | > > kernel.org with no patches. These problems manifest themselves
with
| | | only
| | | > > one user doing heavy disk I/O. The normal user load on the box
can
| | run
| | | > > between 350-450 users so this behavior would be unacceptable
because
| | the
| | | > > application that is being run is interactive. With 450 users, and
| the
| | | same
| | | > > process running on a 2.2.20 kernel the performance of the box is
| | great,
| | | with
| | | > > only a very slightly noticeable slow down.
| | | > >
| | | > > I am running the Informix database UniVerse version 9.6.2.4 on a 4
| | | processor
| | | > > 700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled
| by
| | a
| | | PERC
| | | > > 2/DC RAID card with 128MB on-board cache (megaraid driver compiled
| | | directly
| | | > > in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in
a
| | | RAID5
| | | > > configuration. The box has 4GB RAM, but is only using 2GB due to
| the
| | | move
| | | > > back to the 2.2 kernel. The only kernel paramters that have been
| | | modified
| | | > > are in /proc/sys/kernel/sem. All filesystems are ext2.
| | | > >
| | | > > If you need any more detailed info, please let me know. Any help
on
| | | this
| | | > > problem would be immensely appreciated. Thank you in advance.
| | | > >
| | | > > Regards,
| | | > > Andrew Rechenberg
| | | > > Network Team, Sherman Financial Group
| | | > > [email protected]
| | | > >
| | | > > --
| | | > > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | | > > the body to [email protected]. For more info on Linux MM,
| | | > > see: http://www.linux-mm.org/
| | | > >
| | | > --
| | | > To unsubscribe, send a message with 'unsubscribe linux-mm' in
| | | > the body to [email protected]. For more info on Linux MM,
| | | > see: http://www.linux-mm.org/
| | | >
| | |
| | | --
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| | | see: http://www.linux-mm.org/
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