Re: long stalls

[Russell Leighton]

I am pretty sure we are at 2.4.19.

Brian Tinsley wrote:

> Out of curiosity, which RH kernel are you using? I moved on to 2.4.19 
> and 2.4.20 primarily because the RH 2.4.18 series of kernels 
> apparently has a scheduler bug (at least one) that causes the 
> heartbeat software from Linux-HA to loose heartbeat signals and 
> failover. Not a good scenario when you are trying to provide HA 
> systems to hospitals!
>
>
> Russell Leighton wrote:
>
>>
>> I can't help, but I can echo a "me too".
>>
>> We only see it when I have 2 file I/O intensive processes...they both 
>> will just stop for some few seconds, system seems idle...then
>> they just start again. RH7.3 SMP, Dual PIII, 4GB RAM, 3com RAID 
>> Controller .
>>
>> Brian Tinsley wrote:
>>
>>> We have been having terrible problems with long stalls, meaning from 
>>> a couple of minutes to an hour, happening when filesystem I/O load 
>>> gets high. The system time as reported by vmstat or sar will 
>>> increase up to 99% and as it spreads to each procesor, the system 
>>> becomes completely unresponsive (except that it responds to pings 
>>> just fine - interesting!). When the system finally returns to the 
>>> world of the living, the only evidence that something bad has 
>>> happened is the runtime for kswapd is abnormally high. I have seen 
>>> this happen with the stock 2.4.17, 2.4.19, and 2.4.20 kernels on SMP 
>>> PIII and PIV machines (either 4GB or 8GB RAM, all SCSI disks, dual 
>>> GigE NICs). I've searched the lkml archives and google and have 
>>> found several similar postings, but there is never an explanation or 
>>> resolution. Any help would be *very* much appreciated! If any info 
>>> from the system in question is desired, I will be glad to provide it.
>>>
>>>
>>>
>>
>