Linux kernel folk,
I have been having extremely serious problems with kswapd. I noted
that changes had occured after Rik's patch to 2.3.99pre3, I grabbed
that and my kswapd problem is gone. As a case in point, while running
2.3.99pre6 I was getting 2 gig/hr backing up to my tape drive, and my
system was fully unusable in the process. With 2.3.99pre3 my system
was really usable during the process and transfered 5gig/hr. I
removed all my swap partitions and the problem still persisted under
2.3.pre6 . So I'm pretty sure that Rik's patch was the cause of the
problem... but why? He just got rid of the silly while, right?
Didn't someone mention that basically that just kept the process
spinning around for the rest of it's time slice? Maybe it really did
something during that time that prevented a context switch problem?
(That doesn't make any sense to me..., but it feels right if that
makes any sense at all... which it doesn't I know. i.e. obviously
didn't do anything..., but maybe somebody knows what I mean because
I'm having trouble putting it to words)
Anyway, just wanted to throw out a "me too", and bring up the history
of it. Rik if you want to send me a patch to test, I'd be happy to
help you out in testing, and might mess arround with the code later
this week. (Oh, BTW Rik, I don't mean to "blame" you, just wanted to
bring up the history of it) Has anyone tried copying Riks changes into
a 2.3.99pre3 based kernel to isolate that one change and tried? Rik
if you forward me your original patch against 2.3.99pre3 I'll do that
(or send me a URL). Maybe the problem creaped in from another change.
I noted however, that pre6 seemed a lot faster until kswapd started
going crazy..., was there another change to the caching code that may
have "interacted" with Rik's patch? (Caching seems to be much much
more aggressive)
One other note. This is ALL related to disk i/o. But not
swapping to disk. It seems that the caching of disk files is causing
the problem... over aggressive maybe? Because basically anything I do
that's disk intensive, it fills the cache, and then it's spending
loads of CPU time swapping stuff in and out of *memory* not virtual
memory. (Like I noted, the problem persists even if you turn off all
swap partitions)
Thanks,
Shane Nay.
(non kernel hacker that I am..., just another programmer who was hoping
he might be of some use.)
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This archive was generated by hypermail 2b29 : Sun Apr 30 2000 - 21:00:17 EST