| Date | Wed, 27 Sep 2000 15:56:08 +0200 | From | Andrea Arcangeli <> | Subject | Re: [patch] vmfixes-2.4.0-test9-B2 - fixing deadlocks |
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On Wed, Sep 27, 2000 at 10:11:43AM +0200, Christoph Rohland wrote: > I just checked one oracle system and it did not lock the memory. And I
If that memory is used for I/O cache then such memory should released when the system runs into swap instead of swapping it out too (otherwise it's not cache anymore and it could be slower than re-reading from disk the real data in rawio).
> Customers with performance problems very often start with too little > memory, but they cannot upgrade until this really big job finishes :-( > > Another issue about shm swapping is interactive transactions, where > some users have very large contexts and go for a coffee before > submitting. This memory can be swapped.
Agreed, that's why I said shm performance under swap is very important as well (I'm not understimating it).
But again: if the shm contains I/O cache it should be released and not swapped out. Swapping out shmfs that contains I/O cache would be exactly like swapping out page-cache.
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