Re: vfork: out of memory, when there's plenty of swap free

Andrea Arcangeli (andrea@e-mind.com)
Sun, 14 Mar 1999 04:29:04 +0100 (CET)


On Sat, 13 Mar 1999, Alan Cox wrote:

>> run make -j and watch. Peak swap usage gets to 50Meg or so, then it
>> starts dying with vfork: out of memory. [Can someone reproduce these,
>> please?]
>
>Yes I can reproduce the running out of 8K block problem easily. Its the
>lack of a memory defragmentation goal in the current 2.2 vm

It's not the lack of defragmentation but due bad allocation of memory.
Just to make an example look at the inode cache. It uses a _bad_ way to
alloc memory. That's the _best_ way to generate _persistent_ fragmentation
all over the place.

And btw I think that for vmlloced areas would be possible to defrag them
at runtime, but for normal __get_free_pages memory it's not possible, it's
the allocation in first place that has to be smart to avoid fragmentation
according to me.

Andrea Arcangeli

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