Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [Intel-IOMMU 02/10] Library routine for pre-allocat pool handling | Date | Sat, 9 Jun 2007 11:47:23 +0200 |
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> > Now there is a anon dirty limit since a few releases, but I'm not > > fully convinced it solves the problem completely. > > A gut feeling or is there more?
Lots of other subsystem can allocate a lot of memory and they usually don't cooperate and have similar dirty limit concepts. So you could run out of usable memory anyways and then have a similar issue.
For example a flood of network packets could always steal your GFP_ATOMIC pools very quickly in the background (gigabit or 10gig can transfer a lot of data very quickly)
Also iirc try_to_free_pages() is not completely fair and might fail under extreme load for some requesters.
Not requiring memory allocation for any IO would be certainly safer.
Anyways, it's a theoretic question because you can't sleep in there anyways unless something drastic changes in the driver interfaces.
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