Messages in this thread |  | | | Date | Wed, 8 Feb 2012 15:26:46 +0000 | | From | Mel Gorman <> | | Subject | Re: [PATCH 00/15] Swap-over-NBD without deadlocking V8 |
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On Wed, Feb 08, 2012 at 08:51:11PM +0800, Hillf Danton wrote: > On Tue, Feb 7, 2012 at 9:27 PM, Mel Gorman <mgorman@suse.de> wrote: > > On Tue, Feb 07, 2012 at 08:45:18PM +0800, Hillf Danton wrote: > >> If it is feasible to bypass hang by tuning min_mem_kbytes, > > > > No. Increasing or descreasing min_free_kbytes changes the timing but it > > will still hang. > > > >> things may > >> become simpler if NICs are also tagged. > > > > That would mean making changes to every driver and they do not necessarily > > know what higher level protocol like TCP they are transmitting. How is > > that simpler? What is the benefit? > > > The benefit is to avoid allocating sock buffer in softirq by recycling, > then the changes in VM core maybe less. >
The VM is responsible for swapping. It's reasonable that the core VM has responsibility for it without trying to shove complexity into drivers or elsewhere unnecessarily. I see some benefit in following on by recycling some skbs and only allocating from softirq if no recycled skbs are available. That potentially improves performance but I do not recycling as a replacement.
-- Mel Gorman SUSE Labs
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