Re: [PATCH 0/5] Reduce GFP_ATOMIC allocation failures, candidate fix V3

Frans Pop
2009-11-13T09:04:27Z

On Thursday 12 November 2009, Mel Gorman wrote:
> Changelog since V2
> o Dropped the kswapd-quickly-notice-high-order patch. In more detailed
> testing, it made latencies even worse as kswapd slept more on
> high-order congestion causing order-0 direct reclaims.
> o Added changes to how congestion_wait() works
> o Added a number of new patches altering the behaviour of reclaim

I have tested this series on top of .32-rc7. First impression is that it
does seem to improve my test case, but does not yet completely solve it.

My last gitk instance now loads more smoothly for most of the time it takes
to complete, but I still see a choke point where things freeze for a while
and where I get SKB allocation errors from my wireless.
However, that choke point does seem to happen later and to be shorter than
without the patches.

I'll try to do additional tests (with .31). If you'd like me to run this
set with your instrumentation patch for congestion_wait, then please let
me know.

Chris Mason's analysis regarding dm-crypt workqueues in reply to your other
mail looks very interesting.

Cheers,
FJP