Hi, On 07/07/2010 02:00 PM, Uma shankar wrote:
> Occasionally, xvMalloc will try to grow the pool. > This memory allocation can fail under low memory. > > This will be informed to the kernel as a "device write" failure. > The page which was being written will not be reclaimed, but > the kernel will continue to try swap out of other pages ( as kernel > thinks that swap has free space. ) > > Wont this lead to the reclaim code ( kswapd or the direct reclaim > path ) hogging the processor for some time before OOM is > finally announced ? > > And what if a NOFAIL allocation attempt results in this ? > > Have you analysed this scenario ? > If you ever get too many write failures, its an indication that you have oversized ramzswap device. From what I have observed, swap write failure quickly lead to system hang. In ideal case, ramzswap should be able to dynamically resize based on cache hit-rate, system memory pressure etc., but all this is not yet done. So, for now, best would be to experiment a bit and get some idea of ramzswap disksize that helps your workload while still not getting into messy conditions like OOM, swap write failures. Thanks, Nitin _______________________________________________ linux-mm-cc mailing list [email protected] http://lists.laptop.org/listinfo/linux-mm-cc
