Re: Subject: [PATCH] [lmk] improve ANR produce rate caused by high io wait on android,create a thread for lowmem killer instead of usingkswapd

["greg@kroah.com" <greg@kroah.com>]

On Fri, Dec 14, 2012 at 05:51:47PM +0000, Tu, Xiaobing wrote:
> Resend to fix the typo issue.
> 
> 
> Subject: [PATCH] [lmk] create a thread for low mem killer instead of using kswapd
> 
> Currently low mem killer is registered as a shrinker and will be
> invoked by kswapd. Since low mem killer and kswapd has different
> criteria to invoke to work -- kswap wakes up when watermark of some
> certain order in zone is low, and low mem killer should do its job
> when free memory is below the min free threshold. In the case that
> the kswapd isn't waked up and lmk is, the killed process selected
> by lmk will release memory so that the kswapd doesn't need towork
> any more.So it is not appropriate to mix them together. A 20 minutes
> average vmstat shows that the iowait/page fault has huge improvement.
> In this way, it can reduce the chance of ANR due to high iowait.
> 
> orignal:
> flt    wa
> 62.70 2.00
> 
> with patch
> flt    wa
> 2.32  0.01
> 
> Signed-off-by: Zhang Di <di.zhang@intel.com>
> Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
> ---
>  drivers/staging/android/lowmemorykiller.c |   87 +++++++++++++++++++++++++++--
>  mm/page_alloc.c                           |    7 ++-
>  mm/vmscan.c                               |    2 +
>  3 files changed, 89 insertions(+), 7 deletions(-)

This patch breaks the build if the android code is not selected, please
fix this up and resend if you really need this.

thanks,

greg k-h