tree f91163833653b2ad4ddc2bdd62d15a7dc5ef3688
parent 5809109f5300c00f057d0a6d2d1e7d5bf075b4a5
author Vinayak Menon <vinmenon@codeaurora.org> 1439981199 +0530
committer Vinayak Menon <vinmenon@codeaurora.org> 1500442153 +0530

mm: vmpressure: account allocstalls only on higher pressures

At present any vmpressure value is scaled up if the pages are
reclaimed through direct reclaim. This can result in false
vmpressure values. Consider a case where a device is booted up
and most of the memory is occuppied by file pages. kswapd will
make sure that high watermark is maintained. Now when a sudden
huge allocation request comes in, the system will definitely
have to get into direct reclaims. The vmpressures can be very low,
but because of allocstall accounting logic even these low values
will be scaled to values nearing 100. This can result in
unnecessary LMK kills for example. So define a tunable threshold
for vmpressure above which the allocstalls will be accounted.

Change-Id: Idd7c6724264ac89f1f68f2e9d70a32390ffca3e5
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>