APPLIED [PATCH 0/2] [Natty SRU] kswapd consumes CPU during heavy I/O

[Tim Gardner]

On 06/17/2011 04:06 AM, Colin King wrote:
> From: Colin Ian King<colin.king at canonical.com>
>
> SRU Request:
>
> System hangs have been observed when performing heavy I/O on
> sandybridge systems with small memory footprints (for example,
> less than 2GB of memory). kswapd consumes all the CPU and the
> machine effectively becomes unusable because kswapd is missing
> every cond_resched().  Also, we need to invert the logic in
> commit 1741c877 ("mm: kswapd: keep kswapd awake for high-order
> allocations until a percentage of the node is balanced") to
> allow kswapd to go to sleep when balanced for high orders.
>
> Testing involved multiply copying ~600MB of files from an install
> image on a laptop with 2GB of memory. A 2.5 hour (150 iteration)
> soak test cannot trip the hang with these patches, where as
> without them the bug occurs in the first 5 to 30 iterations.
>
> BugLink: http://bugs.launchpad.net/bugs/755066
>
> Patches cherry-picked from upstream and are in GregKH's stable 2.6.38.8
>
> Johannes Weiner (1):
>    mm: vmscan: correct use of pgdat_balanced in sleeping_prematurely
>
> Minchan Kim (1):
>    mm: vmscan: correctly check if reclaimer should schedule during
>      shrink_slab
>
>   mm/vmscan.c |   11 ++++++++---
>   1 files changed, 8 insertions(+), 3 deletions(-)
>
>


-- 
Tim Gardner tim.gardner at canonical.com