On 05/13/2011 07:42 AM, KOSAKI Motohiro wrote:
While testing for memcg aware swap token, I observed a swap token was often grabbed an intermittent running process (eg init, auditd) and they never release a token. Why? Currently, swap toke priority is only decreased at page fault path. Then, if the process sleep immediately after to grab swap token, their swap token priority never be decreased. That makes obviously undesired result. This patch implement very poor (and lightweight) priority decay mechanism. It only be affect to the above corner case and doesn't change swap tendency workload performance (eg multi process qsbench load)
Ohhh, good catch. The original swap token algorithm did not have this problem, and I never caught the fact that the replacement (which is better in many ways) does...
Signed-off-by: KOSAKI Motohiro<kosaki.motohiro@xxxxxxxxxxxxxx>
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