On 10/8/21 15:53, Mel Gorman wrote: > Neil Brown raised concerns about callers of reclaim_throttle specifying > a timeout value. The original timeout values to congestion_wait() were > probably pulled out of thin air or copy&pasted from somewhere else. > This patch centralises the timeout values and selects a timeout based > on the reason for reclaim throttling. These figures are also pulled > out of the same thin air but better values may be derived > > Running a workload that is throttling for inappropriate periods > and tracing mm_vmscan_throttled can be used to pick a more appropriate > value. Excessive throttling would pick a lower timeout where as > excessive CPU usage in reclaim context would select a larger timeout. > Ideally a large value would always be used and the wakeups would > occur before a timeout but that requires careful testing. > > Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
