On 8/15/19 1:25 PM, Tejun Heo wrote: > WB_FRN_TIME_CUT_DIV is used to tell the foreign inode detection logic > to ignore short writeback rounds to prevent getting confused by a > burst of short writebacks. The parameter is currently 2 meaning that > anything smaller than half of the running average writback duration > will be ignored. > > This is unnecessarily aggressive. The detection logic uses 16 history > slots and is already reasonably protected against some short bursts > confusing it and the current parameter can lead to tens of seconds of > missed detection depending on the writeback pattern. > > Let's change the parameter to 8, so that it only ignores writeback > with are smaller than 12.5% of the current running average. > > v2: Add comment explaining what's going on with the foreign detection > parameters. Applied 1-2 for 5.4, thanks. -- Jens Axboe
