On 27 Nov 2018, at 14:54, Josef Bacik wrote: > On Tue, Nov 27, 2018 at 10:26:15AM +0200, Nikolay Borisov wrote: >> >> >> On 21.11.18 г. 21:09 ч., Josef Bacik wrote: >>> The cleaner thread usually takes care of delayed iputs, with the >>> exception of the btrfs_end_transaction_throttle path. The cleaner >>> thread only gets woken up every 30 seconds, so instead wake it up to >>> do >>> it's work so that we can free up that space as quickly as possible. >> >> Have you done any measurements how this affects the overall system. I >> suspect this introduces a lot of noise since now we are going to be >> doing a thread wakeup on every iput, does this give a chance to have >> nice, large batches of iputs that the cost of wake up can be >> amortized >> across? > > I ran the whole patchset with our A/B testing stuff and the patchset > was a 5% > win overall, so I'm inclined to think it's fine. Thanks,
It's a good point though, a delayed wakeup may be less overhead. -chris
