On Wed, 13 Nov 2019 14:49:21 +0800 Coly Li wrote: > On 2019/11/13 2:10 下午, Christian Balzer wrote: > > On Wed, 13 Nov 2019 11:44:50 +0800 Coly Li wrote: > > > > [snip] > >> > >> Hi Christian, > >> > >> Could you please try the attached patch in your environment ? Let's see > >> whether it makes things better on your side. > >> > > > > Don't have custom/handrolled kernels on those machines, but I'll give it a > > spin later. > > Looking at the code I'm sure it will work, as in not going to full speed > > when idle. > > > > Is there any reason for this being a flag instead of actually setting the > > max writeback rate, as mentioned when comparing this to MD RAID min/max? > > > > What this does now is having writeback_rate_minimum both as the min and max > > rate for non-dirty pressure flushing. > > Whereas most people who want to actually set these values would probably > > be interested in a min rate as it is now (to drain things effectively w/o > > going overboard) and a max rate that never should be exceeded even if the > > PDC thinks otherwise. > > For the max writeback rate limit, so far it is handled by the PDC > controller. I will have a try whether I can make it myself before > anybody helps to post patch. But it is at quite low priority location in > my todo list, I need to complete other tasks firstly which are not easy > neither and spent a lot of time already. > > I post the patch to upstream for Linux v5.5, and add Reported-by: tag > with your email address. > Yes, I saw, thanks. No worries and hurry. I can probably apply that patch fairly easily against 4.19. Regards, Christian > Thanks. > -- > > Coly Li > -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Rakuten Mobile Inc.
