On 05/15, Chao Yu wrote: > Hi Ju Hyung, > > On 2019/5/14 19:30, Ju Hyung Park wrote: > > Hi Chao, > > > > On Tue, May 14, 2019 at 8:19 PM Chao Yu <[email protected]> wrote: > >>> I've been using this(with a slightly different code) for years and yet to > >>> notice > >>> any spikes in lags/slowdowns. Worst scenario, I'd just have to deal with > >>> an > >>> added split second(100ms max?) delay in screen wake-up. > >> > >> I'm not sure about why this happened... maybe you need to do some test to > >> analyse the root cause of it, filesystem/device fragment? too many > >> undiscard > >> space? or non-storage issue? > > > > Um, I'm not sure you understood what I said. > > What I meant is that I haven't found any issues with using an approach > > like this(gc_urgent with 1ms sleep intervals) for years on various > > Android devices. > > Ah, sorry, I misread what you said. > > > > >> I agreed that it should done as soon as possible, but it needs to consider > >> IO > >> race in between Apps after screen wake-up and BGGC to avoid potential ANR. > > > > I actually need to check whether vold turns off gc_urgent immediately > > after screen turns itself back on. > > I don't think we need to take potential ANR in to account *if* vold > > stops gc_urgent right after screen-on. What do you think? > > What do you mean, I didn't catch it... > > > > >> It's userspace strategy, we can change both of them > >> (vold_wait_time/gc_urgent_sleep_time) in userspace if current value > >> doesn't make > >> any sense. > > > > Even the user can set the tunables themselves, the default should be > > sensical imo. > > Agreed, how about adjusting this default value according device type, for fast > device, like SSD, we can set default interval to very small value. > > Maybe we can implement this base on below commit if you agreed. > > f2fs: support tunning for multiple kind of storage device > > Thanks, > > > An "urgent" GC that only GCs up-to 2 segments per second doesn't sound > > that "urgent" :p
Yes, it seems I set it too conservatively at that time. It'd be fine to decrease the default time, but I'd prefer to remain the sysfs entry in order for user to configure it just in case. It'd be also great to have the above Chao's patch to have some default values regarding to discard/GC policies. Thanks, > > > > Thanks. > > . > > > > > _______________________________________________ > Linux-f2fs-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
