Re: [PATCH v1 0/3] per-process reclaim

[ZhaoJunmin Zhao(Junmin)]

å 2016/6/13 19:50, Chen Feng åé:
> Hi Minchan,
>
> On 2016/6/13 15:50, Minchan Kim wrote:
> > Hi all,
> >
> > http://thread.gmane.org/gmane.linux.kernel/1480728
> >
> > I sent per-process reclaim patchset three years ago. Then, last
> > feedback from akpm was that he want to know real usecase scenario.
> >
> > Since then, I got question from several embedded people of various
> > company "why it's not merged into mainline" and heard they have used
> > the feature as in-house patch and recenlty, I noticed android from
> > Qualcomm started to use it.
> >
> > Of course, our product have used it and released it in real procuct.
> >
> > Quote from Sangwoo Park <angwoo2.park@xxxxxxx>
> > Thanks for the data, Sangwoo!
> > "
> > - Test scenaro
> >    - platform: android
> >    - target: MSM8952, 2G DDR, 16G eMMC
> >    - scenario
> >      retry app launch and Back Home with 16 apps and 16 turns
> >      (total app launch count is 256)
> >    - result:
> > 			  resume count   |  cold launching count
> > -----------------------------------------------------------------
> >   vanilla           |           85        |          171
> >   perproc reclaim   |           184       |           72
> > "
> >
> > Higher resume count is better because cold launching needs loading
> > lots of resource data which takes above 15 ~ 20 seconds for some
> > games while successful resume just takes 1~5 second.
> >
> > As perproc reclaim way with new management policy, we could reduce
> > cold launching a lot(i.e., 171-72) so that it reduces app startup
> > a lot.
> >
> > Another useful function from this feature is to make swapout easily
> > which is useful for testing swapout stress and workloads.
> Thanks Minchan.
>
> Yes, this is useful interface when there are memory pressure and let the userspace(Android)
> to pick process for reclaim. We also take there series into our platform.
>
> But I have a question on the reduce app startup time. Can you also share your
> theory(management policy) on how can the app reduce it's startup time?
>
>
> > Thanks.

Yes, In Huawei device, we use the interface now! Now according to 
procsss LRU state in ActivityManagerService, we can reclaim some process
in proactive way.

> > Cc: Redmond <u93410091@xxxxxxxxx>
> > Cc: ZhaoJunmin Zhao(Junmin) <zhaojunmin@xxxxxxxxxx>
> > Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
> > Cc: Juneho Choi <juno.choi@xxxxxxx>
> > Cc: Sangwoo Park <sangwoo2.park@xxxxxxx>
> > Cc: Chan Gyun Jeong <chan.jeong@xxxxxxx>
> >
> > Minchan Kim (3):
> >    mm: vmscan: refactoring force_reclaim
> >    mm: vmscan: shrink_page_list with multiple zones
> >    mm: per-process reclaim
> >
> >   Documentation/filesystems/proc.txt |  15 ++++
> >   fs/proc/base.c                     |   1 +
> >   fs/proc/internal.h                 |   1 +
> >   fs/proc/task_mmu.c                 | 149 +++++++++++++++++++++++++++++++++++++
> >   include/linux/rmap.h               |   4 +
> >   mm/vmscan.c                        |  85 ++++++++++++++++-----
> >   6 files changed, 235 insertions(+), 20 deletions(-)
>
>
> .