Messages in this thread | | | Date | Wed, 14 Jan 2009 15:45:35 +0900 | From | "MinChan Kim" <> | Subject | Re: lowmemory android driver not needed? |
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Hi, Arve.
On Wed, Jan 14, 2009 at 11:30 AM, Arve Hjønnevåg <arve@android.com> wrote: > The oom killer does not kick in until all caches are emptied. Our user > space code changes the oom_adj value of processes that are no longer > in the foreground so that they killed first (the process saves its > state but does not exit). To avoid excessive demand paging, the low > memory killer will kill these processes when the memory available > drops below a threshold.
It have some problems. (drivers/staging/android/lwmemorykiller.c)
1. lowmem_shrink function have to answer about vm's query the cache size fast. 2. it don't consider page size and memory size when it make lowmem_minfree's values. 3. If system have many processes, for_each_process take a long time. it may result system latency although lowmemkiller intend to avoid latency. 4. Most important thing. Could we use memory controller instead of lowmemkiller ? I am not sure since I don't follow up memory controller in these days.
I think we have to use existing facility if possible. Previously, There are similar kinds of patches. but It can't merge mainline due to some issue. They can comment about lowmemkiller. I will CC them.
> -- > Arve Hjønnevåg > > > On Tue, Jan 13, 2009 at 6:18 PM, Brian Swetland <swetland@google.com> wrote: >> >> Looping in Arve who wrote the low memory killer and can explain things >> in more detail. >> >> Brian >> >> [Greg KH <greg@kroah.com>] >>> Hi San, >>> >>> Alan Cox pointed me at the /proc/<pid>/oom_adj file that controls the >>> oom-killer score for any process as being more than sufficent to control >>> the oom killer. >>> >>> This makes me wonder why you wrote the android lowmemlorykiller driver? >>> >>> What is that driver for that is not already present in the existing >>> oom_* values for every process? >>> >>> thanks, >>> >>> greg k-h >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
-- Kinds regards, MinChan Kim
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