On 2016/2/17 8:35, David Rientjes wrote: > On Tue, 16 Feb 2016, Greg Kroah-Hartman wrote: > >> On Tue, Feb 16, 2016 at 05:37:05PM +0800, Xishi Qiu wrote: >>> Currently tasksize in lowmem_scan() only calculate rss, and not include swap. >>> But usually smart phones enable zram, so swap space actually use ram. >> >> Yes, but does that matter for this type of calculation? I need an ack >> from the android team before I could ever take such a core change to >> this code... >> > > The calculation proposed in this patch is the same as the generic oom > killer, it's an estimate of the amount of memory that will be freed if it > is killed and can exit. This is better than simply get_mm_rss(). > > However, I think we seriously need to re-consider the implementation of > the lowmem killer entirely. It currently abuses the use of TIF_MEMDIE, > which should ideally only be set for one thread on the system since it > allows unbounded access to global memory reserves. > Hi David, Does somebody do the work of re-implementation of the lowmem killer entirely now? Could you give me some details? e.g. when and how? Here are another two questions. 1) lmk has several lowmem thresholds, it's "lowmem_minfree[]", and the value is static definition, so is it reasonable for different memory size(e.g. 2G/3G/4G...) of smart phones? 2) There are many adjustable arguments in /proc/sys/vm/, and the default value maybe not benefit for smart phones, so any suggestions? Thanks, Xishi Qiu > It also abuses the user-visible /proc/self/oom_score_adj tunable: this > tunable is used by the generic oom killer to bias or discount a proportion > of memory from a process's usage. This is the only supported semantic of > the tunable. The lowmem killer uses it as a strict prioritization, so any > process with oom_score_adj higher than another process is preferred for > kill, REGARDLESS of memory usage. This leads to priority inversion, the > user is unable to always define the same process to be killed by the > generic oom killer and the lowmem killer. This is what happens when a > tunable with a very clear and defined purpose is used for other reasons. > > I'd seriously consider not accepting any additional hacks on top of this > code until the implementation is rewritten. > > . > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
