Messages in this thread | | | Date | Tue, 24 Oct 2023 15:21:38 +0800 | Subject | Re: [PATCH v2 1/2] mm:vmscan: the dirty folio in folio_list skip unmap | From | zhiguojiang <> |
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在 2023/10/24 15:07, David Hildenbrand 写道: > On 24.10.23 04:04, zhiguojiang wrote: >> >> >> 在 2023/10/23 21:01, Matthew Wilcox 写道: >>> On Mon, Oct 23, 2023 at 08:44:55PM +0800, zhiguojiang wrote: >>>> 在 2023/10/23 20:21, Matthew Wilcox 写道: >>>>> On Mon, Oct 23, 2023 at 04:07:28PM +0800, zhiguojiang wrote: >>>>>>> Are you seeing measurable changes for any workloads? It >>>>>>> certainly seems >>>>>>> like you should, but it would help if you chose a test from >>>>>>> mmtests and >>>>>>> showed how performance changed on your system. >>>>>> In one mmtest, the max times for a invalid recyling of a >>>>>> folio_list dirty >>>>>> folio that does not support pageout and has been activated in >>>>>> shrink_folio_list() are: cost=51us, exe=2365us. >>>>>> >>>>>> Calculate according to this formula: dirty_cost / total_cost * >>>>>> 100%, the >>>>>> recyling efficiency of dirty folios can be improved 53.13%、82.95%. >>>>>> >>>>>> So this patch can optimize shrink efficiency and reduce the >>>>>> workload of >>>>>> kswapd to a certain extent. >>>>>> >>>>>> kswapd0-96 ( 96) [005] ..... 387.218548: >>>>>> mm_vmscan_lru_shrink_inactive: [Justin] nid 0 nr_scanned 32 >>>>>> nr_taken 32 >>>>>> nr_reclaimed 31 nr_dirty 1 nr_unqueued_dirty 1 nr_writeback 0 >>>>>> nr_activate[1] 1 nr_ref_keep 0 f RECLAIM_WB_FILE|RECLAIM_WB_ASYNC >>>>>> total_cost 96 total_exe 2365 dirty_cost 51 total_exe 2365 >>>>>> >>>>>> kswapd0-96 ( 96) [006] ..... 412.822532: >>>>>> mm_vmscan_lru_shrink_inactive: [Justin] nid 0 nr_scanned 32 >>>>>> nr_taken 32 >>>>>> nr_reclaimed 0 nr_dirty 32 nr_unqueued_dirty 32 nr_writeback 0 >>>>>> nr_activate[1] 19 nr_ref_keep 13 f RECLAIM_WB_FILE|RECLAIM_WB_ASYNC >>>>>> total_cost 88 total_exe 605 dirty_cost 73 total_exe 605 >>>>> I appreciate that you can put probes in and determine the cost, >>>>> but do >>>>> you see improvements for a real workload? Like doing a kernel >>>>> compile >>>>> -- does it speed up at all? >>>> Can you help share a method for testing thread workload, like kswapd? >>> Something dirt simple like 'time make -j8'. >> Two compilations were conducted separately, and compared to the >> unmodified compilation, >> the compilation time for adding modified patches had a certain >> reduction, as follows: >> >> Compilation command: >> make distclean -j8 >> make ARCH=x86_64 x86_64_defconfig >> time make -j8 >> >> 1.Unmodified Compilation time: >> real 2m40.276s >> user 16m2.956s >> sys 2m14.738s >> >> real 2m40.136s >> user 16m2.617s >> sys 2m14.722s >> >> 2.[Patch v2 1/2] Modified Compilation time: >> real 2m40.067s >> user 16m3.164s >> sys 2m14.211s >> >> real 2m40.123s >> user 16m2.439s >> sys 2m14.508s >> >> 3 [Patch v2 1/2] + [Patch v2 2/2] Modified Compilation time: >> real 2m40.367s >> user 16m3.738s >> sys 2m13.662s >> >> real 2m40.014s >> user 16m3.108s >> sys 2m14.096s >> > > To get expressive numbers two iterations are usually not sufficient. > How much memory does you system have? Does vmscan even ever get active? Test system memory: MemTotal: 8161608 kB. When multiple Apps were opened, vmscan can get active. I can capture a lot of tracelog data through testing, I only posted two sets of tracelog data.
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