On 6/28/19 2:25 PM, Alexander Duyck wrote: > On Tue, Jun 25, 2019 at 10:32 AM Nitesh Narayan Lal <nitesh@xxxxxxxxxx> wrote: >> On 6/25/19 1:10 PM, Alexander Duyck wrote: >>> On Tue, Jun 25, 2019 at 7:49 AM Nitesh Narayan Lal <nitesh@xxxxxxxxxx> wrote: >>>> On 6/3/19 2:04 PM, Michael S. Tsirkin wrote: >>>>> On Mon, Jun 03, 2019 at 01:03:04PM -0400, Nitesh Narayan Lal wrote: >>>>>> This patch series proposes an efficient mechanism for communicating free memory >>>>>> from a guest to its hypervisor. It especially enables guests with no page cache >>>>>> (e.g., nvdimm, virtio-pmem) or with small page caches (e.g., ram > disk) to >>>>>> rapidly hand back free memory to the hypervisor. >>>>>> This approach has a minimal impact on the existing core-mm infrastructure. >>>>> Could you help us compare with Alex's series? >>>>> What are the main differences? >>>> Results on comparing the benefits/performance of Alexander's v1 >>>> (bubble-hinting)[1], Page-Hinting (includes some of the upstream >>>> suggested changes on v10) over an unmodified Kernel. >>>> >>>> Test1 - Number of guests that can be launched without swap usage. >>>> Guest size: 5GB >>>> Cores: 4 >>>> Total NUMA Node Memory ~ 15 GB (All guests are running on a single node) >>>> Process: Guest is launched sequentially after running an allocation >>>> program with 4GB request. >>>> >>>> Results: >>>> unmodified kernel: 2 guests without swap usage and 3rd guest with a swap >>>> usage of 2.3GB. >>>> bubble-hinting v1: 4 guests without swap usage and 5th guest with a swap >>>> usage of 1MB. >>>> Page-hinting: 5 guests without swap usage and 6th guest with a swap >>>> usage of 8MB. >>>> >>>> >>>> Test2 - Memhog execution time >>>> Guest size: 6GB >>>> Cores: 4 >>>> Total NUMA Node Memory ~ 15 GB (All guests are running on a single node) >>>> Process: 3 guests are launched and "time memhog 6G" is launched in each >>>> of them sequentially. >>>> >>>> Results: >>>> unmodified kernel: Guest1-40s, Guest2-1m5s, Guest3-6m38s (swap usage at >>>> the end-3.6G) >>>> bubble-hinting v1: Guest1-32s, Guest2-58s, Guest3-35s (swap usage at the >>>> end-0) >>>> Page-hinting: Guest1-42s, Guest2-47s, Guest3-32s (swap usage at the end-0) >>>> >>>> >>>> Test3 - Will-it-scale's page_fault1 >>>> Guest size: 6GB >>>> Cores: 24 >>>> Total NUMA Node Memory ~ 15 GB (All guests are running on a single node) >>>> >>>> unmodified kernel: >>>> tasks,processes,processes_idle,threads,threads_idle,linear >>>> 0,0,100,0,100,0 >>>> 1,459168,95.83,459315,95.83,459315 >>>> 2,956272,91.68,884643,91.72,918630 >>>> 3,1407811,87.53,1267948,87.69,1377945 >>>> 4,1755744,83.39,1562471,83.73,1837260 >>>> 5,2056741,79.24,1812309,80.00,2296575 >>>> 6,2393759,75.09,2025719,77.02,2755890 >>>> 7,2754403,70.95,2238180,73.72,3215205 >>>> 8,2947493,66.81,2369686,70.37,3674520 >>>> 9,3063579,62.68,2321148,68.84,4133835 >>>> 10,3229023,58.54,2377596,65.84,4593150 >>>> 11,3337665,54.40,2429818,64.01,5052465 >>>> 12,3255140,50.28,2395070,61.63,5511780 >>>> 13,3260721,46.11,2402644,59.77,5971095 >>>> 14,3210590,42.02,2390806,57.46,6430410 >>>> 15,3164811,37.88,2265352,51.39,6889725 >>>> 16,3144764,33.77,2335028,54.07,7349040 >>>> 17,3128839,29.63,2328662,49.52,7808355 >>>> 18,3133344,25.50,2301181,48.01,8267670 >>>> 19,3135979,21.38,2343003,43.66,8726985 >>>> 20,3136448,17.27,2306109,40.81,9186300 >>>> 21,3130324,13.16,2403688,35.84,9645615 >>>> 22,3109883,9.04,2290808,36.24,10104930 >>>> 23,3136805,4.94,2263818,35.43,10564245 >>>> 24,3118949,0.78,2252891,31.03,11023560 >>>> >>>> bubble-hinting v1: >>>> tasks,processes,processes_idle,threads,threads_idle,linear >>>> 0,0,100,0,100,0 >>>> 1,292183,95.83,292428,95.83,292428 >>>> 2,540606,91.67,501887,91.91,584856 >>>> 3,821748,87.53,735244,88.31,877284 >>>> 4,1033782,83.38,839925,85.59,1169712 >>>> 5,1261352,79.25,896464,83.86,1462140 >>>> 6,1459544,75.12,1050094,80.93,1754568 >>>> 7,1686537,70.97,1112202,79.23,2046996 >>>> 8,1866892,66.83,1083571,78.48,2339424 >>>> 9,2056887,62.72,1101660,77.94,2631852 >>>> 10,2252955,58.57,1097439,77.36,2924280 >>>> 11,2413907,54.40,1088583,76.72,3216708 >>>> 12,2596504,50.35,1117474,76.01,3509136 >>>> 13,2715338,46.21,1087666,75.32,3801564 >>>> 14,2861697,42.08,1084692,74.35,4093992 >>>> 15,2964620,38.02,1087910,73.40,4386420 >>>> 16,3065575,33.84,1099406,71.07,4678848 >>>> 17,3107674,29.76,1056948,71.36,4971276 >>>> 18,3144963,25.71,1094883,70.14,5263704 >>>> 19,3173468,21.61,1073049,66.21,5556132 >>>> 20,3173233,17.55,1072417,67.16,5848560 >>>> 21,3209710,13.37,1079147,65.64,6140988 >>>> 22,3182958,9.37,1085872,65.95,6433416 >>>> 23,3200747,5.23,1076414,59.40,6725844 >>>> 24,3181699,1.04,1051233,65.62,7018272 >>>> >>>> Page-hinting: >>>> tasks,processes,processes_idle,threads,threads_idle,linear >>>> 0,0,100,0,100,0 >>>> 1,467693,95.83,467970,95.83,467970 >>>> 2,967860,91.68,895883,91.70,935940 >>>> 3,1408191,87.53,1279602,87.68,1403910 >>>> 4,1766250,83.39,1557224,83.93,1871880 >>>> 5,2124689,79.24,1834625,80.35,2339850 >>>> 6,2413514,75.10,1989557,77.00,2807820 >>>> 7,2644648,70.95,2158055,73.73,3275790 >>>> 8,2896483,66.81,2305785,70.85,3743760 >>>> 9,3157796,62.67,2304083,69.49,4211730 >>>> 10,3251633,58.53,2379589,66.43,4679700 >>>> 11,3313704,54.41,2349310,64.76,5147670 >>>> 12,3285612,50.30,2362013,62.63,5615640 >>>> 13,3207275,46.17,2377760,59.94,6083610 >>>> 14,3221727,42.02,2416278,56.70,6551580 >>>> 15,3194781,37.91,2334552,54.96,7019550 >>>> 16,3211818,33.78,2399077,52.75,7487520 >>>> 17,3172664,29.65,2337660,50.27,7955490 >>>> 18,3177152,25.49,2349721,47.02,8423460 >>>> 19,3149924,21.36,2319286,40.16,8891430 >>>> 20,3166910,17.30,2279719,43.23,9359400 >>>> 21,3159464,13.19,2342849,34.84,9827370 >>>> 22,3167091,9.06,2285156,37.97,10295340 >>>> 23,3174137,4.96,2365448,33.74,10763310 >>>> 24,3161629,0.86,2253813,32.38,11231280 >>>> >>>> >>>> Test4: Netperf >>>> Guest size: 5GB >>>> Cores: 4 >>>> Total NUMA Node Memory ~ 15 GB (All guests are running on a single node) >>>> Netserver: Running on core 0 >>>> Netperf: Running on core 1 >>>> Recv Socket Size bytes: 131072 >>>> Send Socket Size bytes:16384 >>>> Send Message Size bytes:1000000000 >>>> Time: 900s >>>> Process: netperf is run 3 times sequentially in the same guest with the >>>> same inputs mentioned above and throughput (10^6bits/sec) is observed. >>>> unmodified kernel: 1st Run-14769.60, 2nd Run-14849.18, 3rd Run-14842.02 >>>> bubble-hinting v1: 1st Run-13441.77, 2nd Run-13487.81, 3rd Run-13503.87 >>>> Page-hinting: 1st Run-14308.20, 2nd Run-14344.36, 3rd Run-14450.07 >>>> >>>> Drawback with bubble-hinting: >>>> More invasive. >>>> >>>> Drawback with page-hinting: >>>> Additional bitmap required, including growing/shrinking the bitmap on >>>> memory hotplug. >>>> >>>> >>>> [1] https://lkml.org/lkml/2019/6/19/926 >>> Any chance you could provide a .config for your kernel? I'm wondering >>> what is different between the two as it seems like you are showing a >>> significant regression in terms of performance for the bubble >>> hinting/aeration approach versus a stock kernel without the patches >>> and that doesn't match up with what I have been seeing. >> I have attached the config which I was using. > Were all of these runs with the same config? I ask because I noticed > the config you provided had a number of quite expensive memory debug > options enabled: Yes, memory debugging configs were enabled for all the cases. > > # > # Memory Debugging > # > CONFIG_PAGE_EXTENSION=y > CONFIG_DEBUG_PAGEALLOC=y > CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT=y > CONFIG_PAGE_OWNER=y > # CONFIG_PAGE_POISONING is not set > CONFIG_DEBUG_PAGE_REF=y > # CONFIG_DEBUG_RODATA_TEST is not set > CONFIG_DEBUG_OBJECTS=y > # CONFIG_DEBUG_OBJECTS_SELFTEST is not set > # CONFIG_DEBUG_OBJECTS_FREE is not set > # CONFIG_DEBUG_OBJECTS_TIMERS is not set > # CONFIG_DEBUG_OBJECTS_WORK is not set > # CONFIG_DEBUG_OBJECTS_RCU_HEAD is not set > # CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER is not set > CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1 > CONFIG_SLUB_DEBUG_ON=y > # CONFIG_SLUB_STATS is not set > CONFIG_HAVE_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=400 > # CONFIG_DEBUG_KMEMLEAK_TEST is not set > # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set > CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y > CONFIG_DEBUG_STACK_USAGE=y > CONFIG_DEBUG_VM=y > # CONFIG_DEBUG_VM_VMACACHE is not set > # CONFIG_DEBUG_VM_RB is not set > # CONFIG_DEBUG_VM_PGFLAGS is not set > CONFIG_ARCH_HAS_DEBUG_VIRTUAL=y > CONFIG_DEBUG_VIRTUAL=y > CONFIG_DEBUG_MEMORY_INIT=y > CONFIG_DEBUG_PER_CPU_MAPS=y > CONFIG_HAVE_ARCH_KASAN=y > CONFIG_CC_HAS_KASAN_GENERIC=y > # CONFIG_KASAN is not set > CONFIG_KASAN_STACK=1 > # end of Memory Debugging > > When I went through and enabled these then my results for the bubble > hinting matched pretty closely to what you reported. However, when I > compiled without the patches and this config enabled the results were > still about what was reported with the bubble hinting but were maybe > 5% improved. I'm just wondering if you were doing some additional > debugging and left those options enabled for the bubble hinting test > run. I have the same set of debugging options enabled for all three cases reported. -- Thanks Nitesh
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