Messages in this thread | | | From | <> | Subject | Re: [PATCH v2] riscv: enable THP_SWAP for RV64 | Date | Tue, 30 Aug 2022 14:15:45 +0000 |
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On 30/08/2022 14:59, Jisheng Zhang wrote: > On Mon, Aug 29, 2022 at 05:27:48PM +0000, Conor.Dooley@microchip.com wrote: >> On 29/08/2022 15:10, Jisheng Zhang wrote: >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> On Sat, Aug 27, 2022 at 09:13:03PM +0000, Conor.Dooley@microchip.com wrote: >>>> Hey Jisheng, >>> >>> Hi Conor, >>> >>>> On 27/08/2022 10:58, Jisheng Zhang wrote: >>>>> I have a Sipeed Lichee RV dock board which only has 512MB DDR, so >>>>> memory optimizations such as swap on zram are helpful. As is seen >>>>> in commit d0637c505f8a ("arm64: enable THP_SWAP for arm64") and >>>>> commit bd4c82c22c367e ("mm, THP, swap: delay splitting THP after >>>>> swapped out"), THP_SWAP can improve the swap throughput significantly. >>>>> >>>>> Enable THP_SWAP for RV64, testing the micro-benchmark which is >>>>> introduced by commit d0637c505f8a ("arm64: enable THP_SWAP for arm64") >>>>> shows below numbers on the Lichee RV dock board: >>>>> >>>>> thp swp throughput w/o patch: 66908 bytes/ms (mean of 10 tests) >>>>> thp swp throughput w/ patch: 322638 bytes/ms (mean of 10 tests) >>>> >>>> I know the original commit message contains this, but it's a little >>>> odd. If the patch /enables/ THP then how would there be THP swap >>>> prior to the patch? >>> >>> hmm, it's swap I'll send a v3 to correct the description. >>> >>>> >>>>> >>>>> Improved by 382%! >>>> >>>> I could not replicate the after numbers on my nezha, so I suspect >>>> I am missing something in my config/setup. zswap is enabled and is >>> >>> swap on zram rather than zswap ;) >> >> I think I tried about 30 different config variations, initially not >> using zswap and later using it. >> My zramctl looks like so (although I did try zstd too) after running >> the demo application from that commit: >> >> NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT >> /dev/zram0 lzo-rle 241M 22M 8.4M 9.1M 1 [SWAP] >> >> I am using the default riscv defconfig + the following: >> CONFIG_ZRAM=y >> CONFIG_CRYPTO_DEFLATE=y >> CONFIG_CRYPTO_LZO=y >> CONFIG_CRYPTO_ZSTD=y >> CONFIG_ZRAM_MEMORY_TRACKING=y >> CONFIG_TRANSPARENT_HUGEPAGE=y >> CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y >> CONFIG_THP_SWAP=y >> >> Am I just missing something obvious here? > > similar config options here. what's your rootfs? Is your board busy > with something? I used a minimal rootfs built from buildroot. > can you plz show your numbers w/ and w/o the patch?
I was using fedora for the testing, downloaded directly from koji. My before/after numbers varied, but were around 80,000 bytes/ms most of the time.
If I increased the size to 500 * 1024 * 1024 I got around 130k.
Before/after the patch, the numbers did not really change, but things did fluctuate quite wildly - from about 50k to 90k using the 400 size.
> > I also tried the simple benchmark on qemu(just for reference, since > I have no other riscv boards except the lichee RV dock board): > swp out w/o patch: 30066 bytes/ms (mean of 10 tests) > swp out w/ patch: 130055 bytes/ms (mean of 10 tests) > so improved by 332.7%
I'll give QEMU a go so :)
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