Messages in this thread | | | From | <> | Subject | Re: [PATCH v2] riscv: enable THP_SWAP for RV64 | Date | Tue, 30 Aug 2022 14:26:38 +0000 |
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On 30/08/2022 15:15, Conor Dooley - M52691 wrote: > 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.
130k before & after.**
> > 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.
What I mean is: before/after the patch had visible performance difference because it was always flucuating in the same range.
> >> >> 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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