Hi Feng, do you still have the test setup that produced the performance penalty? If so, could you give a try to the patchset at [1]? I think I've fixed the remaining issues in earlier versions and I'd like to see if it actually improves performance. Best regards Thomas [1] https://lists.freedesktop.org/archives/dri-devel/2019-December/247771.html Am 05.08.19 um 14:52 schrieb Feng Tang: > Hi Thomas, > > On Mon, Aug 05, 2019 at 12:22:11PM +0200, Thomas Zimmermann wrote: > > [snip] > >>>> 2019-08-03 19:29:17 ./case-anon-cow-seq-hugetlb >>>> 2019-08-03 19:29:17 ./usemem --runtime 300 -n 4 --prealloc --prefault >>>> -O -U 815394406 >>>> 917318700 bytes / 659419 usecs = 1358497 KB/s >>>> 917318700 bytes / 659658 usecs = 1358005 KB/s >>>> 917318700 bytes / 659916 usecs = 1357474 KB/s >>>> 917318700 bytes / 660168 usecs = 1356956 KB/s >>>> >>>> Rong, Feng, could you confirm this by disabling the cursor or blinking? >>> >>> Glad to know this method restored the drop. Rong is running the case. >>> >>> While I have another finds, as I noticed your patch changed the bpp from >>> 24 to 32, I had a patch to change it back to 24, and run the case in >>> the weekend, the -18% regrssion was reduced to about -5%. Could this >>> be related? >> >> In the original code, the fbdev console already ran with 32 bpp [1] and >> 16 bpp was selected for low-end devices. [2][3] The patch only set the >> same values for userspace; nothing changed for the console. > > I did the experiment becasue I checked the commit > > 90f479ae51afa4 drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation > > in which there is code: > > diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c > index b10f726..a977333 100644 > --- a/drivers/gpu/drm/mgag200/mgag200_main.c > +++ b/drivers/gpu/drm/mgag200/mgag200_main.c > @@ -162,7 +162,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags) > if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024)) > dev->mode_config.preferred_depth = 16; > else > - dev->mode_config.preferred_depth = 24; > + dev->mode_config.preferred_depth = 32; > dev->mode_config.prefer_shadow = 1; > > My debug patch was kind of restoring of this part. > > Thanks, > Feng > >> >> Best regards >> Thomas >> >> [1] >> https://cgit.freedesktop.org/drm/drm-tip/tree/drivers/gpu/drm/mgag200/mgag200_fb.c?id=5d17718997367c435dbe5341a8e270d9b19478d3#n259 >> [2] >> https://cgit.freedesktop.org/drm/drm-tip/tree/drivers/gpu/drm/mgag200/mgag200_fb.c?id=5d17718997367c435dbe5341a8e270d9b19478d3#n263 >> [3] >> https://cgit.freedesktop.org/drm/drm-tip/tree/drivers/gpu/drm/mgag200/mgag200_fb.c?id=5d17718997367c435dbe5341a8e270d9b19478d3#n286 >> >>> >>> commit: >>> f1f8555dfb9 drm/bochs: Use shadow buffer for bochs framebuffer console >>> 90f479ae51a drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation >>> 01e75fea0d5 mgag200: restore the depth back to 24 >>> >>> f1f8555dfb9a70a2 90f479ae51afa45efab97afdde9 01e75fea0d5ff39d3e588c20ec5 >>> ---------------- --------------------------- --------------------------- >>> 43921 ± 2% -18.3% 35884 -4.8% 41826 vm-scalability.median >>> 14889337 -17.5% 12291029 -4.1% 14278574 vm-scalability.throughput >>> >>> commit 01e75fea0d5ff39d3e588c20ec52e7a4e6588a74 >>> Author: Feng Tang <feng.tang@xxxxxxxxx> >>> Date: Fri Aug 2 15:09:19 2019 +0800 >>> >>> mgag200: restore the depth back to 24 >>> >>> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx> >>> >>> diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c >>> index a977333..ac8f6c9 100644 >>> --- a/drivers/gpu/drm/mgag200/mgag200_main.c >>> +++ b/drivers/gpu/drm/mgag200/mgag200_main.c >>> @@ -162,7 +162,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags) >>> if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024)) >>> dev->mode_config.preferred_depth = 16; >>> else >>> - dev->mode_config.preferred_depth = 32; >>> + dev->mode_config.preferred_depth = 24;> dev->mode_config.prefer_shadow = 1; >>> >>> r = mgag200_modeset_init(mdev); >>> >>> Thanks, >>> Feng >>> >>>> >>>> >>>> The difference between mgag200's original fbdev support and generic >>>> fbdev emulation is generic fbdev's worker task that updates the VRAM >>>> buffer from the shadow buffer. mgag200 does this immediately, but relies >>>> on drm_can_sleep(), which is deprecated. >>>> >>>> I think that the worker task interferes with the test case, as the >>>> worker has been in fbdev emulation since forever and no performance >>>> regressions have been reported so far. >>>> >>>> >>>> So unless there's a report where this problem happens in a real-world >>>> use case, I'd like to keep code as it is. And apparently there's always >>>> the workaround of disabling the cursor blinking. >>>> >>>> Best regards >>>> Thomas >>>> >> >> -- >> Thomas Zimmermann >> Graphics Driver Developer >> SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany >> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah >> HRB 21284 (AG Nürnberg) >> > > > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel > -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer
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