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
