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FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_VIA_SMTP_AUTH(0.00)[]; FREEMAIL_CC(0.00)[redhat.com,ffwll.ch,gmx.de,microsoft.com,kernel.org,linux-foundation.org,lst.de,lists.freedesktop.org,vger.kernel.org,kvack.org]; RCVD_TLS_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo] X-Spam-Score: -4.51 X-Spam-Level: Hi Am 04.06.25 um 23:43 schrieb Michael Kelley: [...] > Nonetheless, there's an underlying issue. A main cause of the difference > is the number of messages to Hyper-V to update dirty regions. With > hyperv_fb using deferred I/O, the messages are limited 20/second, so > the total number of messages to Hyper-V is about 480. But hyperv_drm > appears to send 3 messages to Hyper-V for each line of output, or a total of > about 3,000,000 messages (~90K/second). That's a lot of additional load > on the Hyper-V host, and it adds the 10 seconds of additional elapsed > time seen in the guest. There also this ugly output in dmesg because the > ring buffer for sending messages to the Hyper-V host gets full -- Hyper-V > doesn't always keep up, at least not on my local laptop where I'm > testing: > > [12574.327615] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12574.327684] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12574.327760] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12574.327841] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12597.016128] hyperv_sendpacket: 6211 callbacks suppressed > [12597.016133] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12597.016172] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12597.016220] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > [12597.016267] hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] *ERROR* Unable to send packet via vmbus; error -11 > > hyperv_drm could be fixed to not output the ugly messages, but there's > still the underlying issue of overrunning the ring buffer, and excessively > hammering on the host. If we could get hyperv_drm doing deferred I/O, I > would feel much better about going full-on with deprecating hyperv_fb. I try to address the problem with the patches at https://lore.kernel.org/dri-devel/20250605152637.98493-1-tzimmermann@suse.de/ Testing and feedback is much appreciated. Best regards Thomas > > Michael > -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)