[{"id":38941,"web_url":"https://patchwork.libcamera.org/comment/38941/","msgid":"<16daa914-a55e-4cbf-a2c4-5204aadb7c10@collabora.com>","date":"2026-05-21T16:36:54","subject":"Re: [PATCH v1 2/3] egl: Call glFlush before glFinish","submitter":{"id":140,"url":"https://patchwork.libcamera.org/api/people/140/","name":"Robert Mader","email":"robert.mader@collabora.com"},"content":"Opened a Mesa issue about this: \nhttps://gitlab.freedesktop.org/mesa/mesa/-/work_items/15516\n\nOn 21.05.26 16:10, Robert Mader wrote:\n> Apparently it is not guaranteed that drivers will do so implicitly,\n> which may or may not be a driver bug. The impact on performance has been\n> observed to be significant and it's easy enough, so let's do it\n> explicitly.\n>\n> Below are some benchmark results. All where done using postmarketOS edge\n> with updates from 21th May 2026 (Mesa 26.1.1). The mentioned pipelines\n> where run five times each, with the mean value included here, which should\n> be quite representive as the variance was rather small. All devices\n> where using the powersave governor.\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@1a -s width=1920,height=1080 --capture=60\n> Before: 47986 us/frame\n> After: 33596 us/frame !\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@1a -s width=1920,height=1080 --capture=60\n> Before: 30294 us/frame\n> After: 14922 us/frame !\n>\n> cam -c /base/soc@0/cci@ac4b000/i2c-bus@1/camera@10 -s width=1920,height=1080 --capture=60\n> Before: 27373 us/frame\n> After: 26106 us/frame\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@29 -s width=1920,height=1080 --capture=60\n> Before: 16339 us/frame\n> After: 15897 us/frame\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@10 -s width=1920,height=1080 --capture=60\n> Before: 26206 us/frame\n> After: 25721 us/frame\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@10 -s width=1920,height=1080 --capture=60\n> Before: 43723 us/frame\n> After: 34124 us/frame !\n>\n> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@1a -s width=1920,height=1080 --capture=60\n> Before: 23597 us/frame\n> After: 23707 us/frame\n>\n> cam -c /base/soc@0/bus@30800000/i2c@30a40000/camera@20 -s width=1280,height=720 --capture=60\n> Before: 91200 us/frame\n> After: 91649 us/frame\n>\n> cam -c /base/soc@0/bus@30800000/i2c@30a50000/camera@2d -s width=1280,height=720 --capture=60\n> Before: 76577 us/frame\n> After: 76956 us/frame\n>\n> cam -c /base/i2c-csi/front-camera@3c -s width=1280,height=720 --capture=60\n> Before: 188122 us/frame\n> After: 188500 us/frame\n>\n> cam -c /base/i2c-csi/rear-camera@4c -s width=1280,height=720 --capture=60\n> Before: 193712 us/frame\n> After: 190222 us/frame\n>\n> Signed-off-by: Robert Mader \n> ---\n> src/libcamera/egl.cpp | 1 +\n> 1 file changed, 1 insertion(+)\n>\n> diff --git a/src/libcamera/egl.cpp b/src/libcamera/egl.cpp\n> index 357918711..d9bc4f555 100644\n> --- a/src/libcamera/egl.cpp\n> +++ b/src/libcamera/egl.cpp\n> @@ -94,6 +94,7 @@ void eGL::syncOutput()\n> {\n> \tASSERT(tid_ == Thread::currentId());\n> \n> +\tglFlush();\n> \tglFinish();\n> }\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 28BDEBDCBC\n\tfor ;\n\tThu, 21 May 2026 16:37:05 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id EA64162FEC;\n\tThu, 21 May 2026 18:37:03 +0200 (CEST)","from sender4-op-o12.zoho.com (sender4-op-o12.zoho.com\n\t[136.143.188.12])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id EC00B62E6A\n\tfor ;\n\tThu, 21 May 2026 18:37:01 +0200 (CEST)","by mx.zohomail.com with SMTPS id 1779381417133538.3045711715414;\n\tThu, 21 May 2026 09:36:57 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; 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charset=UTF-8; format=flowed","Content-Transfer-Encoding":"7bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":38946,"web_url":"https://patchwork.libcamera.org/comment/38946/","msgid":"<463f714d-db90-4387-9f30-dafca521755d@collabora.com>","date":"2026-05-25T11:44:39","subject":"Re: [PATCH v1 2/3] egl: Call glFlush before glFinish","submitter":{"id":140,"url":"https://patchwork.libcamera.org/api/people/140/","name":"Robert Mader","email":"robert.mader@collabora.com"},"content":"It turned out that this patch just works around a driver bug (apparently \nscheduling related) and that running with `GALLIUM_THREAD=0` - i.e. \nnon-threaded GL driver - has the same positive impact. Thus I'll drop \nthe patch from v2 (the following patch reverts it anyway) and re-run the \nbenchmarks with `GALLIUM_THREAD=0`.\n\nWith that clarified I think this series should be ready to go and mostly \na non-brainer for merging. Thus quick question: does anyone reading this \nhave more remarks / suggestions? Maybe Bryan or Barnabás?\n\nOn 21.05.26 18:36, Robert Mader wrote:\n> Opened a Mesa issue about this: \n> https://gitlab.freedesktop.org/mesa/mesa/-/work_items/15516\n>\n> On 21.05.26 16:10, Robert Mader wrote:\n>> Apparently it is not guaranteed that drivers will do so implicitly,\n>> which may or may not be a driver bug. The impact on performance has been\n>> observed to be significant and it's easy enough, so let's do it\n>> explicitly.\n>>\n>> Below are some benchmark results. All where done using postmarketOS edge\n>> with updates from 21th May 2026 (Mesa 26.1.1). The mentioned pipelines\n>> where run five times each, with the mean value included here, which \n>> should\n>> be quite representive as the variance was rather small. All devices\n>> where using the powersave governor.\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@1a -s \n>> width=1920,height=1080 --capture=60\n>> Before: 47986 us/frame\n>> After: 33596 us/frame !\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@1a -s \n>> width=1920,height=1080 --capture=60\n>> Before: 30294 us/frame\n>> After: 14922 us/frame !\n>>\n>> cam -c /base/soc@0/cci@ac4b000/i2c-bus@1/camera@10 -s \n>> width=1920,height=1080 --capture=60\n>> Before: 27373 us/frame\n>> After: 26106 us/frame\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@29 -s \n>> width=1920,height=1080 --capture=60\n>> Before: 16339 us/frame\n>> After: 15897 us/frame\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@1/camera@10 -s \n>> width=1920,height=1080 --capture=60\n>> Before: 26206 us/frame\n>> After: 25721 us/frame\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@10 -s \n>> width=1920,height=1080 --capture=60\n>> Before: 43723 us/frame\n>> After: 34124 us/frame !\n>>\n>> cam -c /base/soc@0/cci@ac4a000/i2c-bus@0/camera@1a -s \n>> width=1920,height=1080 --capture=60\n>> Before: 23597 us/frame\n>> After: 23707 us/frame\n>>\n>> cam -c /base/soc@0/bus@30800000/i2c@30a40000/camera@20 -s \n>> width=1280,height=720 --capture=60\n>> Before: 91200 us/frame\n>> After: 91649 us/frame\n>>\n>> cam -c /base/soc@0/bus@30800000/i2c@30a50000/camera@2d -s \n>> width=1280,height=720 --capture=60\n>> Before: 76577 us/frame\n>> After: 76956 us/frame\n>>\n>> cam -c /base/i2c-csi/front-camera@3c -s width=1280,height=720 \n>> --capture=60\n>> Before: 188122 us/frame\n>> After: 188500 us/frame\n>>\n>> cam -c /base/i2c-csi/rear-camera@4c -s width=1280,height=720 \n>> --capture=60\n>> Before: 193712 us/frame\n>> After: 190222 us/frame\n>>\n>> Signed-off-by: Robert Mader \n>> ---\n>>   src/libcamera/egl.cpp | 1 +\n>>   1 file changed, 1 insertion(+)\n>>\n>> diff --git a/src/libcamera/egl.cpp b/src/libcamera/egl.cpp\n>> index 357918711..d9bc4f555 100644\n>> --- a/src/libcamera/egl.cpp\n>> +++ b/src/libcamera/egl.cpp\n>> @@ -94,6 +94,7 @@ void eGL::syncOutput()\n>>   {\n>>       ASSERT(tid_ == Thread::currentId());\n>>   +    glFlush();\n>>       glFinish();\n>>   }\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 3D555BDCBC\n\tfor ;\n\tMon, 25 May 2026 11:44:57 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 141326301A;\n\tMon, 25 May 2026 13:44:56 +0200 (CEST)","from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com\n\t[136.143.188.112])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 8149A62010\n\tfor ;\n\tMon, 25 May 2026 13:44:53 +0200 (CEST)","by mx.zohomail.com with SMTPS id 1779709487593302.0489075068713;\n\tMon, 25 May 2026 04:44:47 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; 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