[{"id":37872,"web_url":"https://patchwork.libcamera.org/comment/37872/","msgid":"<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-01-22T13:36:23","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Hi Barnabás,\n\nthank you for the patch.\n\nBarnabás Pőcze writes:\n\n> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n> `DebayerParams` object is copied multiple time:\n>\n> (1) call of `BoundMethodMember<...>::activate()`\n> inside `Object::invokeMethod()`\n> (2) constructor of `BoundMethodArgs<...>`\n> inside `BoundMethodMember<...>::activate()`\n> (3) call of `BoundMethodMember<...>::invoke()`\n> inside `BoundMethodArgs::invokePack()`\n> (4) call of the actual pointer to member function\n> inside `BoundMethodMember::invoke()`\n>\n> Given that the type has a size of 5696 bytes at the moment on x86-64,\n> while the size is expected to shrink considerably and compilers might\n> avoid one or two of the above copies, this is still not ideal. By making\n> `Debayer::process()` take the parameter object by const lvalue reference,\n> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n\nWhy RFC? Looks like harmless cleanup.\n\nReviewed-by: Milan Zamazal \n\n> Signed-off-by: Barnabás Pőcze \n> ---\n> src/libcamera/software_isp/debayer.cpp | 2 +-\n> src/libcamera/software_isp/debayer.h | 4 ++--\n> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n> 6 files changed, 11 insertions(+), 11 deletions(-)\n>\n> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n> index 65a1762dd..3e7702525 100644\n> --- a/src/libcamera/software_isp/debayer.cpp\n> +++ b/src/libcamera/software_isp/debayer.cpp\n> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n> * \\brief Select the bayer params to use for the next frame debayer\n> * \\param[in] params The parameters to be used in debayering\n> */\n> -void Debayer::setParams(DebayerParams ¶ms)\n> +void Debayer::setParams(const DebayerParams ¶ms)\n> {\n> \tgreen_ = params.green;\n> \tgreenCcm_ = params.greenCcm;\n> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n> index cd2db9930..99e22ed85 100644\n> --- a/src/libcamera/software_isp/debayer.h\n> +++ b/src/libcamera/software_isp/debayer.h\n> @@ -47,7 +47,7 @@ public:\n> \tvirtual std::tuple\n> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n> \n> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params) = 0;\n> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n> \tvirtual int start() { return 0; }\n> \tvirtual void stop() {}\n> \n> @@ -92,7 +92,7 @@ private:\n> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n> \n> protected:\n> -\tvoid setParams(DebayerParams ¶ms);\n> +\tvoid setParams(const DebayerParams ¶ms);\n> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\n> };\n> diff --git a/src/libcamera/software_isp/debayer_cpu.cpp b/src/libcamera/software_isp/debayer_cpu.cpp\n> index 00738c56b..b52f4d5c7 100644\n> --- a/src/libcamera/software_isp/debayer_cpu.cpp\n> +++ b/src/libcamera/software_isp/debayer_cpu.cpp\n> @@ -740,7 +740,7 @@ void DebayerCpu::process4(uint32_t frame, const uint8_t *src, uint8_t *dst)\n> \t}\n> }\n> \n> -void DebayerCpu::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params)\n> +void DebayerCpu::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms)\n> {\n> \tbench_.startFrame();\n> \n> diff --git a/src/libcamera/software_isp/debayer_cpu.h b/src/libcamera/software_isp/debayer_cpu.h\n> index 67df2b93a..27eff021d 100644\n> --- a/src/libcamera/software_isp/debayer_cpu.h\n> +++ b/src/libcamera/software_isp/debayer_cpu.h\n> @@ -37,7 +37,7 @@ public:\n> \tstd::vector formats(PixelFormat input);\n> \tstd::tuple\n> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size);\n> -\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params);\n> +\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms);\n> \tSizeRange sizes(PixelFormat inputFormat, const Size &inputSize);\n> \tconst SharedFD &getStatsFD() { return stats_->getStatsFD(); }\n> \n> diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp\n> index 9693d7252..1ac162427 100644\n> --- a/src/libcamera/software_isp/debayer_egl.cpp\n> +++ b/src/libcamera/software_isp/debayer_egl.cpp\n> @@ -386,7 +386,7 @@ DebayerEGL::strideAndFrameSize(const PixelFormat &outputFormat, const Size &size\n> \treturn std::make_tuple(stride, stride * size.height);\n> }\n> \n> -void DebayerEGL::setShaderVariableValues(DebayerParams ¶ms)\n> +void DebayerEGL::setShaderVariableValues(const DebayerParams ¶ms)\n> {\n> \t/*\n> \t * Raw Bayer 8-bit, and packed raw Bayer 10-bit/12-bit formats\n> @@ -509,7 +509,7 @@ void DebayerEGL::setShaderVariableValues(DebayerParams ¶ms)\n> \treturn;\n> }\n> \n> -int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams ¶ms)\n> +int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms)\n> {\n> \t/* eGL context switch */\n> \tegl_.makeCurrent();\n> @@ -536,7 +536,7 @@ int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams &par\n> \treturn 0;\n> }\n> \n> -void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params)\n> +void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms)\n> {\n> \tbench_.startFrame();\n> \n> diff --git a/src/libcamera/software_isp/debayer_egl.h b/src/libcamera/software_isp/debayer_egl.h\n> index a5033bc63..790348249 100644\n> --- a/src/libcamera/software_isp/debayer_egl.h\n> +++ b/src/libcamera/software_isp/debayer_egl.h\n> @@ -50,7 +50,7 @@ public:\n> \tstd::vector formats(PixelFormat input);\n> \tstd::tuple strideAndFrameSize(const PixelFormat &outputFormat, const Size &size);\n> \n> -\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params);\n> +\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms);\n> \tint start();\n> \tvoid stop();\n> \n> @@ -72,9 +72,9 @@ private:\n> \t\t\t\t std::vector shaderEnv);\n> \tint linkShaderProgram(void);\n> \tint getShaderVariableLocations();\n> -\tvoid setShaderVariableValues(DebayerParams ¶ms);\n> +\tvoid setShaderVariableValues(const DebayerParams ¶ms);\n> \tvoid configureTexture(GLuint &texture);\n> -\tint debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams ¶ms);\n> +\tint debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms);\n> \n> \t/* Shader program identifiers */\n> \tGLuint vertexShaderId_ = 0;","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 0BB98C3220\n\tfor ;\n\tThu, 22 Jan 2026 13:36:32 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 3CD0F61FC7;\n\tThu, 22 Jan 2026 14:36:31 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id C1E4C61F84\n\tfor ;\n\tThu, 22 Jan 2026 14:36:29 +0100 (CET)","from mail-wm1-f72.google.com (mail-wm1-f72.google.com\n\t[209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-127-STZP8dpFPweJC2PE6ZYIhQ-1; 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\n\tThu, 22 Jan 2026 05:36:25 -0800 (PST)","by 2002:a05:600c:3b90:b0:471:700:f281 with SMTP id\n\t5b1f17b1804b1-4803e7f0d72mr144022935e9.25.1769088984858; \n\tThu, 22 Jan 2026 05:36:24 -0800 (PST)"],"From":"Milan Zamazal ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","In-Reply-To":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com> (\n\t=?utf-8?b?IkJhcm5hYsOhcyBQxZFjemUiJ3M=?= message of \"Tue,\n\t20 Jan 2026 18:07:01 +0100\")","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>","Date":"Thu, 22 Jan 2026 14:36:23 +0100","Message-ID":"<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"-MPSHYxhaLhP2GXfq9FJNREm04UKYYKNBtpu1gLNd3E_1769088986","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable","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":37874,"web_url":"https://patchwork.libcamera.org/comment/37874/","msgid":"<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-01-22T13:46:42","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Milan Zamazal writes:\n\n> Hi Barnabás,\n>\n> thank you for the patch.\n>\n> Barnabás Pőcze writes:\n>\n>> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n>> `DebayerParams` object is copied multiple time:\n>>\n>> (1) call of `BoundMethodMember<...>::activate()`\n>> inside `Object::invokeMethod()`\n>> (2) constructor of `BoundMethodArgs<...>`\n>> inside `BoundMethodMember<...>::activate()`\n>> (3) call of `BoundMethodMember<...>::invoke()`\n>> inside `BoundMethodArgs::invokePack()`\n>> (4) call of the actual pointer to member function\n>> inside `BoundMethodMember::invoke()`\n>>\n>> Given that the type has a size of 5696 bytes at the moment on x86-64,\n>> while the size is expected to shrink considerably and compilers might\n>> avoid one or two of the above copies, this is still not ideal. By making\n>> `Debayer::process()` take the parameter object by const lvalue reference,\n>> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n>\n> Why RFC? Looks like harmless cleanup.\n>\n> Reviewed-by: Milan Zamazal \n>\n>> Signed-off-by: Barnabás Pőcze \n>> ---\n>> src/libcamera/software_isp/debayer.cpp | 2 +-\n>> src/libcamera/software_isp/debayer.h | 4 ++--\n>> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n>> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n>> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n>> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n>> 6 files changed, 11 insertions(+), 11 deletions(-)\n>>\n>> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n>> index 65a1762dd..3e7702525 100644\n>> --- a/src/libcamera/software_isp/debayer.cpp\n>> +++ b/src/libcamera/software_isp/debayer.cpp\n>> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n>> * \\brief Select the bayer params to use for the next frame debayer\n>> * \\param[in] params The parameters to be used in debayering\n>> */\n>> -void Debayer::setParams(DebayerParams ¶ms)\n>> +void Debayer::setParams(const DebayerParams ¶ms)\n>> {\n>> \tgreen_ = params.green;\n>> \tgreenCcm_ = params.greenCcm;\n>> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n>> index cd2db9930..99e22ed85 100644\n>> --- a/src/libcamera/software_isp/debayer.h\n>> +++ b/src/libcamera/software_isp/debayer.h\n>> @@ -47,7 +47,7 @@ public:\n>> \tvirtual std::tuple\n>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n>> \n>> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params) = 0;\n>> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n\nWell, this looks risky and I think it's better to avoid.\n\n>> \tvirtual int start() { return 0; }\n>> \tvirtual void stop() {}\n>> \n>> @@ -92,7 +92,7 @@ private:\n>> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n>> \n>> protected:\n>> -\tvoid setParams(DebayerParams ¶ms);\n>> +\tvoid setParams(const DebayerParams ¶ms);\n>> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n>> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\n>> };\n>> diff --git a/src/libcamera/software_isp/debayer_cpu.cpp b/src/libcamera/software_isp/debayer_cpu.cpp\n>> index 00738c56b..b52f4d5c7 100644\n>> --- a/src/libcamera/software_isp/debayer_cpu.cpp\n>> +++ b/src/libcamera/software_isp/debayer_cpu.cpp\n>> @@ -740,7 +740,7 @@ void DebayerCpu::process4(uint32_t frame, const uint8_t *src, uint8_t *dst)\n>> \t}\n>> }\n>> \n>> -void DebayerCpu::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params)\n>> +void DebayerCpu::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms)\n>> {\n>> \tbench_.startFrame();\n>> \n>> diff --git a/src/libcamera/software_isp/debayer_cpu.h b/src/libcamera/software_isp/debayer_cpu.h\n>> index 67df2b93a..27eff021d 100644\n>> --- a/src/libcamera/software_isp/debayer_cpu.h\n>> +++ b/src/libcamera/software_isp/debayer_cpu.h\n>> @@ -37,7 +37,7 @@ public:\n>> \tstd::vector formats(PixelFormat input);\n>> \tstd::tuple\n>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size);\n>> -\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params);\n>> +\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms);\n>> \tSizeRange sizes(PixelFormat inputFormat, const Size &inputSize);\n>> \tconst SharedFD &getStatsFD() { return stats_->getStatsFD(); }\n>> \n>> diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp\n>> index 9693d7252..1ac162427 100644\n>> --- a/src/libcamera/software_isp/debayer_egl.cpp\n>> +++ b/src/libcamera/software_isp/debayer_egl.cpp\n>> @@ -386,7 +386,7 @@ DebayerEGL::strideAndFrameSize(const PixelFormat &outputFormat, const Size &size\n>> \treturn std::make_tuple(stride, stride * size.height);\n>> }\n>> \n>> -void DebayerEGL::setShaderVariableValues(DebayerParams ¶ms)\n>> +void DebayerEGL::setShaderVariableValues(const DebayerParams ¶ms)\n>> {\n>> \t/*\n>> \t * Raw Bayer 8-bit, and packed raw Bayer 10-bit/12-bit formats\n>> @@ -509,7 +509,7 @@ void DebayerEGL::setShaderVariableValues(DebayerParams ¶ms)\n>> \treturn;\n>> }\n>> \n>> -int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams ¶ms)\n>> +int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms)\n>> {\n>> \t/* eGL context switch */\n>> \tegl_.makeCurrent();\n>> @@ -536,7 +536,7 @@ int DebayerEGL::debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams &par\n>> \treturn 0;\n>> }\n>> \n>> -void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params)\n>> +void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms)\n>> {\n>> \tbench_.startFrame();\n>> \n>> diff --git a/src/libcamera/software_isp/debayer_egl.h b/src/libcamera/software_isp/debayer_egl.h\n>> index a5033bc63..790348249 100644\n>> --- a/src/libcamera/software_isp/debayer_egl.h\n>> +++ b/src/libcamera/software_isp/debayer_egl.h\n>> @@ -50,7 +50,7 @@ public:\n>> \tstd::vector formats(PixelFormat input);\n>> \tstd::tuple strideAndFrameSize(const PixelFormat &outputFormat, const Size &size);\n>> \n>> -\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params);\n>> +\tvoid process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms);\n>> \tint start();\n>> \tvoid stop();\n>> \n>> @@ -72,9 +72,9 @@ private:\n>> \t\t\t\t std::vector shaderEnv);\n>> \tint linkShaderProgram(void);\n>> \tint getShaderVariableLocations();\n>> -\tvoid setShaderVariableValues(DebayerParams ¶ms);\n>> +\tvoid setShaderVariableValues(const DebayerParams ¶ms);\n>> \tvoid configureTexture(GLuint &texture);\n>> -\tint debayerGPU(MappedFrameBuffer &in, int out_fd, DebayerParams ¶ms);\n>> +\tint debayerGPU(MappedFrameBuffer &in, int out_fd, const DebayerParams ¶ms);\n>> \n>> \t/* Shader program identifiers */\n>> \tGLuint vertexShaderId_ = 0;","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 B2820BDCBF\n\tfor ;\n\tThu, 22 Jan 2026 13:46:49 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id E41AD61FC4;\n\tThu, 22 Jan 2026 14:46:48 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.133.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D3F8661F84\n\tfor ;\n\tThu, 22 Jan 2026 14:46:47 +0100 (CET)","from mail-wm1-f71.google.com (mail-wm1-f71.google.com\n\t[209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-468-s5RHat1OPjqzFgvP7wgvMA-1; 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\n\tThu, 22 Jan 2026 05:46:44 -0800 (PST)","by 2002:a05:600c:34d6:b0:47e:e20e:bbb7 with SMTP id\n\t5b1f17b1804b1-4801eb1080amr316889045e9.25.1769089603605; \n\tThu, 22 Jan 2026 05:46:43 -0800 (PST)"],"From":"Milan Zamazal ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","In-Reply-To":"<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb> (Milan\n\tZamazal's message of \"Thu, 22 Jan 2026 14:36:23 +0100\")","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>\n\t<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","Date":"Thu, 22 Jan 2026 14:46:42 +0100","Message-ID":"<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"6gcijef6Rzpph_QMcc4PI4jfONjBZilwSWycE1qb0cU_1769089604","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable","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":37875,"web_url":"https://patchwork.libcamera.org/comment/37875/","msgid":"<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com>","date":"2026-01-22T13:49:33","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"content":"2026. 01. 22. 14:46 keltezéssel, Milan Zamazal írta:\n> Milan Zamazal writes:\n> \n>> Hi Barnabás,\n>>\n>> thank you for the patch.\n>>\n>> Barnabás Pőcze writes:\n>>\n>>> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n>>> `DebayerParams` object is copied multiple time:\n>>>\n>>> (1) call of `BoundMethodMember<...>::activate()`\n>>> inside `Object::invokeMethod()`\n>>> (2) constructor of `BoundMethodArgs<...>`\n>>> inside `BoundMethodMember<...>::activate()`\n>>> (3) call of `BoundMethodMember<...>::invoke()`\n>>> inside `BoundMethodArgs::invokePack()`\n>>> (4) call of the actual pointer to member function\n>>> inside `BoundMethodMember::invoke()`\n>>>\n>>> Given that the type has a size of 5696 bytes at the moment on x86-64,\n>>> while the size is expected to shrink considerably and compilers might\n>>> avoid one or two of the above copies, this is still not ideal. By making\n>>> `Debayer::process()` take the parameter object by const lvalue reference,\n>>> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n>>\n>> Why RFC? Looks like harmless cleanup.\n>>\n>> Reviewed-by: Milan Zamazal \n>>\n>>> Signed-off-by: Barnabás Pőcze \n>>> ---\n>>> src/libcamera/software_isp/debayer.cpp | 2 +-\n>>> src/libcamera/software_isp/debayer.h | 4 ++--\n>>> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n>>> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n>>> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n>>> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n>>> 6 files changed, 11 insertions(+), 11 deletions(-)\n>>>\n>>> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n>>> index 65a1762dd..3e7702525 100644\n>>> --- a/src/libcamera/software_isp/debayer.cpp\n>>> +++ b/src/libcamera/software_isp/debayer.cpp\n>>> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n>>> * \\brief Select the bayer params to use for the next frame debayer\n>>> * \\param[in] params The parameters to be used in debayering\n>>> */\n>>> -void Debayer::setParams(DebayerParams ¶ms)\n>>> +void Debayer::setParams(const DebayerParams ¶ms)\n>>> {\n>>> \tgreen_ = params.green;\n>>> \tgreenCcm_ = params.greenCcm;\n>>> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n>>> index cd2db9930..99e22ed85 100644\n>>> --- a/src/libcamera/software_isp/debayer.h\n>>> +++ b/src/libcamera/software_isp/debayer.h\n>>> @@ -47,7 +47,7 @@ public:\n>>> \tvirtual std::tuple\n>>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n>>> \n>>> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams params) = 0;\n>>> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n> \n> Well, this looks risky and I think it's better to avoid.\n\nHow so?\n\n\n> \n>>> \tvirtual int start() { return 0; }\n>>> \tvirtual void stop() {}\n>>> \n>>> @@ -92,7 +92,7 @@ private:\n>>> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n>>> \n>>> protected:\n>>> -\tvoid setParams(DebayerParams ¶ms);\n>>> +\tvoid setParams(const DebayerParams ¶ms);\n>>> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n>>> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\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 DA3A0C3220\n\tfor ;\n\tThu, 22 Jan 2026 13:49:37 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 3933961FC4;\n\tThu, 22 Jan 2026 14:49:37 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6B49D61F84\n\tfor ;\n\tThu, 22 Jan 2026 14:49:36 +0100 (CET)","from [192.168.33.25] (185.221.143.114.nat.pool.zt.hu\n\t[185.221.143.114])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id B4D90460;\n\tThu, 22 Jan 2026 14:49:03 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"UsNdZ8fI\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1769089743;\n\tbh=7nayz8E+7x6MLMxkMQAd8v1ieYqdSHsP7nb2caEepsc=;\n\th=Date:Subject:To:Cc:References:From:In-Reply-To:From;\n\tb=UsNdZ8fIhsMrOuXRP+22lSvB6wtiYkGsxYuz2xTIkumA8R7RyHquimsjyzfbGHVb2\n\t5n9QoZb6Z3DY1sRjqlm3SmD1+NVLoLERWZaLJ7A8jjIE9OE9W/4B06DofgRTRSJrkm\n\tEGfyVGWhyT6JSAruvbuAWWvMaucM5XCqNz/KQ9/E=","Message-ID":"<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com>","Date":"Thu, 22 Jan 2026 14:49:33 +0100","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","To":"Milan Zamazal ","Cc":"libcamera-devel@lists.libcamera.org","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>\n\t<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Content-Language":"en-US, hu-HU","In-Reply-To":"<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","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":37879,"web_url":"https://patchwork.libcamera.org/comment/37879/","msgid":"<85pl71vg3n.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-01-22T15:09:48","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Barnabás Pőcze writes:\n\n> 2026. 01. 22. 14:46 keltezéssel, Milan Zamazal írta:\n>> Milan Zamazal writes:\n>> \n>\n>>> Hi Barnabás,\n>>>\n>>> thank you for the patch.\n>>>\n>>> Barnabás Pőcze writes:\n>>>\n>>>> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n>>>> `DebayerParams` object is copied multiple time:\n>>>>\n>>>> (1) call of `BoundMethodMember<...>::activate()`\n>>>> inside `Object::invokeMethod()`\n>>>> (2) constructor of `BoundMethodArgs<...>`\n>>>> inside `BoundMethodMember<...>::activate()`\n>>>> (3) call of `BoundMethodMember<...>::invoke()`\n>>>> inside `BoundMethodArgs::invokePack()`\n>>>> (4) call of the actual pointer to member function\n>>>> inside `BoundMethodMember::invoke()`\n>>>>\n>>>> Given that the type has a size of 5696 bytes at the moment on x86-64,\n>>>> while the size is expected to shrink considerably and compilers might\n>>>> avoid one or two of the above copies, this is still not ideal. By making\n>>>> `Debayer::process()` take the parameter object by const lvalue reference,\n>>>> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n>>>\n>>> Why RFC? Looks like harmless cleanup.\n>>>\n>>> Reviewed-by: Milan Zamazal \n>>>\n>>>> Signed-off-by: Barnabás Pőcze \n>>>> ---\n>>>> src/libcamera/software_isp/debayer.cpp | 2 +-\n>>>> src/libcamera/software_isp/debayer.h | 4 ++--\n>>>> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n>>>> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n>>>> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n>>>> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n>>>> 6 files changed, 11 insertions(+), 11 deletions(-)\n>>>>\n>>>> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n>>>> index 65a1762dd..3e7702525 100644\n>>>> --- a/src/libcamera/software_isp/debayer.cpp\n>>>> +++ b/src/libcamera/software_isp/debayer.cpp\n>>>> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n>>>> * \\brief Select the bayer params to use for the next frame debayer\n>>>> * \\param[in] params The parameters to be used in debayering\n>>>> */\n>>>> -void Debayer::setParams(DebayerParams ¶ms)\n>>>> +void Debayer::setParams(const DebayerParams ¶ms)\n>>>> {\n>>>> \tgreen_ = params.green;\n>>>> \tgreenCcm_ = params.greenCcm;\n>>>> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n>>>> index cd2db9930..99e22ed85 100644\n>>>> --- a/src/libcamera/software_isp/debayer.h\n>>>> +++ b/src/libcamera/software_isp/debayer.h\n>>>> @@ -47,7 +47,7 @@ public:\n>>>> \tvirtual std::tuple\n>>>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n>>>> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams\n>>>> params) = 0;\n>>>> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n>> Well, this looks risky and I think it's better to avoid.\n>\n> How so?\n\nIf debayering and algorithms run asynchronously and we don't have clear\nguarantees that params don't change while debayering can still consume\nthem, we can get a subtle bug. Saving the copying wouldn't be worth the\nrisk.\n\n>> \n>>>> \tvirtual int start() { return 0; }\n>>>> \tvirtual void stop() {}\n>>>> @@ -92,7 +92,7 @@ private:\n>>>> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n>>>> protected:\n>>>> -\tvoid setParams(DebayerParams ¶ms);\n>>>> +\tvoid setParams(const DebayerParams ¶ms);\n>>>> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n>>>> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\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 48F5DBDCBF\n\tfor ;\n\tThu, 22 Jan 2026 15:09:57 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 63DEF61FC9;\n\tThu, 22 Jan 2026 16:09:56 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.133.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 150B961F84\n\tfor ;\n\tThu, 22 Jan 2026 16:09:54 +0100 (CET)","from mail-wm1-f71.google.com (mail-wm1-f71.google.com\n\t[209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-376-XNAFxKggN_m3iNYVZB7Ozw-1; Thu, 22 Jan 2026 10:09:51 -0500","by mail-wm1-f71.google.com with SMTP id\n\t5b1f17b1804b1-47d3c9b8c56so19446445e9.0\n\tfor ;\n\tThu, 22 Jan 2026 07:09:51 -0800 (PST)","from mzamazal-thinkpadp1gen7.tpbc.csb\n\t(ip-77-48-47-2.net.vodafone.cz. 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\n\tThu, 22 Jan 2026 07:09:49 -0800 (PST)","by 2002:a05:600c:37c8:b0:477:af07:dd21 with SMTP id\n\t5b1f17b1804b1-4801eb0d71cmr288184125e9.25.1769094589422; \n\tThu, 22 Jan 2026 07:09:49 -0800 (PST)"],"From":"Milan Zamazal ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","In-Reply-To":"<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com> (\n\t=?utf-8?b?IkJhcm5hYsOhcyBQxZFjemUiJ3M=?= message of \"Thu,\n\t22 Jan 2026 14:49:33 +0100\")","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>\n\t<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com>","Date":"Thu, 22 Jan 2026 16:09:48 +0100","Message-ID":"<85pl71vg3n.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"EzuD5WY1D6BLbsvQmRGmuzUPGfTcOFrWK-bxB4ZT3PE_1769094591","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable","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":37880,"web_url":"https://patchwork.libcamera.org/comment/37880/","msgid":"<8bd7148d-df10-4bbe-95a1-adc80b842e18@ideasonboard.com>","date":"2026-01-22T15:18:35","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"content":"2026. 01. 22. 16:09 keltezéssel, Milan Zamazal írta:\n> Barnabás Pőcze writes:\n> \n>> 2026. 01. 22. 14:46 keltezéssel, Milan Zamazal írta:\n>>> Milan Zamazal writes:\n>>>\n>>\n>>>> Hi Barnabás,\n>>>>\n>>>> thank you for the patch.\n>>>>\n>>>> Barnabás Pőcze writes:\n>>>>\n>>>>> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n>>>>> `DebayerParams` object is copied multiple time:\n>>>>>\n>>>>> (1) call of `BoundMethodMember<...>::activate()`\n>>>>> inside `Object::invokeMethod()`\n>>>>> (2) constructor of `BoundMethodArgs<...>`\n>>>>> inside `BoundMethodMember<...>::activate()`\n>>>>> (3) call of `BoundMethodMember<...>::invoke()`\n>>>>> inside `BoundMethodArgs::invokePack()`\n>>>>> (4) call of the actual pointer to member function\n>>>>> inside `BoundMethodMember::invoke()`\n>>>>>\n>>>>> Given that the type has a size of 5696 bytes at the moment on x86-64,\n>>>>> while the size is expected to shrink considerably and compilers might\n>>>>> avoid one or two of the above copies, this is still not ideal. By making\n>>>>> `Debayer::process()` take the parameter object by const lvalue reference,\n>>>>> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n>>>>\n>>>> Why RFC? Looks like harmless cleanup.\n>>>>\n>>>> Reviewed-by: Milan Zamazal \n>>>>\n>>>>> Signed-off-by: Barnabás Pőcze \n>>>>> ---\n>>>>> src/libcamera/software_isp/debayer.cpp | 2 +-\n>>>>> src/libcamera/software_isp/debayer.h | 4 ++--\n>>>>> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n>>>>> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n>>>>> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n>>>>> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n>>>>> 6 files changed, 11 insertions(+), 11 deletions(-)\n>>>>>\n>>>>> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n>>>>> index 65a1762dd..3e7702525 100644\n>>>>> --- a/src/libcamera/software_isp/debayer.cpp\n>>>>> +++ b/src/libcamera/software_isp/debayer.cpp\n>>>>> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n>>>>> * \\brief Select the bayer params to use for the next frame debayer\n>>>>> * \\param[in] params The parameters to be used in debayering\n>>>>> */\n>>>>> -void Debayer::setParams(DebayerParams ¶ms)\n>>>>> +void Debayer::setParams(const DebayerParams ¶ms)\n>>>>> {\n>>>>> \tgreen_ = params.green;\n>>>>> \tgreenCcm_ = params.greenCcm;\n>>>>> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n>>>>> index cd2db9930..99e22ed85 100644\n>>>>> --- a/src/libcamera/software_isp/debayer.h\n>>>>> +++ b/src/libcamera/software_isp/debayer.h\n>>>>> @@ -47,7 +47,7 @@ public:\n>>>>> \tvirtual std::tuple\n>>>>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n>>>>> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams\n>>>>> params) = 0;\n>>>>> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n>>> Well, this looks risky and I think it's better to avoid.\n>>\n>> How so?\n> \n> If debayering and algorithms run asynchronously and we don't have clear\n> guarantees that params don't change while debayering can still consume\n> them, we can get a subtle bug. Saving the copying wouldn't be worth the\n> risk.\n\nOne copy still remains.\n\nvoid SoftwareIsp::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output)\n{\n\tipa_->computeParams(frame);\n\tdebayer_->invokeMethod(&Debayer::process,\n\t\t\t ConnectionTypeQueued, frame, input, output, debayerParams_);\n}\n\nhere `Object::invokeMethod()` will make a copy of the `DebayerParams` object:\n\n * Arguments \\a args passed by value or reference are copied, while pointers\n * are passed untouched. The caller shall ensure that any pointer argument\n * remains valid until the method is invoked.\n\nso I am fairly certain this should cause no issues. It mostly gets\nrid of the copies that happen inside the cross-thread calling mechanism.\nBut there will still be one copy inside `invokeMethod()`.\n\n\n> \n>>>\n>>>>> \tvirtual int start() { return 0; }\n>>>>> \tvirtual void stop() {}\n>>>>> @@ -92,7 +92,7 @@ private:\n>>>>> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n>>>>> protected:\n>>>>> -\tvoid setParams(DebayerParams ¶ms);\n>>>>> +\tvoid setParams(const DebayerParams ¶ms);\n>>>>> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n>>>>> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\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 901A0C3220\n\tfor ;\n\tThu, 22 Jan 2026 15:18:41 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id AA0AD61FC4;\n\tThu, 22 Jan 2026 16:18:40 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0937561F84\n\tfor ;\n\tThu, 22 Jan 2026 16:18:40 +0100 (CET)","from [192.168.33.25] (185.221.143.114.nat.pool.zt.hu\n\t[185.221.143.114])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id B421F460;\n\tThu, 22 Jan 2026 16:18:06 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"rqyjcNuG\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1769095087;\n\tbh=/NY2jc7lTury638QlvSfKKYvOSeV4a/e2EL1uGVH4Rw=;\n\th=Date:Subject:To:Cc:References:From:In-Reply-To:From;\n\tb=rqyjcNuGKe5MQ825Zgqlj4rZ2MXoi32AjIiM0CozIHx5MsCcoZrFY8MIx/gFiaz+8\n\t5Sz4uWLjbA5QAx0tQsfpM1Lw4m9vMNvbtcL/8elahHRdYYKWt6o9YWsKiO2eiIzZUw\n\th6te8N26RXnGPEUKSxpv1zEj66uFgZxMpyU742cE=","Message-ID":"<8bd7148d-df10-4bbe-95a1-adc80b842e18@ideasonboard.com>","Date":"Thu, 22 Jan 2026 16:18:35 +0100","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","To":"Milan Zamazal ","Cc":"libcamera-devel@lists.libcamera.org","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>\n\t<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com>\n\t<85pl71vg3n.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Content-Language":"en-US, hu-HU","In-Reply-To":"<85pl71vg3n.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","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":37881,"web_url":"https://patchwork.libcamera.org/comment/37881/","msgid":"<85ldhpvfa4.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-01-22T15:27:31","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Barnabás Pőcze writes:\n\n> 2026. 01. 22. 16:09 keltezéssel, Milan Zamazal írta:\n>> Barnabás Pőcze writes:\n>> \n>\n>>> 2026. 01. 22. 14:46 keltezéssel, Milan Zamazal írta:\n>>>> Milan Zamazal writes:\n>>>>\n>>>\n>>>>> Hi Barnabás,\n>>>>>\n>>>>> thank you for the patch.\n>>>>>\n>>>>> Barnabás Pőcze writes:\n>>>>>\n>>>>>> When calling `Debayer::process()` from `SoftwareIsp::process()`, the\n>>>>>> `DebayerParams` object is copied multiple time:\n>>>>>>\n>>>>>> (1) call of `BoundMethodMember<...>::activate()`\n>>>>>> inside `Object::invokeMethod()`\n>>>>>> (2) constructor of `BoundMethodArgs<...>`\n>>>>>> inside `BoundMethodMember<...>::activate()`\n>>>>>> (3) call of `BoundMethodMember<...>::invoke()`\n>>>>>> inside `BoundMethodArgs::invokePack()`\n>>>>>> (4) call of the actual pointer to member function\n>>>>>> inside `BoundMethodMember::invoke()`\n>>>>>>\n>>>>>> Given that the type has a size of 5696 bytes at the moment on x86-64,\n>>>>>> while the size is expected to shrink considerably and compilers might\n>>>>>> avoid one or two of the above copies, this is still not ideal. By making\n>>>>>> `Debayer::process()` take the parameter object by const lvalue reference,\n>>>>>> only the copy in the `BoundMethodArgs` constructor remains. So do that.\n>>>>>\n>>>>> Why RFC? Looks like harmless cleanup.\n>>>>>\n>>>>> Reviewed-by: Milan Zamazal \n>>>>>\n>>>>>> Signed-off-by: Barnabás Pőcze \n>>>>>> ---\n>>>>>> src/libcamera/software_isp/debayer.cpp | 2 +-\n>>>>>> src/libcamera/software_isp/debayer.h | 4 ++--\n>>>>>> src/libcamera/software_isp/debayer_cpu.cpp | 2 +-\n>>>>>> src/libcamera/software_isp/debayer_cpu.h | 2 +-\n>>>>>> src/libcamera/software_isp/debayer_egl.cpp | 6 +++---\n>>>>>> src/libcamera/software_isp/debayer_egl.h | 6 +++---\n>>>>>> 6 files changed, 11 insertions(+), 11 deletions(-)\n>>>>>>\n>>>>>> diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp\n>>>>>> index 65a1762dd..3e7702525 100644\n>>>>>> --- a/src/libcamera/software_isp/debayer.cpp\n>>>>>> +++ b/src/libcamera/software_isp/debayer.cpp\n>>>>>> @@ -401,7 +401,7 @@ Debayer::~Debayer()\n>>>>>> * \\brief Select the bayer params to use for the next frame debayer\n>>>>>> * \\param[in] params The parameters to be used in debayering\n>>>>>> */\n>>>>>> -void Debayer::setParams(DebayerParams ¶ms)\n>>>>>> +void Debayer::setParams(const DebayerParams ¶ms)\n>>>>>> {\n>>>>>> \tgreen_ = params.green;\n>>>>>> \tgreenCcm_ = params.greenCcm;\n>>>>>> diff --git a/src/libcamera/software_isp/debayer.h b/src/libcamera/software_isp/debayer.h\n>>>>>> index cd2db9930..99e22ed85 100644\n>>>>>> --- a/src/libcamera/software_isp/debayer.h\n>>>>>> +++ b/src/libcamera/software_isp/debayer.h\n>>>>>> @@ -47,7 +47,7 @@ public:\n>>>>>> \tvirtual std::tuple\n>>>>>> \tstrideAndFrameSize(const PixelFormat &outputFormat, const Size &size) = 0;\n>>>>>> -\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, DebayerParams\n>>>>>> params) = 0;\n>>>>>> +\tvirtual void process(uint32_t frame, FrameBuffer *input, FrameBuffer *output, const DebayerParams ¶ms) = 0;\n>>>> Well, this looks risky and I think it's better to avoid.\n>>>\n>>> How so?\n>> If debayering and algorithms run asynchronously and we don't have clear\n>> guarantees that params don't change while debayering can still consume\n>> them, we can get a subtle bug. Saving the copying wouldn't be worth the\n>> risk.\n>\n> One copy still remains.\n>\n> void SoftwareIsp::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output)\n> {\n> \tipa_->computeParams(frame);\n> \tdebayer_->invokeMethod(&Debayer::process,\n> \t\t\t ConnectionTypeQueued, frame, input, output, debayerParams_);\n> }\n>\n> here `Object::invokeMethod()` will make a copy of the `DebayerParams` object:\n>\n> * Arguments \\a args passed by value or reference are copied, while pointers\n> * are passed untouched. The caller shall ensure that any pointer argument\n> * remains valid until the method is invoked.\n>\n> so I am fairly certain this should cause no issues. It mostly gets\n> rid of the copies that happen inside the cross-thread calling mechanism.\n> But there will still be one copy inside `invokeMethod()`.\n\nAh, right, thank you for clarification. Sorry for the noise and not\nreading the commit message carefully enough.\n\n>> \n>>>>\n>>>>>> \tvirtual int start() { return 0; }\n>>>>>> \tvirtual void stop() {}\n>>>>>> @@ -92,7 +92,7 @@ private:\n>>>>>> \tvirtual Size patternSize(PixelFormat inputFormat) = 0;\n>>>>>> protected:\n>>>>>> -\tvoid setParams(DebayerParams ¶ms);\n>>>>>> +\tvoid setParams(const DebayerParams ¶ms);\n>>>>>> \tvoid dmaSyncBegin(std::vector &dmaSyncers, FrameBuffer *input, FrameBuffer *output);\n>>>>>> \tstatic bool isStandardBayerOrder(BayerFormat::Order order);\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 AA9ACBDCBF\n\tfor ;\n\tThu, 22 Jan 2026 15:27:40 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id EDD6561F84;\n\tThu, 22 Jan 2026 16:27:39 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E101F61F84\n\tfor ;\n\tThu, 22 Jan 2026 16:27:37 +0100 (CET)","from mail-wm1-f69.google.com (mail-wm1-f69.google.com\n\t[209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-373-MCATC1OKO2eQEkan2dVzuw-1; Thu, 22 Jan 2026 10:27:35 -0500","by mail-wm1-f69.google.com with SMTP id\n\t5b1f17b1804b1-47edee0b11cso6459645e9.1\n\tfor ;\n\tThu, 22 Jan 2026 07:27:35 -0800 (PST)","from mzamazal-thinkpadp1gen7.tpbc.csb\n\t(ip-77-48-47-2.net.vodafone.cz. 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\n\tThu, 22 Jan 2026 07:27:33 -0800 (PST)","by 2002:a05:600c:c16b:b0:47e:e78a:c831 with SMTP id\n\t5b1f17b1804b1-4801eb14ff0mr294649885e9.36.1769095653243; \n\tThu, 22 Jan 2026 07:27:33 -0800 (PST)"],"From":"Milan Zamazal ","To":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Cc":"libcamera-devel@lists.libcamera.org","Subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","In-Reply-To":"<8bd7148d-df10-4bbe-95a1-adc80b842e18@ideasonboard.com> (\n\t=?utf-8?b?IkJhcm5hYsOhcyBQxZFjemUiJ3M=?= message of \"Thu,\n\t22 Jan 2026 16:18:35 +0100\")","References":"<20260120170701.400944-1-barnabas.pocze@ideasonboard.com>\n\t<857bt9wyzs.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<85343xwyil.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<2c06803e-1a0c-43d8-bddc-65eecc42e533@ideasonboard.com>\n\t<85pl71vg3n.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>\n\t<8bd7148d-df10-4bbe-95a1-adc80b842e18@ideasonboard.com>","Date":"Thu, 22 Jan 2026 16:27:31 +0100","Message-ID":"<85ldhpvfa4.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","User-Agent":"Gnus/5.13 (Gnus v5.13)","MIME-Version":"1.0","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"2rBk0BdIs_uw_prxSdpYzfHYUlLnhOYSK_HOwl-6L8M_1769095654","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=utf-8","Content-Transfer-Encoding":"quoted-printable","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":37882,"web_url":"https://patchwork.libcamera.org/comment/37882/","msgid":"<2e9f5167-79f4-40bf-a5a8-7ce77ef4a23d@linaro.org>","date":"2026-01-22T15:54:45","subject":"Re: [RFC PATCH v1] libcamera: software_isp: debayer: Take\n\t`DebayerParams` by ref","submitter":{"id":175,"url":"https://patchwork.libcamera.org/api/people/175/","name":"Bryan O'Donoghue","email":"bryan.odonoghue@linaro.org"},"content":"On 22/01/2026 15:18, Barnabás Pőcze wrote:\n> One copy still remains.\n> \n> void SoftwareIsp::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output)\n> {\n> \tipa_->computeParams(frame);\n> \tdebayer_->invokeMethod(&Debayer::process,\n> \t\t\t ConnectionTypeQueued, frame, input, output, debayerParams_);\n> }\n\nWe should really have code we know to be thread-safe - or not - whatever \nthe case may be.\n\nA copy is a low-intervention version of thread synchronisation though.\n\nAssuming you've tested this with gpuisp.\n\nReviewed-by: Bryan O'Donoghue \n\n---\nbod","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 3E889C3220\n\tfor ;\n\tThu, 22 Jan 2026 15:54:52 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 698AF61FC4;\n\tThu, 22 Jan 2026 16:54:51 +0100 (CET)","from mail-wm1-x332.google.com (mail-wm1-x332.google.com\n\t[IPv6:2a00:1450:4864:20::332])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6CD8661F84\n\tfor ;\n\tThu, 22 Jan 2026 16:54:50 +0100 (CET)","by mail-wm1-x332.google.com with SMTP id\n\t5b1f17b1804b1-47edd6111b4so12778155e9.1\n\tfor ;\n\tThu, 22 Jan 2026 07:54:50 -0800 (PST)","from [192.168.0.40] (188-141-3-146.dynamic.upc.ie. 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