From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794274954; b=cjUR82y87w0cCdT7g3szKMGgA4jVx/etAMEf7Cu8OAYSdzKxNhtNTDtEe9e9m2FPK1LV ATwN4D6IhLi7yPqY3zqjCbx154Duf/zCp6gxw4JW4gvsfuF7OitA4rXUhCoc7aQli3CxQ XoKraMed/XCnV9AW9UwRGQYvAGJbuYgOrkjEzOwMnH6oRGWshj397ExPg+qf1pvGqxj5Z cJ1sm/f4DTkh6dUizYWhQvuy50xuww4u5aAdfojyx71ECtf0qJWZBzpj/Ab3VR3vzPhQe NUFfD3cs2LAJLU1KlQQc9QsG4GC0Ky1dIO5MDXzb+GAybXZAn0PAD7Ka6E7tIwih7MA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794274954; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=GS5QcbHcgeHbE8fi9wdjI8BAF+Ucegl1CTEttneWlv0=; b=cgGRCoqfOksM2pDgMGv7VJ8woj2uN2VbwrjB0CD4laViwnV+mRATyfQctZkAf4owIaAW Iq+8lUEHLjG6yy2baVVCs33yg3QWwh/9R1cHeFfF6fFOnqaXd2juSdBa2ehkw4sWNb6BY DmmWd2Ducj3CmtJqalmPgj38Ii9vq9/D+Cae8ADPqCbPvl8exc9Y7EaSD4jTRKXe+ysti +mV6cYgFiYGiDbo/JvrOpnerM/jZc2jwJbUKiBbSsbzXU+32liPOKPcR6NvWG0hHFf7lA Qgh56Wp4axkpauywCZujmY/PNuAsiqoGn3KY3kRVwzrrsg8Q9BYLETDifP2L8d0TExg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LEk+bKCO; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A3E3606A933 for ; Tue, 10 Nov 2026 01:42:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LEk+bKCO Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BAA81F0089F; Tue, 10 Nov 2026 01:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794274954; bh=GS5QcbHcgeHbE8fi9wdjI8BAF+Ucegl1CTEttneWlv0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=LEk+bKCOHQ2N428/Ggc2q+LzNZTu5eHHesSNO5F9fAGNcPMKZV3UCTyZMBnaFxrFu AzNGI9Ooxcig8omB4TLeL/Dp2Uw8YOukbdNYAOmXdKD9SVz57E2SPMN59wIMdHtkjC /Gzzp3kg1616NInQnsn+XLpO9eBibUBim8GaXN8zqjEMBnpTYUYLtCggv10/3/jVGE KEOHXuU1xZCJKhh+puAq0jmJWxu9VynkwfEl4U6xl3pktooEf32vlTx2gx+bGS0wex vusJAK8mwMQUuJdmOeuUWlRjBbsUp8+sboWamDtJ6i7iOyj1Uz3UdJLurq7xU/GlkM hURg3M9KkJ9xA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 05/10] riscv: stacktrace: disable KASAN and KCOV instrumentation for stacktrace.o Reply-To: sashiko-reviews@lists.linux.dev To: "Shuai Xue" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261110013750.36800-6-xueshuai@linux.alibaba.com> References: <20260914092648.51254-1-xueshuai@linux.alibaba.com> <20261110013750.36800-1-xueshuai@linux.alibaba.com> <20261110013750.36800-6-xueshuai@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 01:42:34 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Wang Han >=20 > KASAN records stack traces for every alloc/free, which means it walks > the unwinder very frequently. Instrumenting the stack trace collection > code itself adds substantial overhead and makes the traces themselves > noisier. >=20 > KCOV instruments every basic-block edge. The unwinder is a hot path, > especially with KASAN enabled, so KCOV instrumentation has the same kind > of cost and noise problem here. >=20 > Mark stacktrace.o as not KASAN- or KCOV-instrumented, matching the x86 > treatment of its stack unwinding code. RISC-V keeps the relevant unwinder > code in stacktrace.o, so a single translation-unit annotation covers the > equivalent scope. This is a prerequisite preference for the upcoming > reliable unwinder, but the change is valid on its own. >=20 > Reviewed-by: Shuai Xue > Reviewed-by: Martin Kaiser > Tested-by: Martin Kaiser > Signed-off-by: Wang Han > Signed-off-by: Shuai Xue Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110013750.3680= 0-1-xueshuai@linux.alibaba.com?part=3D5