From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4B4AA21423C; Thu, 11 Dec 2025 09:52:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765446747; cv=none; b=aky2UxSaEAHfqFN7S9X9SZnxnj1o1mKiactaAEI7U+oEg/bdhke4sacqzzpo49r9fwLUkNHF/RncXBGL3x3wOt/EtGB5D3Q3m8UTLQf0ajtUNuelFs7n9YKZONJlbGx+W9SWbAn+9yYqMiG7PGE0CBGhp6LRmblrWyaAT5qbXo4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765446747; c=relaxed/simple; bh=ShyQdUrLPBAZ0jmMVP8BT9u1QAUAVpOqsZkPi86HuaY=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=B8o7q6jSuWuRFhw3+FcVla3FvVgt4cSQIq6SH1XD2srvveO4GkNFzc7U6Gk9NWsW0fwDjsqbee/9bSYC65zudPqONWv/JdMXvA1KfMXqX21jDrdn+rFNRKWPQCbgDYGbqXSu5iOrAFKqwqr7dpCq6/w23QHX3K3XV9IWQloETuA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 49E78153B; Thu, 11 Dec 2025 01:52:17 -0800 (PST) Received: from [10.57.46.84] (unknown [10.57.46.84]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EA7A33F73B; Thu, 11 Dec 2025 01:52:17 -0800 (PST) Message-ID: Date: Thu, 11 Dec 2025 10:52:11 +0100 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 15/16] entry: Inline syscall_exit_work() To: Thomas Gleixner , Jinjie Ruan , catalin.marinas@arm.com, will@kernel.org, oleg@redhat.com, peterz@infradead.org, luto@kernel.org, shuah@kernel.org, kees@kernel.org, wad@chromium.org, deller@gmx.de, macro@orcam.me.uk, charlie@rivosinc.com, ldv@strace.io, mark.rutland@arm.com, song@kernel.org, ryan.roberts@arm.com, ada.coupriediaz@arm.com, anshuman.khandual@arm.com, broonie@kernel.org, pengcan@kylinos.cn, dvyukov@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20251204082123.2792067-1-ruanjinjie@huawei.com> <20251204082123.2792067-16-ruanjinjie@huawei.com> <87345hfqyh.ffs@tglx> From: Kevin Brodsky Content-Language: en-GB In-Reply-To: <87345hfqyh.ffs@tglx> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/12/2025 07:55, Thomas Gleixner wrote: > I have a suspicion that it is TIF_NOTIFY_RESUME. If that's the case > you're seing the RSEQ overhead, which should be completely gone with the > rewrite that got just merged into Linus tree. I don't think this is related. This patch inlines syscall_exit_work(), which is called if some flag in SYSCALL_WORK_EXIT is set. This includes syscall-specific stuff like tracing and singlestep. TIF_NOTIFY_RESUME is part of EXIT_TO_USER_MODE_WORK, handled in exit_to_user_mode_prepare(), and isn't specific to syscall handling. - Kevin