From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27BABD43361 for ; Fri, 12 Dec 2025 01:12:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:To:From:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5hWXJxhX5wME82FGFIrBRzJRgBsQr+OdqP9sUt7Njis=; b=2+gYvHH0jntZNRHZWqBz56vBU0 gzusGHsn/r9hSOCZay6mqoLJO/+hkQoeV6odQEwT06OS75XrLuJIkiv8zZhbT2FuOgpzkD0OELU51 u3osPqX0jo28+kLUDdjEU1GC7AgUyifxe3/85THwBa90sHrO2ZeZU51ylxoDRPRQ+dxM3QRSjSBg1 3lCyiJwVhbj23BqiGkYX57mnbcL8mSrSrbeVhift6+39igGQk8sEYWXNr+nmb+iuG+8kGPNREX7j6 bnffvTrIZQrIrTDB2SYjZoqr9YTVfZ2Yv105HDzbZOLlSjX9Ybqt6OHFxt5HIyRrUiayoHcaVfnG3 ngm0gYhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vTrhm-0000000HTcb-3Vc8; Fri, 12 Dec 2025 01:12:22 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vTrhj-0000000HTcC-28lT for linux-arm-kernel@lists.infradead.org; Fri, 12 Dec 2025 01:12:20 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1765501936; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5hWXJxhX5wME82FGFIrBRzJRgBsQr+OdqP9sUt7Njis=; b=VI3pH1VcrifbeS9kA3FPBSHylFeLOXjGAye2KPD1jpu3JUjgxWpVrJ7FpQfVodUHXTPATC PQlw6QNdJC8x3jc3F7/cvot67LJEbPwOVjjCuGOKF06aYRXBEKuXVBjTQO3rNVN8b2hBhQ Yl3yor8zKz7LVv5/SB23naFPfsbs5EwQ7Sn0p2S7wqJ1UN1eZTVTiZ2WWwZW//z9vYv3rD OhKN3zFynVYPnDa1v3JPtxSB+ZVXKoeQCfCyW7TiojfhNwEq77I79urwK+TPPzwrc5K/mN UpjuzcfUNuBZI3bD4d7Ah5IJ51GjTwUwJC5bk3pkqA4qB+e4NbGbrSFULQvOTw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1765501936; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5hWXJxhX5wME82FGFIrBRzJRgBsQr+OdqP9sUt7Njis=; b=wX3HdKaaXflaOMKhWkolNsCkdzaVm6/IgPyOJ8qgM/d5MMYeT9V0ed4WOBgPjrqHHa52MA 7L1NceDmnev/reDQ== To: Kevin Brodsky , 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 Subject: Re: [PATCH v9 15/16] entry: Inline syscall_exit_work() In-Reply-To: References: <20251204082123.2792067-1-ruanjinjie@huawei.com> <20251204082123.2792067-16-ruanjinjie@huawei.com> <87345hfqyh.ffs@tglx> Date: Fri, 12 Dec 2025 10:12:13 +0900 Message-ID: <87wm2sec5u.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251211_171219_710980_32226644 X-CRM114-Status: GOOD ( 10.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Dec 11 2025 at 10:52, Kevin Brodsky wrote: > 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. Indeed. Confused myself.