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 6BC0DFF886C for ; Tue, 28 Apr 2026 08:51:39 +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:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=50Hh7cUTPx7OLiiHb2Cd7Al1d1Mbhergb/FOrrMc6dc=; b=bSCMR7x4ftqQ6av5LfXXTO/PQ4 HQe5Rx3n/g5WrOB0KHgsDHrGtjuI5O8rSMD0XVkoav4v113e+iDqZEKyPHLS6yiqVpO2kg7MWUWxL 6SE4TntbN8aps3/yW5Aisg77gpPFhE4jEOuK2R9HRmIu7tJjXAQpsfDLmEizKXtLAbYoHOZbTUYtJ VFuDycASGHF/5UoBi5ilbcw6E2T8k4/NwQoU+EwkOscO1N82mZURS5Qfpwpz4KnhKmIDsnfbAT2pW ezvYGb3OCfLfqiXGen3YiunppcuyX/gBsyM6XI3a22OT++oF147p6L+6HkOWDYsZbFu9hDpUfB09U 3uE6kLlw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHeAJ-00000000v2o-2HbW; Tue, 28 Apr 2026 08:51:35 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHeAI-00000000v2a-0h0j for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2026 08:51:34 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 849A960141; Tue, 28 Apr 2026 08:51:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AF33C2BCAF; Tue, 28 Apr 2026 08:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777366293; bh=i+gw1fUS40ohLdc9hars3DbakHqzU1swpdINODPO6os=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=eXmN98cVMNrCbnHMFjHbGS84RGWKEra7LXonBvzfuwfGmIXZisbJcekgqvKFDgY7L PuUUw/a9cU4yFuq3aiogZuzehQ6GhvTRcFM1+3BateDmaE/2WnyKHzIqzU6f3a11bM cD6k/HarW9MZRR7lSuQtaLOuTMq5NXOwO9m0zI1L6UQFvhJrIYEBCMU5TpXYSjfLaP JuU4TZFger38FLg2yc+xVZTKSd7w5GDTpHloQL4Cw32Lni6JRZLELf98vzQ2XblLEv i1MI8atlgEEo6NOjevfuR77HjT2qhgXnHS82eqxwlvAMae3CoZWlPxWjHGszWEvvtT ibFsXcT1i3h/w== From: Thomas Gleixner To: Peter Zijlstra Cc: Mathias Stearn , Dmitry Vyukov , Jinjie Ruan , linux-man@vger.kernel.org, Mark Rutland , Mathieu Desnoyers , Catalin Marinas , Will Deacon , Boqun Feng , "Paul E. McKenney" , Chris Kennelly , regressions@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ingo Molnar , Blake Oler , Florian Weimer , Rich Felker , Matthew Wilcox , Greg Kroah-Hartman , Linus Torvalds Subject: Re: [REGRESSION] rseq: refactoring in v6.19 broke everyone on arm64 and tcmalloc everywhere In-Reply-To: <20260428073938.GH3126523@noisy.programming.kicks-ass.net> References: <87ik9i0xlj.ffs@tglx> <87a4ut1njh.ffs@tglx> <87v7dgzbo7.ffs@tglx> <20260424150318.GE641209@noisy.programming.kicks-ass.net> <87se8kywhb.ffs@tglx> <87jyttz8cf.ffs@tglx> <20260428073938.GH3126523@noisy.programming.kicks-ass.net> Date: Tue, 28 Apr 2026 10:51:29 +0200 Message-ID: <87zf2nxyb2.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain 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 Tue, Apr 28 2026 at 09:39, Peter Zijlstra wrote: > On Mon, Apr 27, 2026 at 12:04:48AM +0200, Thomas Gleixner wrote: >> static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) >> { >> - if (IS_ENABLED(CONFIG_GENERIC_IRQ_ENTRY)) { >> + if (IS_ENABLED(CONFIG_GENERIC_IRQ_ENTRY) && rseq_optimized(current)) { > > rseq_optimized() already implies GENERIC_IRQ_ENTRY Indeed. >> + u8 optimized; >> union { >> u16 error; >> struct { > > I know you like the 'optimized' name, it is faster etc. However, the > description there suggests: has_rseq_v2 not be a bad name. > > And while I write this, I figured we could have the value of has_rseq be > 2, rather than 1, but this might end up generating worse code, dunno, > haven't tried yet. Tried that early on and it was worse, but back the approach has changed since then and I just validated that it's actually fine to do so. Fixed. Thanks, tglx