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 3A5EAC624A4 for ; Thu, 3 Sep 2026 16:47:50 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=PE4M5bZ8qa5ONlWyjoO6PT9YT/rm032gR13k1+hQA+s=; b=tzHkS3IQnMJmxjFcbzrh8KEz2b gzDmoqQ61FUg40Jy75rXT56pdwWS+1yaZHTiiw8vnK2FrS4xld15HeugNQqrkqdE39ahUFvoFQy5B IQmRcHzylfCH8mhYOe9+GbuX2QPvYfsS3w/sqcaW0dw/ooeN15zfzLY/fnv5SE3YT2clnKr1kJxrQ WIv63w59gCaTCsiWZ02/FRGYN+STgLmPW2ycKSC/ZNElTWB2pnKmAn3qRPFgoLLJBmFq3JraVRAVS BOl69/aNwTgezRpMdasi0bupHO8hzrog4SrRVE6wTVlOynwQ9c14qneiG0eY6olSIEC0NkSt8LTRZ jSi6ALwg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2AbF-00000000D21-1t7W; Thu, 03 Sep 2026 16:47:41 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2AbC-00000000D1K-0OfR for linux-arm-kernel@lists.infradead.org; Thu, 03 Sep 2026 16:47:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=PE4M5bZ8qa5ONlWyjoO6PT9YT/rm032gR13k1+hQA+s=; b=I23Lcsn3E+BTZqmu+d5CGfgHwK 3qS6wiCrS19b//RLzh7QxvWrqznkylmRe1kmkX2xuzrC1DhZrPi+XVYTpkPfwh+4CAAfHo+/iPG1g X3wTaXN/QJ6sKW7EmH9x50yocWgsxMCxGEXX1+TQUR6JZZcSX6wGKgBaQFVQc3ZGNMOkOlRVU4bbC oef/ChSoq+1JtplljCZYXw/S8hk1QUnR9AHu8CzVdiMaLPu61MKtQgZt+4faKdoy0dO91k0lnwfrx eOOA+mxx+nnaHy7Lhg0GuOeZN9zcCmj+X+fZ09c3I5MPrQfLBT2df/qW+bDfqxrGafoaGcqBoOGhB m9uNY41g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:43748) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1x2Ab3-0000000013P-2RN0; Thu, 03 Sep 2026 17:47:29 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1x2Aay-000000007Y3-2v7X; Thu, 03 Sep 2026 17:47:24 +0100 Date: Thu, 3 Sep 2026 17:47:24 +0100 From: Russell King To: Sebastian Andrzej Siewior Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-perf-users@vger.kernel.org, loongarch@lists.linux.dev, Mark Rutland , Ian Rogers , Peter Zijlstra , "Luis Claudio R. Goncalves" , Catalin Marinas , James Clark , Huacai Chen , Adrian Hunter , Steven Rostedt , Oleg Nesterov , Alexander Shishkin , Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , Namhyung Kim , Waiman Long , WANG Xuerui , Will Deacon , Clark Williams Subject: Re: [PATCH v2] ARM, ARM64, LONGARCH: Delay HW BP notification to task_work() Message-ID: References: <20260814085118.OPEA_Ssn@linutronix.de> <20260903160710.vVf4gEL2@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260903160710.vVf4gEL2@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260903_094738_432298_77B64FF4 X-CRM114-Status: GOOD ( 20.40 ) 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, Sep 03, 2026 at 06:07:10PM +0200, Sebastian Andrzej Siewior wrote: > On 2026-08-14 10:51:18 [+0200], To linux-arm-kernel@lists.infradead.org wrote: > > Waiman, Luis, Ada reported that HW breakpoints on ARM64 trigger > > "sleeping while atomic" warnings on PREEMPT_RT. The hardware event is > > delivered with disabled interrupts and perf intrastrucure expects > > disabled interrupts while the overflow callback is invoked. > > > > The callback then sends a SIGTRAP signal for which it acquires > > sighand_struct::siglock, a spinlock_t which becomes a sleeping lock and > > must not be acquired in atomic context. > > > > Delay the event callback until the return to userland. > > Add perf_arch_hwbp_notify(), a generic perf callback which delayes the > > actual callback invocation to task_work_add() callback. This callback > > invokes the architecture defines callback arch_hwbp_send_sig(). > > This requires struct callback_head and the functions require > > ARCH_NEED_PERF_HW_NOTIF to be defined. > > > > This was reported against ARM64. ARM and LongARCH follow the same > > pattern are also converted. > > > > Reported-by: Luis Claudio R. Goncalves > > Reported-by: Waiman Long > > Closes: https://lore.kernel.org/all/aho0eqjMESuHxECr@redhat.com/ > > Signed-off-by: Sebastian Andrzej Siewior > > Did this get lost, should I repost it or is there something obviously > wrong with it and nobody wanted to hurt my feelings by telling me? What do you expect to happen with this? Which arch maintainer should apply this patch that affects three different independently maintained architectures? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!