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Fri, 10 Nov 2023 00:56:52 +0000 (UTC) X-FDA: 81440229864.27.2C521AB Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf04.hostedemail.com (Postfix) with ESMTP id AFD3040017 for ; Fri, 10 Nov 2023 00:56:50 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf04.hostedemail.com: domain of "SRS0=CZI1=GX=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=CZI1=GX=goodmis.org=rostedt@kernel.org" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1699577810; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9ydMPsj+Ugs/lfThLPXhGh5N5M8vZdpZOUF66Mje05w=; b=H4BkYx8+7/KhYS+McRb2NPpaRkCy1dUXh2KKIgI+cXGdYmUBPeilWlzgJH8768el3NbFYP 7DXAI3wPQhrFOuWkXrIA/iDuMN2SCrrDEg+Ra6w9FILHbXDllpmjumQA2VNrKZFCI5T8ly 4h4iizN1vHZN8Yy04CNT8Sxcgh41GQ8= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf04.hostedemail.com: domain of "SRS0=CZI1=GX=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=CZI1=GX=goodmis.org=rostedt@kernel.org" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1699577810; a=rsa-sha256; cv=none; b=Ob/1VWeqVJYUgWa6PM87KXqoxAgPNxvuv/dHXgkUxakuS9X3o195fycCe6Aim/nl/PijEs WkMIT+wtCnfZ45ZaYlj5SIpmzNVOD6VApSUAtIfXyJ215uUMeqKRypccN9gsNw26UPVhRH cKw6MRZjJPOGebOZnENIWzxBuDBAnIE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A16B360C54; Fri, 10 Nov 2023 00:56:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F4F5C433C8; Fri, 10 Nov 2023 00:56:45 +0000 (UTC) Date: Thu, 9 Nov 2023 19:56:49 -0500 From: Steven Rostedt To: Josh Poimboeuf Cc: Ankur Arora , linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, paulmck@kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, mingo@kernel.org, bristot@kernel.org, mathieu.desnoyers@efficios.com, geert@linux-m68k.org, glaubitz@physik.fu-berlin.de, anton.ivanov@cambridgegreys.com, mattst88@gmail.com, krypton@ulrich-teichert.org, David.Laight@ACULAB.COM, richard@nod.at, mjguzik@gmail.com, Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , live-patching@vger.kernel.org Subject: Re: [RFC PATCH 07/86] Revert "livepatch,sched: Add livepatch task switching to cond_resched()" Message-ID: <20231109195649.2b2869fc@gandalf.local.home> In-Reply-To: <20231109175118.olggitpaltz47n3b@treble> References: <20231107215742.363031-1-ankur.a.arora@oracle.com> <20231107215742.363031-8-ankur.a.arora@oracle.com> <20231107181609.7e9e9dcc@gandalf.local.home> <20231109172637.ayue3jexgdxd53tu@treble> <20231109123147.2bb11809@gandalf.local.home> <20231109175118.olggitpaltz47n3b@treble> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: AFD3040017 X-Stat-Signature: 1a5z6ybx5u874a9s9gjtt1w1i7hqdk3o X-HE-Tag: 1699577810-901800 X-HE-Meta: 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 78Se7yUz c4iX1gr0LP1FAlbQA6yViV9clVcKBGSJ2CjamwuTn8cLSwLzUoHXVOn2cWSu7Q9U/dTFlNqAAPC6XMyOtbPqsjgEsxVjuBDaoaHak30F6o4FJM21/CQ3pkxt9knnudhVq4p0i8RJKHxWAdwv+LAjLR0xTf/OMHpKU0+ot36csp1JCIjcJoWNyqJbUKH7IrH+1ktpj1UwaatRN4UmoBrQUdyRn5WugIi/bjBl44Nr5U3Ct+D5v2SjdG1aCATgtK/GuBNb79ABdcAVkifig2JsNlgbn5ssxhwSnB6dlUKnxzhHDn9j57B47hchwtw5QSRWadcs9E6pQBZsSSlrN1efORhJ/XaS0DhJfkYkNOKinmQPN1fI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 9 Nov 2023 09:51:18 -0800 Josh Poimboeuf wrote: > > I guess I'm not fully understanding what the cond rescheds are for. But > > would an IPI to all CPUs setting NEED_RESCHED, fix it? > > If all livepatch arches had the ORC unwinder, yes. > > The problem is that frame pointer (and similar) unwinders can't reliably > unwind past an interrupt frame. Perhaps we can use this to push those archs with bad unwinders to port over ORC unwinding ;-) -- Steve