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 2B467CD6E5D for ; Tue, 2 Jun 2026 22:09:23 +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:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GC8FjW8eAZZqSEHEtIR7QWUFGmOxnTJ1Nu6ikhwgeQA=; b=IOc3IyU5bMdB06vaLOUzKEYqY+ T9feOFx2q1FowwtvwRo39++0OsB4SLXOWZcC4GFC9xHCZvrd0TurQHmQ8hGoTqS9QSXkKpGurm57d pMNIM+skmOzqEgVFpLrCDh56VIA8bIQ93bqdzgv5d/QRJEBjTpBDu69AkcjrwfE2MYn1B4CFjk3v+ LkoaXfX225IfXyef5ohm9MGxy3aIlBy/Vis3B3k4myam9PeLrJdjXmtx+m4jxzNS1ElEvbsrvUNDz KNwnKgBb5qg70bfF472Z89IlMK6H+5m5AjDoNLdtkMmYmwlwx0tJuVal2NSUFdMWohEuF90p9IFw7 7tlWikhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUXIS-0000000DrwK-0gaZ; Tue, 02 Jun 2026 22:09:16 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUXIQ-0000000DrvT-1qDI for linux-arm-kernel@lists.infradead.org; Tue, 02 Jun 2026 22:09:15 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 255BA4454F; Tue, 2 Jun 2026 22:09:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D634F1F00893; Tue, 2 Jun 2026 22:09:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780438153; bh=GC8FjW8eAZZqSEHEtIR7QWUFGmOxnTJ1Nu6ikhwgeQA=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=LezzoyJOYE8E5dHI2kTrX2OlVW8csGBo71kbltsEIXgUg7b3ekMDmNG6Bb/sOKisP mBAFZPTtkKRnHQD4pmKo5hbhuMNRyNUbc3HkAm4ILzgTZJrmEO2mPVL83QV0lxShjh p6zpwO8u9X+6fFWJDWQSKUAh5SKN43wkDR4DLRaQ00acWtw+On1hfmIWtMot7YOGsO xUGHWBXkhk/Ujm73YVH8nRDI4SCq8HH8XZzGujRj1bbkqOfqznKCS52wriKePD8x2X bcEt7+QCl4d/m8RdICey8u64NsLkzsUmcx99k6ZMKkmFyW+YpDiE98wvCCVl1FJfyo gAdpWQlO7N+AQ== Date: Tue, 02 Jun 2026 12:09:11 -1000 Message-ID: <8f133924fbf8d259340f3057e505f663@kernel.org> From: Tejun Heo To: bot+bpf-ci@kernel.org, void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, memxor@gmail.com Cc: peterz@infradead.org, catalin.marinas@arm.com, will@kernel.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, akpm@linux-foundation.org, david@kernel.org, rppt@kernel.org, emil@etsalapatis.com, sched-ext@lists.linux.dev, bpf@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, eddyz87@gmail.com, yonghong.song@linux.dev, clm@meta.com, ihor.solodrai@linux.dev Subject: Re: [PATCH bpf-next] bpf: Replace scratch PTE atomically when allocating arena pages In-Reply-To: References: <20260601183728.1800490-1-tj@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260602_150914_496208_FB4BEAD7 X-CRM114-Status: UNSURE ( 5.51 ) X-CRM114-Notice: Please train this message. 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 Mon, Jun 01, 2026 at 08:15:34PM +0000, bot+bpf-ci@kernel.org wrote: > After the real page is installed without a flush, can that stale > kaddr -> scratch_page translation persist, so that later kernel-side > accesses at kaddr reach the shared per-arena scratch page instead of > the freshly allocated page? It can on x86, but it's harmless: that CPU faulted on an unallocated address and got scratch-recovered, so reaching either the scratch or the real page is fine. No flush needed. Thanks. -- tejun