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 B3BB7CD98C7 for ; Mon, 15 Jun 2026 11:49:34 +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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=NqRcBEf3cpBlAxRxD81om6Hb6nO5tAf5Wi1yiOZJ8GE=; b=eQqljFFYL8lFTs+kztQ6JSTnAw YCzsNiem1OWMZ9EhZo81SsvFJf+LMzTg0X3D95Lp9wiHy4ywX0PPGGXM8H1tdO3VcSEfqWjC54Li0 8w3BmR6mHo/QFKVwe9iYAUVllO4S7gJUgEL2BcsOTMmQf7gwO7amDzzv9dVa/h7Ly6LIyTrsTfEM5 xZxsLZEg0MrlBjlDpI+qE0DfrZZVDz2uRsaITA/xYot2CwTdgxghF68AeSogVGmmKbJ+qP/MoL3qt RyHF4w/sAJSh33fsewAAinzNb0xx/uUPYKUeV/QYv3o4p74GFLtJGXCzby9LgWE7+p8wqGqky1Hwh FPiGOqVA==; 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charset=UTF-8 Content-Transfer-Encoding: 7bit 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 6/14/26 22:29, Tejun Heo wrote: > Hello, > > On Sun, Jun 14, 2026 at 10:28:02AM +0100, Will Deacon wrote: >>> +/* >>> + * Note: strictly-zero compare is narrower than pte_none(), but the gap is >>> + * harmless: a fresh kernel PTE has no software bits set. >>> + */ >> >> This comment really confused me :/ >> >> What is a "fresh" kernel PTE and why do you specifically call out "software >> bits" if the CAS requires all 64 bits to be 0? Why is that narrower than >> pte_none() given that pte_none() for arm64 is: >> >> #define pte_none(pte) (!pte_val(pte)) > > Yeah, that's complete non-sense for arm. The comment is about x86's > pte_none() excluding DIRTY and ACCESSED due to an erratum when testing none > and how that doesn't matter here. This shouldn't have been copied to arm. > I'll send a patch to remove that. Is BPF maybe picking up patches from other subsystems up too early without waiting for acks? -- Cheers, David