From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id A05036B0260 for ; Mon, 16 Apr 2018 22:26:07 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id y16so8225411wrh.22 for ; Mon, 16 Apr 2018 19:26:07 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id 93sor8893775edi.51.2018.04.16.19.26.06 for (Google Transport Security); Mon, 16 Apr 2018 19:26:06 -0700 (PDT) Date: Mon, 16 Apr 2018 15:51:26 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH 7/8] mm: Always check PagePolicyNoCompound Message-ID: <20180416125126.a2n5yhdamk3hvdxt@node.shutemov.name> References: <20180414043145.3953-1-willy@infradead.org> <20180414043145.3953-8-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180414043145.3953-8-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: linux-mm@kvack.org, Matthew Wilcox , "Kirill A . Shutemov" , Pavel Tatashin On Fri, Apr 13, 2018 at 09:31:44PM -0700, Matthew Wilcox wrote: > From: Matthew Wilcox > > Currently, we're only checking that a page is not compound when we're > setting or clearing a bit. We should probably be checking the page > isn't compound when testing the bit too. Well, we can definately try this, but I'm worried about false-positives in speculative code path. Maybe downgrade it WARN_ONCE() or something? -- Kirill A. Shutemov