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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 388A9C433F5 for ; Mon, 15 Nov 2021 17:55:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D652463428 for ; Mon, 15 Nov 2021 17:55:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D652463428 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 682516B007B; Mon, 15 Nov 2021 12:55:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6316A6B007D; Mon, 15 Nov 2021 12:55:46 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 522456B007E; Mon, 15 Nov 2021 12:55:46 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0176.hostedemail.com [216.40.44.176]) by kanga.kvack.org (Postfix) with ESMTP id 3F0C46B007B for ; Mon, 15 Nov 2021 12:55:46 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0536684D07 for ; Mon, 15 Nov 2021 17:55:46 +0000 (UTC) X-FDA: 78811917282.19.FE7D6D0 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf19.hostedemail.com (Postfix) with ESMTP id 32767B000188 for ; Mon, 15 Nov 2021 17:55:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S8QU5CKAf2F09vTBEAu41rD8RMni9mSF8OXKxlexhR8=; b=eLHzUXPqJxEHueyrimRTWGKmOc Pl0zqL9Pkz7vJTfnlnz8cpm918KHErxdacyVEDoKnu3s6/edXUVT1gv8fZP3DcGaMiS/FX8lPbT8l wFBxcNQs6tbK5w+oXZi6owYmWzZiVeg+ZXVSCtWI1Pv2pqYC+vdpnfDKepmj6fg8T+3nhf6JEdzpO YBBSUDt1r4ToFfi/VtSELsL8yXMSGvfOPEPhD1elZ/4zD59Th773Q3RlmFtjUzv/bIQNEpqueMtpL +M8lCpo+iB0b+Pjk7xtO6oGRBXBzH7hu1hTG883LAE/l0oZ8CRUSDPXA99ojFgWyPvehdSTAqoUDi JQXZ293Q==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mmgCd-005uGj-0d; Mon, 15 Nov 2021 17:55:35 +0000 Date: Mon, 15 Nov 2021 17:55:34 +0000 From: Matthew Wilcox To: Alistair Popple Cc: akpm@linux-foundation.org, dhowells@redhat.com, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, jgg@nvidia.com, rcampbell@nvidia.com, jhubbard@nvidia.com Subject: Re: [PATCH v3] mm/migrate.c: Rework migration_entry_wait() to not take a pageref Message-ID: References: <20211115105222.4183286-1-apopple@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211115105222.4183286-1-apopple@nvidia.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 32767B000188 X-Stat-Signature: o7xf4wukxmswjayobpzoexneo9dtbpr6 Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=eLHzUXPq; spf=none (imf19.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-HE-Tag: 1636998935-938369 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: On Mon, Nov 15, 2021 at 09:52:22PM +1100, Alistair Popple wrote: > +#ifdef CONFIG_MIGRATION > +/** > + * migration_entry_wait_on_locked - Wait for a migration entry to be removed > + * @page: page referenced by the migration entry. This should be @folio (you can test by running 'make htmldocs', or even 'make W=1' > + * @ptep: mapped pte pointer. This function will return with the ptep unmapped. > + * @ptl: already locked ptl. This function will drop the lock. > + * > + * Wait for a migration entry referencing the given page to be removed. This is > + * equivalent to put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE) except > + * this can be called without taking a reference on the page. Instead this > + * should be called while holding the ptl for the migration entry referencing > + * the page. The tool won't tell you to update these page references to be folio references ... so I will ;-) > +++ b/mm/migrate.c > @@ -305,15 +305,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > page = pfn_swap_entry_to_page(entry); > page = compound_head(page); I think this whole function should be folio-based. That is: - struct page *page; + struct folio *folio; and folio = page_folio(pfn_swap_entry_to_page(entry));