From nobody Mon Apr 6 23:07:00 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50325ECAAD1 for ; Thu, 1 Sep 2022 07:24:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233240AbiIAHYB (ORCPT ); Thu, 1 Sep 2022 03:24:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233767AbiIAHW7 (ORCPT ); Thu, 1 Sep 2022 03:22:59 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7C441257E0 for ; Thu, 1 Sep 2022 00:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662016890; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=NlolkOVzROxrmysLyLOweRyR0NiCeVgfH2ZsqTw7uYI=; b=F7Esdy/WcrEJ/RxHhD5yHprtYomEa3e6TZhgtm+ldYuoSvm6Hsap9UVFO7Drjq18t/ueNu HrrlAvidM8+N1JTgNsUxX5pBnk9y30RElHRw+RMVQUWTeuZAeJuZbOSrSYl0OofHlPoRCE kXNipslwm5T7jeenMeXvtWg8b+UR6Y8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-451-FLn326K1NgqpnOVgPbYwKg-1; Thu, 01 Sep 2022 03:21:25 -0400 X-MC-Unique: FLn326K1NgqpnOVgPbYwKg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8FC623802127; Thu, 1 Sep 2022 07:21:24 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.132]) by smtp.corp.redhat.com (Postfix) with ESMTP id 607891121314; Thu, 1 Sep 2022 07:21:21 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, David Hildenbrand , "Kirill A . Shutemov" , Sasha Levin , "Aneesh Kumar K . V" , Vlastimil Babka , Jerome Marchand , Andrea Arcangeli , Hugh Dickins , Jason Gunthorpe , John Hubbard , Peter Xu , Yang Shi Subject: [PATCH v1] mm/gup: adjust stale comment for RCU GUP-fast Date: Thu, 1 Sep 2022 09:21:19 +0200 Message-Id: <20220901072119.37588-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" commit 4b471e8898c3 ("mm, thp: remove infrastructure for handling splitting PMDs") didn't remove all details about the THP split requirements for RCU GUP-fast. IPI broeadcasts on THP split are no longer required. Cc: Kirill A. Shutemov Cc: Sasha Levin Cc: Aneesh Kumar K.V Cc: Vlastimil Babka Cc: Jerome Marchand Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: Peter Xu Cc: Yang Shi Signed-off-by: David Hildenbrand Acked-by: Kirill A. Shutemov Reviewed-by: Jason Gunthorpe --- mm/gup.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 5abdaf487460..cfe71f422787 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2309,9 +2309,8 @@ EXPORT_SYMBOL(get_user_pages_unlocked); * * Another way to achieve this is to batch up page table containing pages * belonging to more than one mm_user, then rcu_sched a callback to free t= hose - * pages. Disabling interrupts will allow the fast_gup walker to both block - * the rcu_sched callback, and an IPI that we broadcast for splitting THPs - * (which is a relatively rare event). The code below adopts this strategy. + * pages. Disabling interrupts will allow the fast_gup walker to block the + * rcu_sched callback. * * Before activating this code, please be aware that the following assumpt= ions * are currently made: --=20 2.37.1