From patchwork Mon Nov 7 16:17:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13034788 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 27E25C433FE for ; Mon, 7 Nov 2022 16:19:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 77A0110E472; Mon, 7 Nov 2022 16:19:05 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id BCF3710E46F for ; Mon, 7 Nov 2022 16:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667837933; 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: in-reply-to:in-reply-to:references:references; bh=8LSm/ABK1dZuzbBLIy952PsCCtserHCfNmIiwyOpplI=; b=Nz/+/ROIT5/uxypnXtS3G9EQT1NL+JDKWzeVVPHeSOLBFfz5VcXWAMJ+YJi//tAmN8ufcz U9BVn/Yuv3jVCxJVQmN8yHyohfXhzyXwHSiAzUeRrwr9O4wAk5ZqnTy+zc01ti9qrGCV19 DvWPGiFNwY4WPopelT06PMoMJy1z0DA= 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-491-BzZ6c9HQOyGIJKIwV5MVVA-1; Mon, 07 Nov 2022 11:18:47 -0500 X-MC-Unique: BzZ6c9HQOyGIJKIwV5MVVA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5AA663C0F671; Mon, 7 Nov 2022 16:18:46 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.195.106]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D9544B4010; Mon, 7 Nov 2022 16:18:40 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Subject: [PATCH RFC 10/19] RDMA/umem: remove FOLL_FORCE usage Date: Mon, 7 Nov 2022 17:17:31 +0100 Message-Id: <20221107161740.144456-11-david@redhat.com> In-Reply-To: <20221107161740.144456-1-david@redhat.com> References: <20221107161740.144456-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Nadav Amit , linux-kselftest@vger.kernel.org, Andrea Arcangeli , linux-samsung-soc@vger.kernel.org, Leon Romanovsky , linux-rdma@vger.kernel.org, Hugh Dickins , Matthew Wilcox , Jason Gunthorpe , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, Arnd Bergmann , John Hubbard , etnaviv@lists.freedesktop.org, Peter Xu , Muchun Song , Vlastimil Babka , Greg Kroah-Hartman , Oded Gabbay , Andrew Morton , Linus Torvalds , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" GUP now supports reliable R/O long-term pinning in COW mappings, such that we break COW early. MAP_SHARED VMAs only use the shared zeropage so far in one corner case (DAXFS file with holes), which can be ignored because GUP does not support long-term pinning in fsdax (see check_vma_flags()). Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop using FOLL_FORCE, which is really only for debugger access. Cc: Jason Gunthorpe Cc: Leon Romanovsky Signed-off-by: David Hildenbrand Tested-by: Leon Romanovsky # Over mlx4 and mlx5. --- drivers/infiniband/core/umem.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 86d479772fbc..755a9c57db6f 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -156,7 +156,7 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, struct mm_struct *mm; unsigned long npages; int pinned, ret; - unsigned int gup_flags = FOLL_WRITE; + unsigned int gup_flags = FOLL_LONGTERM; /* * If the combination of the addr and size requested for this memory @@ -210,8 +210,8 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, cur_base = addr & PAGE_MASK; - if (!umem->writable) - gup_flags |= FOLL_FORCE; + if (umem->writable) + gup_flags |= FOLL_WRITE; while (npages) { cond_resched(); @@ -219,7 +219,7 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, min_t(unsigned long, npages, PAGE_SIZE / sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, page_list); + gup_flags, page_list); if (pinned < 0) { ret = pinned; goto umem_release;