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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C495C56202 for ; Tue, 27 Oct 2020 16:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 437582225C for ; Tue, 27 Oct 2020 16:26:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603816003; bh=lEenNJwcj7aiDKZ/VZCzrtAUrtSwegt0ZisP4SpaTgA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DgBUSyBZ5t86XiXCOjZtyk4+GGGM2OLCTUE8a2OrYnmgMZtMf9onc6fUGTlfNQypm KZjBZC+4zTbaFFZoP2oMspR2hQAyc9jXAeNh6s//7J3Lak/mxC10IE1CM4KKR30SvT gh3DKLYW/qd2iRyCvDJKRVwf3BACA8U05gKHYJjY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1803088AbgJ0PwJ (ORCPT ); Tue, 27 Oct 2020 11:52:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:57270 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1801057AbgJ0PiH (ORCPT ); Tue, 27 Oct 2020 11:38:07 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 78C76204EF; Tue, 27 Oct 2020 15:38:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603813085; bh=lEenNJwcj7aiDKZ/VZCzrtAUrtSwegt0ZisP4SpaTgA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1EOMqHWu8N8zXhg/1I0Go8PSYk4GoDHKPE8qdyfY3Du9bBTXkKwJ55hG+TkMuUsAf m+WG/QHXggHxmK7WTQehTudM5J3Di5zBDVHWkvQxA+c/Ly5Z6t7JY50WmenI74cPOQ HhERpGe9MyRJO6AUBYX0KdyisJwlX1RbgptmBesw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Leon Romanovsky , Shiraz Saleem , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.9 432/757] RDMA/umem: Fix ib_umem_find_best_pgsz() for mappings that cross a page boundary Date: Tue, 27 Oct 2020 14:51:22 +0100 Message-Id: <20201027135510.820184184@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Gunthorpe [ Upstream commit a40c20dabdf9045270767c75918feb67f0727c89 ] It is possible for a single SGL to span an aligned boundary, eg if the SGL is 61440 -> 90112 Then the length is 28672, which currently limits the block size to 32k. With a 32k page size the two covering blocks will be: 32768->65536 and 65536->98304 However, the correct answer is a 128K block size which will span the whole 28672 bytes in a single block. Instead of limiting based on length figure out which high IOVA bits don't change between the start and end addresses. That is the highest useful page size. Fixes: 4a35339958f1 ("RDMA/umem: Add API to find best driver supported page size in an MR") Link: https://lore.kernel.org/r/1-v2-270386b7e60b+28f4-umem_1_jgg@nvidia.com Reviewed-by: Leon Romanovsky Reviewed-by: Shiraz Saleem Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/umem.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 831bff8d52e54..09539dd764ec0 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -156,8 +156,13 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, return 0; va = virt; - /* max page size not to exceed MR length */ - mask = roundup_pow_of_two(umem->length); + /* The best result is the smallest page size that results in the minimum + * number of required pages. Compute the largest page size that could + * work based on VA address bits that don't change. + */ + mask = pgsz_bitmap & + GENMASK(BITS_PER_LONG - 1, + bits_per((umem->length - 1 + virt) ^ virt)); /* offset into first SGL */ pgoff = umem->address & ~PAGE_MASK; -- 2.25.1