From patchwork Thu Sep 9 21:06:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 509188 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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham 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 CA806C433EF for ; Thu, 9 Sep 2021 21:06:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B68D1611BD for ; Thu, 9 Sep 2021 21:06:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348075AbhIIVH0 (ORCPT ); Thu, 9 Sep 2021 17:07:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:57194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347720AbhIIVHQ (ORCPT ); Thu, 9 Sep 2021 17:07:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8F3CD611C1; Thu, 9 Sep 2021 21:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1631221566; bh=6OznrfSU8CgvppHSBKHoQeb/Tp2FUsfTE/w9TN4Dld4=; h=Date:From:To:Subject:From; b=kOjoXiw7hTSsCfd5TTxfmUWabvBpvviHikZTThZ3brJVKqrnQKPS0zhYP8dv1bbRc ryxRViqERVjN2xuHMHZjOsou8BqElOtWjmm2jyumFwEB3+Qmu9AdnXbbx33I8aI9a/ cHxRvnscFnmPMV9quTakT4gbe5avHZLgL2yfKMCk= Date: Thu, 09 Sep 2021 14:06:06 -0700 From: akpm@linux-foundation.org To: hch@lst.de, jgg@nvidia.com, lizhijian@cn.fujitsu.com, mm-commits@vger.kernel.org, stable@vger.kernel.org Subject: [merged] mm-hmm-bypass-devmap-pte-when-all-pfn-requested-flags-are-fulfilled.patch removed from -mm tree Message-ID: <20210909210606.XTkF9krFI%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled has been removed from the -mm tree. Its filename was mm-hmm-bypass-devmap-pte-when-all-pfn-requested-flags-are-fulfilled.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Li Zhijian Subject: mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled Previously, we noticed the one rpma example was failed[1] since 36f30e486d, where it will use ODP feature to do RDMA WRITE between fsdax files. After digging into the code, we found hmm_vma_handle_pte() will still return EFAULT even though all the its requesting flags has been fulfilled. That's because a DAX page will be marked as (_PAGE_SPECIAL | PAGE_DEVMAP) by pte_mkdevmap(). [1]: https://github.com/pmem/rpma/issues/1142 Link: https://lkml.kernel.org/r/20210830094232.203029-1-lizhijian@cn.fujitsu.com Fixes: 405506274922 ("mm/hmm: add missing call to hmm_pte_need_fault in HMM_PFN_SPECIAL handling") Signed-off-by: Li Zhijian Reviewed-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Cc: Signed-off-by: Andrew Morton --- mm/hmm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/hmm.c~mm-hmm-bypass-devmap-pte-when-all-pfn-requested-flags-are-fulfilled +++ a/mm/hmm.c @@ -295,10 +295,13 @@ static int hmm_vma_handle_pte(struct mm_ goto fault; /* + * Bypass devmap pte such as DAX page when all pfn requested + * flags(pfn_req_flags) are fulfilled. * Since each architecture defines a struct page for the zero page, just * fall through and treat it like a normal page. */ - if (pte_special(pte) && !is_zero_pfn(pte_pfn(pte))) { + if (pte_special(pte) && !pte_devmap(pte) && + !is_zero_pfn(pte_pfn(pte))) { if (hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0)) { pte_unmap(ptep); return -EFAULT;