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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED,USER_AGENT_GIT 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 363B7C433E6 for ; Thu, 25 Feb 2021 07:36:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E37CF64EF1 for ; Thu, 25 Feb 2021 07:36:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234492AbhBYHgq (ORCPT ); Thu, 25 Feb 2021 02:36:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233077AbhBYHel (ORCPT ); Thu, 25 Feb 2021 02:34:41 -0500 Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9ECB0C06178A for ; Wed, 24 Feb 2021 23:33:54 -0800 (PST) Received: by mail-pg1-x52a.google.com with SMTP id g4so3242522pgj.0 for ; Wed, 24 Feb 2021 23:33:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/5/6+cfz5gtBsby2ty8cXFbwclvAT3dDAZAxr63sxVg=; b=ibGos30OWkGhK94St7H4ygsjcHlkjiHBe5OfiXsHHCMi8KokCyS8CUUj6+jho55QZL vockORGC/YpJq4oaHSlTs5c6p1B9UfpQVf+26G/WLd1nZ974LY3hgX2NJmUkMYjVn4yQ Ujdew4CI+s0gBBq1esyGow3zdyEO1HNPG4Nu+VblemfLozhl6TfV9heeBW1Y6yda+KCG ZwNpD0fxcntbR75Z5IkbtixArbBQzph7R7+XZvt2GD9uvzBGIY8TRKfX/tfCEbRIHSV3 CC0zzYWVRQNpMJMgbcTSGTSeXhV2+TIptv1V3XkTbY/+YOAgUaVZRP9s17XEPl+cZ5HS dvEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/5/6+cfz5gtBsby2ty8cXFbwclvAT3dDAZAxr63sxVg=; b=BZrWDZkpRlxRzYJmSkLqAPSahsKhNd8XdrurhTfLbnWWhk04/qzSspx4mTD5esHUxn wkrmUUa1Rj7qu291qi8BvSVNSDa7Or9t/8UUJLwifNeSN+Vy0AI8etjen7WFlVjfV45t GaN26JhiNVDJYtoYXjmLZ/zYszgf/Gvkl4qgVOifyLwYKFzhtvMFwSoSoRhog9Ps1m92 SGormo2Y1ECGRXMui8Vbo0LvoedJca10wAfuYmx8j9OwbkhbfTD/CUAjS4wnEMzsG4UE grTou0UiQ94va8Tv6khKDI21OOAhrPB/Y5P9GB8/QU2VZkntrbarJ3S9wRjkBbKhjj0n Gmtw== X-Gm-Message-State: AOAM531aPAucRmzX+hGpZW786wFOoAxCz0BBaK6PhQw64WsNlTgSovBa BDlaspnbgT48ILc70tOYBJ8= X-Google-Smtp-Source: ABdhPJzlg70x3wr3Y1hic7wjGCwzmQfHI7U2X3bfeBjzjSYddIgrS14TA6tUsoKVfGhF8hS6lxHCYw== X-Received: by 2002:a62:1412:0:b029:1ec:bc11:31fd with SMTP id 18-20020a6214120000b02901ecbc1131fdmr1997292pfu.76.1614238434086; Wed, 24 Feb 2021 23:33:54 -0800 (PST) Received: from sc2-haas01-esx0118.eng.vmware.com ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id w3sm4917561pjt.24.2021.02.24.23.33.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Feb 2021 23:33:53 -0800 (PST) From: Nadav Amit X-Google-Original-From: Nadav Amit To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Hugh Dickins , Andy Lutomirski , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Borislav Petkov , Nadav Amit , Sean Christopherson , Andrew Morton , x86@kernel.org Subject: [RFC 4/6] mm/swap_state: respect FAULT_FLAG_RETRY_NOWAIT Date: Wed, 24 Feb 2021 23:29:08 -0800 Message-Id: <20210225072910.2811795-5-namit@vmware.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210225072910.2811795-1-namit@vmware.com> References: <20210225072910.2811795-1-namit@vmware.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nadav Amit Certain use-cases (e.g., prefetch_page()) may want to avoid polling while a page is brought from the swap. Yet, swap_cluster_readahead() and swap_vma_readahead() do not respect FAULT_FLAG_RETRY_NOWAIT. Add support to respect FAULT_FLAG_RETRY_NOWAIT by not polling in these cases. Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Sean Christopherson Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Andrew Morton Cc: x86@kernel.org Signed-off-by: Nadav Amit --- mm/memory.c | 15 +++++++++++++-- mm/shmem.c | 1 + mm/swap_state.c | 12 +++++++++--- 3 files changed, 23 insertions(+), 5 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index feff48e1465a..13b9cf36268f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3326,12 +3326,23 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) } if (!page) { + /* + * Back out if we failed to bring the page while we + * tried to avoid I/O. + */ + if (fault_flag_allow_retry_first(vmf->flags) && + (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { + ret = VM_FAULT_RETRY; + delayacct_clear_flag(DELAYACCT_PF_SWAPIN); + goto out; + } + /* * Back out if somebody else faulted in this pte * while we released the pte lock. */ - vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, - vmf->address, &vmf->ptl); + vmf->pte = pte_offset_map_lock(vma->vm_mm, + vmf->pmd, vmf->address, &vmf->ptl); if (likely(pte_same(*vmf->pte, vmf->orig_pte))) ret = VM_FAULT_OOM; delayacct_clear_flag(DELAYACCT_PF_SWAPIN); diff --git a/mm/shmem.c b/mm/shmem.c index 7c6b6d8f6c39..b108e9ba9e89 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1525,6 +1525,7 @@ static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, shmem_pseudo_vma_init(&pvma, info, index); vmf.vma = &pvma; vmf.address = 0; + vmf.flags = 0; page = swap_cluster_readahead(swap, gfp, &vmf); shmem_pseudo_vma_destroy(&pvma); diff --git a/mm/swap_state.c b/mm/swap_state.c index 751c1ef2fe0e..1e930f7ff8b3 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -656,10 +656,13 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, unsigned long mask; struct swap_info_struct *si = swp_swap_info(entry); struct blk_plug plug; - bool do_poll = true, page_allocated; + bool page_allocated, do_poll; struct vm_area_struct *vma = vmf->vma; unsigned long addr = vmf->address; + do_poll = !fault_flag_allow_retry_first(vmf->flags) || + !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT); + mask = swapin_nr_pages(offset) - 1; if (!mask) goto skip; @@ -838,7 +841,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, pte_t *pte, pentry; swp_entry_t entry; unsigned int i; - bool page_allocated; + bool page_allocated, do_poll; struct vma_swap_readahead ra_info = { .win = 1, }; @@ -873,9 +876,12 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, } blk_finish_plug(&plug); lru_add_drain(); + skip: + do_poll = (!fault_flag_allow_retry_first(vmf->flags) || + !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) && ra_info.win == 1; return read_swap_cache_async(fentry, gfp_mask, vma, vmf->address, - ra_info.win == 1); + do_poll); } /** -- 2.25.1