From patchwork Tue May 26 19:51:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 11571185 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 979F9913 for ; Tue, 26 May 2020 19:52:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80AEF208DB for ; Tue, 26 May 2020 19:52:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="YKbLOw6L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390491AbgEZTw2 (ORCPT ); Tue, 26 May 2020 15:52:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390240AbgEZTvb (ORCPT ); Tue, 26 May 2020 15:51:31 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFD76C03E96D for ; Tue, 26 May 2020 12:51:30 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id k22so9111866pls.10 for ; Tue, 26 May 2020 12:51:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=fQihCl0dLbHaElgiRrlXkibi9/E8OKsaJ7lF0uUyO/s=; b=YKbLOw6LpYloCfEz6cSjXDp7lo/SEH14850NuBSfnHJZqbSNda9ft1KrD9kDTlgX29 i5p9OTzKmGtxOrMHS+JBQto/yzM9zXGeRvk09gakJOY0/1BHuWAqj05obqvWTcQqZXjM tSs3FQLGux7Ieod96lB3tb6zv/Ei+e+rH+jvFEsgFfzk6f2Q6xviMQedqciMUxeS5bww YudmGt61FcA28hKFe3zbgPJZzUu27iwTT39ESm3iUzvAQWSmULv85wglM46pdLh9xw2G 2vQ4GSnPWkUwbN9Hsml5BFWibSXp84PL/jR8cl2CQ0mI7mUEGk1xtvkYObM/1b+lAY5j 3Wiw== 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=fQihCl0dLbHaElgiRrlXkibi9/E8OKsaJ7lF0uUyO/s=; b=BmIhMFSRt9k3gQ6D+8neLcWVqxe78pFEyv/9M/yGmpTXFpwwEIQUoHxN7ZtvVW4Jkm LBez7nMQpPDcsGZzuTMr6L2g9DErZdos6RizHgi4V/Bnjh1Lg3H2VH4KLbYPZoIMC9Br efkTjYV7w69Dumxrd+0IBy1gfGbAqVsDabhdrOCu+KTQvgJ6B1R68/iqUfWiIBE/XFLX uVmdw4UJ4I34V+Av3xhI2Z8XvNXm3ahZ5KoeD0GOx8d0rUgj55tezlkzteqgHek5EvXa w/XDAjP3pI1Fn/3Kx2WkhSt0D4cOy2U+E5C+Zy+b7WmVXeGc81PHv2boNIiXdOYZeVui jgFg== X-Gm-Message-State: AOAM533i6blyr4T+PE3Syg0+/U2+azjHAAtrbGeZRiLiYpdXAIHHdrZx tc7/i2HgQ+WKUe8qyXoMupk/Tg== X-Google-Smtp-Source: ABdhPJyeEiZx5SIpedWyfYllR0duff8tGiFVV6KjQ7XygtXqKPG6eKYMQBb6I07aOaSUrZejp48HpQ== X-Received: by 2002:a17:90a:f283:: with SMTP id fs3mr874913pjb.1.1590522690209; Tue, 26 May 2020 12:51:30 -0700 (PDT) Received: from x1.lan ([2605:e000:100e:8c61:94bb:59d2:caf6:70e1]) by smtp.gmail.com with ESMTPSA id c184sm313943pfc.57.2020.05.26.12.51.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 12:51:29 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, Jens Axboe Subject: [PATCH 03/12] mm: abstract out wake_page_match() from wake_page_function() Date: Tue, 26 May 2020 13:51:14 -0600 Message-Id: <20200526195123.29053-4-axboe@kernel.dk> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526195123.29053-1-axboe@kernel.dk> References: <20200526195123.29053-1-axboe@kernel.dk> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org No functional changes in this patch, just in preparation for allowing more callers. Signed-off-by: Jens Axboe Acked-by: Johannes Weiner --- include/linux/pagemap.h | 37 +++++++++++++++++++++++++++++++++++++ mm/filemap.c | 35 ++++------------------------------- 2 files changed, 41 insertions(+), 31 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index a8f7bd8ea1c6..53d980f2208d 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -456,6 +456,43 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma, return pgoff; } +/* This has the same layout as wait_bit_key - see fs/cachefiles/rdwr.c */ +struct wait_page_key { + struct page *page; + int bit_nr; + int page_match; +}; + +struct wait_page_queue { + struct page *page; + int bit_nr; + wait_queue_entry_t wait; +}; + +static inline int wake_page_match(struct wait_page_queue *wait_page, + struct wait_page_key *key) +{ + if (wait_page->page != key->page) + return 0; + key->page_match = 1; + + if (wait_page->bit_nr != key->bit_nr) + return 0; + + /* + * Stop walking if it's locked. + * Is this safe if put_and_wait_on_page_locked() is in use? + * Yes: the waker must hold a reference to this page, and if PG_locked + * has now already been set by another task, that task must also hold + * a reference to the *same usage* of this page; so there is no need + * to walk on to wake even the put_and_wait_on_page_locked() callers. + */ + if (test_bit(key->bit_nr, &key->page->flags)) + return -1; + + return 1; +} + extern void __lock_page(struct page *page); extern int __lock_page_killable(struct page *page); extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm, diff --git a/mm/filemap.c b/mm/filemap.c index 80747f1377d5..e891b5bee8fd 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -990,43 +990,16 @@ void __init pagecache_init(void) page_writeback_init(); } -/* This has the same layout as wait_bit_key - see fs/cachefiles/rdwr.c */ -struct wait_page_key { - struct page *page; - int bit_nr; - int page_match; -}; - -struct wait_page_queue { - struct page *page; - int bit_nr; - wait_queue_entry_t wait; -}; - static int wake_page_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *arg) { struct wait_page_key *key = arg; struct wait_page_queue *wait_page = container_of(wait, struct wait_page_queue, wait); + int ret; - if (wait_page->page != key->page) - return 0; - key->page_match = 1; - - if (wait_page->bit_nr != key->bit_nr) - return 0; - - /* - * Stop walking if it's locked. - * Is this safe if put_and_wait_on_page_locked() is in use? - * Yes: the waker must hold a reference to this page, and if PG_locked - * has now already been set by another task, that task must also hold - * a reference to the *same usage* of this page; so there is no need - * to walk on to wake even the put_and_wait_on_page_locked() callers. - */ - if (test_bit(key->bit_nr, &key->page->flags)) - return -1; - + ret = wake_page_match(wait_page, key); + if (ret != 1) + return ret; return autoremove_wake_function(wait, mode, sync, key); }