From patchwork Tue Jun 22 11:41:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12337037 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 64810C2B9F4 for ; Tue, 22 Jun 2021 12:07:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1283C60FF1 for ; Tue, 22 Jun 2021 12:07:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1283C60FF1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AD2136B0074; Tue, 22 Jun 2021 08:07:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A5B466B0075; Tue, 22 Jun 2021 08:07:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8ADFF6B0078; Tue, 22 Jun 2021 08:07:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0059.hostedemail.com [216.40.44.59]) by kanga.kvack.org (Postfix) with ESMTP id 580D66B0074 for ; Tue, 22 Jun 2021 08:07:13 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id E8DC58249980 for ; Tue, 22 Jun 2021 12:07:12 +0000 (UTC) X-FDA: 78281234304.02.899D84F Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf11.hostedemail.com (Postfix) with ESMTP id 8096820015EA for ; Tue, 22 Jun 2021 12:07:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=cBBD/Zg/jMD6A3P2saI7wJvKsN45hcluMiCq/Ojo3+M=; b=BtOfRPTh6OGcP4hBH174kTuhOO sIkTBxtpNsSw/WSy5acOR4HBwBPSsVft0lMP+/zhM7d+zVzl0pLRAKZMFsDMpRYM8KmfEzZK0LxWK eXvn4ITvYaS0/kR4YDtTf05GcxjfkfyASQwOpAxxtXL3T3Ucc2+sTQVN4b3lTvQ6taHKCL9qa9jrP hvryxvCBrcCVOZSa+8LQtvJCj4csIberUVbyR+Jcn6zOQMRJPdCf3DkQ5khpjRB1lufwhz/I+sknp wQZgZrdhTaO9W/z6LApUzd1wafC/opVLbFgwSf2+oCWMJqmb8GJWN4srwREtDxC55SSwFZJmWEOLO 22b9f4UA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lvf9b-00EFH7-1g; Tue, 22 Jun 2021 12:05:42 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Layton , "Kirill A . Shutemov" , Vlastimil Babka , William Kucharski , David Howells Subject: [PATCH v12 28/33] mm/filemap: Add folio_wait_bit() Date: Tue, 22 Jun 2021 12:41:13 +0100 Message-Id: <20210622114118.3388190-29-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210622114118.3388190-1-willy@infradead.org> References: <20210622114118.3388190-1-willy@infradead.org> MIME-Version: 1.0 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=BtOfRPTh; spf=none (imf11.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Stat-Signature: ikr5p3q8mnj4xecw476mthiwg1zawgs1 X-Rspamd-Queue-Id: 8096820015EA X-Rspamd-Server: rspam06 X-HE-Tag: 1624363632-210017 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Rename wait_on_page_bit() to folio_wait_bit(). We must always wait on the folio, otherwise we won't be woken up due to the tail page hashing to a different bucket from the head page. This commit shrinks the kernel by 770 bytes, mostly due to moving the page waitqueue lookup into folio_wait_bit_common(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: David Howells --- include/linux/pagemap.h | 10 +++--- mm/filemap.c | 77 +++++++++++++++++++---------------------- mm/page-writeback.c | 4 +-- 3 files changed, 43 insertions(+), 48 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index cea2abf8a08f..34180fca2892 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -728,11 +728,11 @@ static inline bool lock_page_or_retry(struct page *page, struct mm_struct *mm, } /* - * This is exported only for wait_on_page_locked/wait_on_page_writeback, etc., + * This is exported only for folio_wait_locked/folio_wait_writeback, etc., * and should not be used directly. */ -extern void wait_on_page_bit(struct page *page, int bit_nr); -extern int wait_on_page_bit_killable(struct page *page, int bit_nr); +void folio_wait_bit(struct folio *folio, int bit_nr); +int folio_wait_bit_killable(struct folio *folio, int bit_nr); /* * Wait for a folio to be unlocked. @@ -744,14 +744,14 @@ extern int wait_on_page_bit_killable(struct page *page, int bit_nr); static inline void folio_wait_locked(struct folio *folio) { if (folio_locked(folio)) - wait_on_page_bit(&folio->page, PG_locked); + folio_wait_bit(folio, PG_locked); } static inline int folio_wait_locked_killable(struct folio *folio) { if (!folio_locked(folio)) return 0; - return wait_on_page_bit_killable(&folio->page, PG_locked); + return folio_wait_bit_killable(folio, PG_locked); } static inline void wait_on_page_locked(struct page *page) diff --git a/mm/filemap.c b/mm/filemap.c index c99f60f0e93b..79cf4a788326 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1102,7 +1102,7 @@ static int wake_page_function(wait_queue_entry_t *wait, unsigned mode, int sync, * * So update the flags atomically, and wake up the waiter * afterwards to avoid any races. This store-release pairs - * with the load-acquire in wait_on_page_bit_common(). + * with the load-acquire in folio_wait_bit_common(). */ smp_store_release(&wait->flags, flags | WQ_FLAG_WOKEN); wake_up_state(wait->private, mode); @@ -1183,7 +1183,7 @@ static void folio_wake(struct folio *folio, int bit) } /* - * A choice of three behaviors for wait_on_page_bit_common(): + * A choice of three behaviors for folio_wait_bit_common(): */ enum behavior { EXCLUSIVE, /* Hold ref to page and take the bit when woken, like @@ -1198,16 +1198,16 @@ enum behavior { }; /* - * Attempt to check (or get) the page bit, and mark us done + * Attempt to check (or get) the folio flag, and mark us done * if successful. */ -static inline bool trylock_page_bit_common(struct page *page, int bit_nr, +static inline bool folio_trylock_flag(struct folio *folio, int bit_nr, struct wait_queue_entry *wait) { if (wait->flags & WQ_FLAG_EXCLUSIVE) { - if (test_and_set_bit(bit_nr, &page->flags)) + if (test_and_set_bit(bit_nr, &folio->flags)) return false; - } else if (test_bit(bit_nr, &page->flags)) + } else if (test_bit(bit_nr, &folio->flags)) return false; wait->flags |= WQ_FLAG_WOKEN | WQ_FLAG_DONE; @@ -1217,9 +1217,10 @@ static inline bool trylock_page_bit_common(struct page *page, int bit_nr, /* How many times do we accept lock stealing from under a waiter? */ int sysctl_page_lock_unfairness = 5; -static inline int wait_on_page_bit_common(wait_queue_head_t *q, - struct page *page, int bit_nr, int state, enum behavior behavior) +static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, + int state, enum behavior behavior) { + wait_queue_head_t *q = page_waitqueue(&folio->page); int unfairness = sysctl_page_lock_unfairness; struct wait_page_queue wait_page; wait_queue_entry_t *wait = &wait_page.wait; @@ -1228,8 +1229,8 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, unsigned long pflags; if (bit_nr == PG_locked && - !PageUptodate(page) && PageWorkingset(page)) { - if (!PageSwapBacked(page)) { + !folio_uptodate(folio) && folio_workingset(folio)) { + if (!folio_swapbacked(folio)) { delayacct_thrashing_start(); delayacct = true; } @@ -1239,7 +1240,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, init_wait(wait); wait->func = wake_page_function; - wait_page.page = page; + wait_page.page = &folio->page; wait_page.bit_nr = bit_nr; repeat: @@ -1254,7 +1255,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, * Do one last check whether we can get the * page bit synchronously. * - * Do the SetPageWaiters() marking before that + * Do the folio_set_waiters_flag() marking before that * to let any waker we _just_ missed know they * need to wake us up (otherwise they'll never * even go to the slow case that looks at the @@ -1265,8 +1266,8 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, * lock to avoid races. */ spin_lock_irq(&q->lock); - SetPageWaiters(page); - if (!trylock_page_bit_common(page, bit_nr, wait)) + folio_set_waiters_flag(folio); + if (!folio_trylock_flag(folio, bit_nr, wait)) __add_wait_queue_entry_tail(q, wait); spin_unlock_irq(&q->lock); @@ -1276,10 +1277,10 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, * see whether the page bit testing has already * been done by the wake function. * - * We can drop our reference to the page. + * We can drop our reference to the folio. */ if (behavior == DROP) - put_page(page); + folio_put(folio); /* * Note that until the "finish_wait()", or until @@ -1316,7 +1317,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, * * And if that fails, we'll have to retry this all. */ - if (unlikely(test_and_set_bit(bit_nr, &page->flags))) + if (unlikely(test_and_set_bit(bit_nr, folio_flags(folio, 0)))) goto repeat; wait->flags |= WQ_FLAG_DONE; @@ -1325,7 +1326,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, /* * If a signal happened, this 'finish_wait()' may remove the last - * waiter from the wait-queues, but the PageWaiters bit will remain + * waiter from the wait-queues, but the folio_waiters bit will remain * set. That's ok. The next wakeup will take care of it, and trying * to do it here would be difficult and prone to races. */ @@ -1356,19 +1357,17 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q, return wait->flags & WQ_FLAG_WOKEN ? 0 : -EINTR; } -void wait_on_page_bit(struct page *page, int bit_nr) +void folio_wait_bit(struct folio *folio, int bit_nr) { - wait_queue_head_t *q = page_waitqueue(page); - wait_on_page_bit_common(q, page, bit_nr, TASK_UNINTERRUPTIBLE, SHARED); + folio_wait_bit_common(folio, bit_nr, TASK_UNINTERRUPTIBLE, SHARED); } -EXPORT_SYMBOL(wait_on_page_bit); +EXPORT_SYMBOL(folio_wait_bit); -int wait_on_page_bit_killable(struct page *page, int bit_nr) +int folio_wait_bit_killable(struct folio *folio, int bit_nr) { - wait_queue_head_t *q = page_waitqueue(page); - return wait_on_page_bit_common(q, page, bit_nr, TASK_KILLABLE, SHARED); + return folio_wait_bit_common(folio, bit_nr, TASK_KILLABLE, SHARED); } -EXPORT_SYMBOL(wait_on_page_bit_killable); +EXPORT_SYMBOL(folio_wait_bit_killable); /** * put_and_wait_on_page_locked - Drop a reference and wait for it to be unlocked @@ -1385,11 +1384,8 @@ EXPORT_SYMBOL(wait_on_page_bit_killable); */ int put_and_wait_on_page_locked(struct page *page, int state) { - wait_queue_head_t *q; - - page = compound_head(page); - q = page_waitqueue(page); - return wait_on_page_bit_common(q, page, PG_locked, state, DROP); + return folio_wait_bit_common(page_folio(page), PG_locked, state, + DROP); } /** @@ -1483,9 +1479,10 @@ EXPORT_SYMBOL(end_page_private_2); */ void wait_on_page_private_2(struct page *page) { - page = compound_head(page); - while (PagePrivate2(page)) - wait_on_page_bit(page, PG_private_2); + struct folio *folio = page_folio(page); + + while (folio_private_2(folio)) + folio_wait_bit(folio, PG_private_2); } EXPORT_SYMBOL(wait_on_page_private_2); @@ -1502,11 +1499,11 @@ EXPORT_SYMBOL(wait_on_page_private_2); */ int wait_on_page_private_2_killable(struct page *page) { + struct folio *folio = page_folio(page); int ret = 0; - page = compound_head(page); - while (PagePrivate2(page)) { - ret = wait_on_page_bit_killable(page, PG_private_2); + while (folio_private_2(folio)) { + ret = folio_wait_bit_killable(folio, PG_private_2); if (ret < 0) break; } @@ -1583,16 +1580,14 @@ EXPORT_SYMBOL_GPL(page_endio); */ void __folio_lock(struct folio *folio) { - wait_queue_head_t *q = page_waitqueue(&folio->page); - wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_UNINTERRUPTIBLE, + folio_wait_bit_common(folio, PG_locked, TASK_UNINTERRUPTIBLE, EXCLUSIVE); } EXPORT_SYMBOL(__folio_lock); int __folio_lock_killable(struct folio *folio) { - wait_queue_head_t *q = page_waitqueue(&folio->page); - return wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_KILLABLE, + return folio_wait_bit_common(folio, PG_locked, TASK_KILLABLE, EXCLUSIVE); } EXPORT_SYMBOL_GPL(__folio_lock_killable); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 8e086f431690..7ad5538f2489 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2842,7 +2842,7 @@ void folio_wait_writeback(struct folio *folio) { while (folio_writeback(folio)) { trace_wait_on_page_writeback(&folio->page, folio_mapping(folio)); - wait_on_page_bit(&folio->page, PG_writeback); + folio_wait_bit(folio, PG_writeback); } } EXPORT_SYMBOL_GPL(folio_wait_writeback); @@ -2864,7 +2864,7 @@ int folio_wait_writeback_killable(struct folio *folio) { while (folio_writeback(folio)) { trace_wait_on_page_writeback(&folio->page, folio_mapping(folio)); - if (wait_on_page_bit_killable(&folio->page, PG_writeback)) + if (folio_wait_bit_killable(folio, PG_writeback)) return -EINTR; }