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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 60B52C2D0AE for ; Tue, 13 Oct 2020 23:51:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DB9C721D81 for ; Tue, 13 Oct 2020 23:51:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rmOq18sL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB9C721D81 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8044B6B0089; Tue, 13 Oct 2020 19:51:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7B4AC6B0093; Tue, 13 Oct 2020 19:51:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6CB5D900002; Tue, 13 Oct 2020 19:51:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0034.hostedemail.com [216.40.44.34]) by kanga.kvack.org (Postfix) with ESMTP id 40EBF6B0089 for ; Tue, 13 Oct 2020 19:51:27 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D8FE73629 for ; Tue, 13 Oct 2020 23:51:26 +0000 (UTC) X-FDA: 77368551372.05.comb20_0f08e4027207 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id BF83A18016695 for ; Tue, 13 Oct 2020 23:51:26 +0000 (UTC) X-HE-Tag: comb20_0f08e4027207 X-Filterd-Recvd-Size: 3683 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 23:51:26 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 32E4D21D7A; Tue, 13 Oct 2020 23:51:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633085; bh=bX7VzBOzh53KeWxHAEHq2ingEbvqR0h7IECo0hgmsos=; h=Date:From:To:Subject:In-Reply-To:From; b=rmOq18sL0cdiwXH/LXHVJt6eS1o6gn3hfwfA/lmWGeC4syeGdzAxletgmIkidPaNX QpBXy+Nt26OjYY9ZHquXj20zQOCtO12Tc6klOFxzlwtkbclqFQ8pbYZhA0PoBXqBpW 2YjpaRER7DXcVYJlRVYN8o/VxEbt7EokLValB5vA= Date: Tue, 13 Oct 2020 16:51:24 -0700 From: Andrew Morton To: adobriyan@gmail.com, akpm@linux-foundation.org, cai@redhat.com, chris@chris-wilson.co.uk, hannes@cmpxchg.org, hughd@google.com, jani.nikula@linux.intel.com, linux-mm@kvack.org, matthew.auld@intel.com, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, william.kucharski@oracle.com, willy@infradead.org, ying.huang@intel.com Subject: [patch 056/181] mm: optimise madvise WILLNEED Message-ID: <20201013235124.9efI4nvew%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: "Matthew Wilcox (Oracle)" Subject: mm: optimise madvise WILLNEED Instead of calling find_get_entry() for every page index, use an XArray iterator to skip over NULL entries, and avoid calling get_page(), because we only want the swap entries. [willy@infradead.org: fix LTP soft lockups] Link: https://lkml.kernel.org/r/20200914165032.GS6583@casper.infradead.org Link: https://lkml.kernel.org/r/20200910183318.20139-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Johannes Weiner Cc: Alexey Dobriyan Cc: Chris Wilson Cc: Huang Ying Cc: Hugh Dickins Cc: Jani Nikula Cc: Matthew Auld Cc: William Kucharski Cc: Qian Cai Signed-off-by: Andrew Morton --- mm/madvise.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) --- a/mm/madvise.c~mm-optimise-madvise-willneed +++ a/mm/madvise.c @@ -224,25 +224,28 @@ static void force_shm_swapin_readahead(s unsigned long start, unsigned long end, struct address_space *mapping) { - pgoff_t index; + XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); + pgoff_t end_index = end / PAGE_SIZE; struct page *page; - swp_entry_t swap; - for (; start < end; start += PAGE_SIZE) { - index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; + rcu_read_lock(); + xas_for_each(&xas, page, end_index) { + swp_entry_t swap; - page = find_get_entry(mapping, index); - if (!xa_is_value(page)) { - if (page) - put_page(page); + if (!xa_is_value(page)) continue; - } + xas_pause(&xas); + rcu_read_unlock(); + swap = radix_to_swp_entry(page); page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, NULL, 0, false); if (page) put_page(page); + + rcu_read_lock(); } + rcu_read_unlock(); lru_add_drain(); /* Push any new pages onto the LRU now */ } _