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=-12.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 55999C43461 for ; Mon, 14 Sep 2020 13:01:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F3571206B2 for ; Mon, 14 Sep 2020 13:01:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gDn66Rgt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3571206B2 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 DAA66900007; Mon, 14 Sep 2020 09:01:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D5817900004; Mon, 14 Sep 2020 09:01:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C22CF900007; Mon, 14 Sep 2020 09:01:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id A2A99900004 for ; Mon, 14 Sep 2020 09:01:09 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0CD3B363B for ; Mon, 14 Sep 2020 13:01:09 +0000 (UTC) X-FDA: 77261677458.15.lead97_1c09b6027108 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 5D997180199CD for ; Mon, 14 Sep 2020 13:01:00 +0000 (UTC) X-HE-Tag: lead97_1c09b6027108 X-Filterd-Recvd-Size: 6425 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Mon, 14 Sep 2020 13:00:59 +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=EHgzdRosBMsz0w0GEEdwo/W7ei2Jp7MgX6g3BY09CJk=; b=gDn66RgtJXXmxOQbT+bHpRicPg QRqGFAlitj5356PJyc2I/jZtYMdlOl5H0SZ+QgfNlzqtRSKr7WmwCx71OAgBP7AyW2Urvi2EuSWJl pqRXY5QxeF9sHBXEu8CybYYVGJ6L+ly6sSEz9w1t5aR7/zGkyLHvv4XRAxdKulMEqYxSezQBfahD5 hgQKwQpB3Bc426SoBubGjDftU5Qwjau0qPy/5V+dGTS4TAZB2Vnwc/T69ei3uBRZqPuioJ7fiN+4t pysdnw4fBtaxKOaKz0D5+4roBgqXqOR+D95NhFXMT2xMD83P69s5A+cG1dNtjiFDYdt/4OzjR13XF QP4v67MQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHo68-0002zr-Th; Mon, 14 Sep 2020 13:00:44 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , Andrew Morton , Hugh Dickins , William Kucharski , Johannes Weiner , Jan Kara , Yang Shi , Dave Chinner , linux-kernel@vger.kernel.org Subject: [PATCH v2 03/12] mm/filemap: Add helper for finding pages Date: Mon, 14 Sep 2020 14:00:33 +0100 Message-Id: <20200914130042.11442-4-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200914130042.11442-1-willy@infradead.org> References: <20200914130042.11442-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: 5D997180199CD X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 Content-Transfer-Encoding: quoted-printable 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: There is a lot of common code in find_get_entries(), find_get_pages_range() and find_get_pages_range_tag(). Factor out xas_find_get_entry() which simplifies all three functions. Signed-off-by: Matthew Wilcox (Oracle) --- mm/filemap.c | 98 +++++++++++++++++++++++----------------------------- 1 file changed, 43 insertions(+), 55 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 7d8cf1a25628..d8f5ff07eb9c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1758,6 +1758,43 @@ struct page *pagecache_get_page(struct address_spa= ce *mapping, pgoff_t index, } EXPORT_SYMBOL(pagecache_get_page); =20 +static inline struct page *xas_find_get_entry(struct xa_state *xas, + pgoff_t max, xa_mark_t mark) +{ + struct page *page; + +retry: + if (mark =3D=3D XA_PRESENT) + page =3D xas_find(xas, max); + else + page =3D xas_find_marked(xas, max, mark); + + if (xas_retry(xas, page)) + goto retry; + /* + * A shadow entry of a recently evicted page, a swap + * entry from shmem/tmpfs or a DAX entry. Return it + * without attempting to raise page count. + */ + if (!page || xa_is_value(page)) + return page; + + if (!page_cache_get_speculative(page)) + goto reset; + + /* Has the page moved or been split? */ + if (unlikely(page !=3D xas_reload(xas))) { + put_page(page); + goto reset; + } + VM_BUG_ON_PAGE(!thp_contains(page, xas->xa_index), page); + + return page; +reset: + xas_reset(xas); + goto retry; +} + /** * find_get_entries - gang pagecache lookup * @mapping: The address_space to search @@ -1797,42 +1834,21 @@ unsigned find_get_entries(struct address_space *m= apping, return 0; =20 rcu_read_lock(); - xas_for_each(&xas, page, ULONG_MAX) { - if (xas_retry(&xas, page)) - continue; - /* - * A shadow entry of a recently evicted page, a swap - * entry from shmem/tmpfs or a DAX entry. Return it - * without attempting to raise page count. - */ - if (xa_is_value(page)) - goto export; - - if (!page_cache_get_speculative(page)) - goto retry; - - /* Has the page moved or been split? */ - if (unlikely(page !=3D xas_reload(&xas))) - goto put_page; - + while ((page =3D xas_find_get_entry(&xas, ULONG_MAX, XA_PRESENT))) { /* * Terminate early on finding a THP, to allow the caller to * handle it all at once; but continue if this is hugetlbfs. */ - if (PageTransHuge(page) && !PageHuge(page)) { + if (!xa_is_value(page) && PageTransHuge(page) && + !PageHuge(page)) { page =3D find_subpage(page, xas.xa_index); nr_entries =3D ret + 1; } -export: + indices[ret] =3D xas.xa_index; entries[ret] =3D page; if (++ret =3D=3D nr_entries) break; - continue; -put_page: - put_page(page); -retry: - xas_reset(&xas); } rcu_read_unlock(); return ret; @@ -1871,30 +1887,16 @@ unsigned find_get_pages_range(struct address_spac= e *mapping, pgoff_t *start, return 0; =20 rcu_read_lock(); - xas_for_each(&xas, page, end) { - if (xas_retry(&xas, page)) - continue; + while ((page =3D xas_find_get_entry(&xas, end, XA_PRESENT))) { /* Skip over shadow, swap and DAX entries */ if (xa_is_value(page)) continue; =20 - if (!page_cache_get_speculative(page)) - goto retry; - - /* Has the page moved or been split? */ - if (unlikely(page !=3D xas_reload(&xas))) - goto put_page; - pages[ret] =3D find_subpage(page, xas.xa_index); if (++ret =3D=3D nr_pages) { *start =3D xas.xa_index + 1; goto out; } - continue; -put_page: - put_page(page); -retry: - xas_reset(&xas); } =20 /* @@ -1993,9 +1995,7 @@ unsigned find_get_pages_range_tag(struct address_sp= ace *mapping, pgoff_t *index, return 0; =20 rcu_read_lock(); - xas_for_each_marked(&xas, page, end, tag) { - if (xas_retry(&xas, page)) - continue; + while ((page =3D xas_find_get_entry(&xas, end, tag))) { /* * Shadow entries should never be tagged, but this iteration * is lockless so there is a window for page reclaim to evict @@ -2004,23 +2004,11 @@ unsigned find_get_pages_range_tag(struct address_= space *mapping, pgoff_t *index, if (xa_is_value(page)) continue; =20 - if (!page_cache_get_speculative(page)) - goto retry; - - /* Has the page moved or been split? */ - if (unlikely(page !=3D xas_reload(&xas))) - goto put_page; - pages[ret] =3D page; if (++ret =3D=3D nr_pages) { *index =3D page->index + thp_nr_pages(page); goto out; } - continue; -put_page: - put_page(page); -retry: - xas_reset(&xas); } =20 /* --=20 2.28.0