From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v14 55/74] memfd: Convert memfd_tag_pins to XArray Date: Sat, 16 Jun 2018 19:00:33 -0700 Message-ID: <20180617020052.4759-56-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=3dt1i9NP1EXxETQ4D4nD6mkkx/fkw3evvLQHvoVxbqY=; b=DwwbmQW0tZu8puYABi46FVgf35 7ledf0KYwGrt9fO6gUMOfVJioK2T+MFlSRhfS8HGuj864SxNCwxAQ/FdEGrRoJUTPLbfSaWcL8sVH y7ymdWlGxOcZiUpI5nvTztxIXYsPfZ7RlDYd1LDCnGxeeNSOpxtX10A4dSaVYHEYhE9U=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To :MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=3dt1i9NP1EXxETQ4D4nD6mkkx/fkw3evvLQHvoVxbqY=; b=NCwXwa/4sipcA0ra0WZ8ePcVLR E/EQJK4IYcRmm20LceHeDJaCJlj17m8YWRIt9mH7JESrihJo8atq3M5x6iTv7SV011l8QTfTDuy4I 0QFFN44vJOqJfMW0eTWOAeDOV9Ti1L4kTCvgxbeg6DNhCGU6v2HzqhmtBjrwXvMbZQxo=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=3dt1i9NP1EXxETQ4D4nD6mkkx/fkw3evvLQHvoVxbqY=; b=hBhoTythSko0pFY65cmmmSvgH k2HXrqUZ3It06bxZLbP7ijoSrRGWitmutjXTJjSfEIh/TXudmVVJCox6fMusITIZRrLbt0BM/toUB wQV2ThXABL0BEAUAZxy4SKjGCeKLU/M4k9EBHd1u+G7r0ud03kQYqSAniHfKkfsmx9rfQxWhJ3PVW ZfYMttSmUwDZWba0W5tMCQU7tkUNyFbjSmDt3fHI8Ah9GJaEqt9wuHSBUynvZVteNowLlgFFZ/IGA lVwubIOV2QQ3nwZu0pXN/riLYUln9uL77TLx7Kd9ODbWvQrW2Q2lk8l6zqGAmtgo2zT1pfO65DeHC rIr54DZvg==; In-Reply-To: <20180617020052.4759-1-willy@infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-nilfs@vger.kernel.org, Jan Kara , Jeff Layton , Jaegeuk Kim , Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, Nicholas Piggin , Ryusuke Konishi , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues Switch to a batch-processing model like memfd_wait_for_pins() and use the xa_state previously set up by memfd_wait_for_pins(). Signed-off-by: Matthew Wilcox Reviewed-by: Mike Kravetz --- mm/memfd.c | 44 ++++++++++++++++++-------------------------- 1 file changed, 18 insertions(+), 26 deletions(-) diff --git a/mm/memfd.c b/mm/memfd.c index e7d6be725b7a..636de8d5c7c3 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -28,37 +28,29 @@ #define MEMFD_TAG_PINNED PAGECACHE_TAG_TOWRITE #define LAST_SCAN 4 /* about 150ms max */ -static void memfd_tag_pins(struct address_space *mapping) +static void memfd_tag_pins(struct xa_state *xas) { - struct radix_tree_iter iter; - void __rcu **slot; - pgoff_t start; struct page *page; + unsigned int tagged = 0; lru_add_drain(); - start = 0; - rcu_read_lock(); - - radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) { - page = radix_tree_deref_slot(slot); - if (!page || radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - } else if (page_count(page) - page_mapcount(page) > 1) { - xa_lock_irq(&mapping->i_pages); - radix_tree_tag_set(&mapping->i_pages, iter.index, - MEMFD_TAG_PINNED); - xa_unlock_irq(&mapping->i_pages); - } - if (need_resched()) { - slot = radix_tree_iter_resume(slot, &iter); - cond_resched_rcu(); - } + xas_lock_irq(xas); + xas_for_each(xas, page, ULONG_MAX) { + if (xa_is_value(page)) + continue; + if (page_count(page) - page_mapcount(page) > 1) + xas_set_tag(xas, MEMFD_TAG_PINNED); + + if (++tagged % XA_CHECK_SCHED) + continue; + + xas_pause(xas); + xas_unlock_irq(xas); + cond_resched(); + xas_lock_irq(xas); } - rcu_read_unlock(); + xas_unlock_irq(xas); } /* @@ -76,7 +68,7 @@ static int memfd_wait_for_pins(struct address_space *mapping) struct page *page; int error, scan; - memfd_tag_pins(mapping); + memfd_tag_pins(&xas); error = 0; for (scan = 0; scan <= LAST_SCAN; scan++) { -- 2.17.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot