From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Matthew Wilcox (Oracle)" Subject: [PATCH v2 3/8] mm: Optimise madvise WILLNEED Date: Thu, 10 Sep 2020 19:33:13 +0100 Message-ID: <20200910183318.20139-4-willy@infradead.org> References: <20200910183318.20139-1-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=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=5pz6pk0hQVCAmUCzXhhMl6SI7ek8eXmhvDqxhMsMWZA=; b=Z0ig8BZOOs874Iqk+s8Hjq2poV GfUU0UHAUN9Q10UU2Qc227BQGYSAuBuImaK2JLeoDFbGlpRzkAAOn6+/YaptLDl2FRANNaxYmEE3w mM4+ZjVmKwqOk3NY3DlezWO3uDRW1yESEcjvvUwqea0D+xOlNL846Qr76zhGuKKjx9HOj3KgtZscS jit7EaGeKPNdD6jg3LNu0n3gynAd6wlhzi9Hsj3R5Mi0n4mt1NX4STEfYrPFDWo1mhNjNsHg18nlj vZc8Lz/HCP7Iav4W1Li83NNG/RE38e7EQqq6JJ3V+y6qbzdR40ePerF8p7gTuN16/gueZ/fX6Ngp1 qzZoxrDw==; In-Reply-To: <20200910183318.20139-1-willy@infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: linux-mm@kvack.org Cc: intel-gfx@lists.freedesktop.org, Huang Ying , Hugh Dickins , linux-kernel@vger.kernel.org, Chris Wilson , William Kucharski , "Matthew Wilcox (Oracle)" , Johannes Weiner , cgroups@vger.kernel.org, Andrew Morton , Alexey Dobriyan , Matthew Auld 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. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Johannes Weiner --- mm/madvise.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index dd1d43cf026d..96189acd6969 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -224,25 +224,28 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma, 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; - } + 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(); + xas_reset(&xas); } + rcu_read_unlock(); lru_add_drain(); /* Push any new pages onto the LRU now */ } -- 2.28.0