From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v6 48/99] shmem: Convert shmem_free_swap to XArray Date: Wed, 17 Jan 2018 12:21:12 -0800 Message-ID: <20180117202203.19756-49-willy@infradead.org> References: <20180117202203.19756-1-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=gAsKqAbzlPdEL8CQu2IbCd5XNLOOTFlIQ3rDu9U+74Q=; b=Pl0/nBJxXI9XeEdQNQNE08+iDE ofKATtoR7lE03zM/1sbJILIGt5rNGBy2iecYlrtblqlZPdMB4QqqHtxF+0xwyaHLfRwGb4H1s5qI/ gn366CuddO5eBtj2OwwQvD+pQZWOPCdevCIabCmZ+F93okZgrkczDcInAXP31Rnugnu4=; 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=gAsKqAbzlPdEL8CQu2IbCd5XNLOOTFlIQ3rDu9U+74Q=; b=klRQujDLZYKC4EwkYMcJ3bZPR3 lU35HpINc7Byh2FlmrmWdKirGwz6EoblK/35taTvp4h5dqoDNsNWx5ZpIbQAaAVDFmDu3NO9E6Hxx Gx2gKt4/YMxDgtxFCS+rqtWnk55q5oJnGZmQO49wpIs6qiNzIemjSIFAWKRmDhhBB11o=; 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=gAsKqAbzlPdEL8CQu2IbCd5XNLOOTFlIQ3rDu9U+74Q=; b=GMVfCuzZbBNVdg4JB06NfIgse 3UUPrU1E3TkrJhLbjAqrCJWJdkl2p8vgNQTnm8J4C4finQNDiFu+QR+kYr2Wec7IZwvXNk/FE76UH nZ7g/t5BFMcuzXQr2SVBhs2sIf3ZlIbb0N08diJC3WwPhwHvGX7qyWDkNGat9XlRoWW6g4fGuZfcr eFOf8pL2T1oa/0mEbjhNacmXS4dDKRZFAsjqEs+kfc/ALiW1GLeE/nB9AqvHr7qHdLWL4r4FoUhnJ JcnUFvygRly8pqXXFamAnSABcydXi6BeF4wcpA0i/ehCw/xZcQ2q40wqOlv0rWHoR5PLfHYxArEMm zC4jdo5gA==; In-Reply-To: <20180117202203.19756-1-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-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, David Howells , linux-nilfs@vger.kernel.org, Matthew Wilcox , linux-sh@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-usb@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Stefano Stabellini , linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, Bjorn Andersson , linux-btrfs@vger.kernel.org From: Matthew Wilcox This is a perfect use for xa_cmpxchg(). Note the use of 0 for GFP flags; we won't be allocating memory. Signed-off-by: Matthew Wilcox --- mm/shmem.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index e8233cb7ab5c..5a2226e06f8c 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -635,16 +635,13 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) } /* - * Remove swap entry from radix tree, free the swap and its page cache. + * Remove swap entry from page cache, free the swap and its page cache. */ static int shmem_free_swap(struct address_space *mapping, pgoff_t index, void *radswap) { - void *old; + void *old = xa_cmpxchg(&mapping->pages, index, radswap, NULL, 0); - xa_lock_irq(&mapping->pages); - old = radix_tree_delete_item(&mapping->pages, index, radswap); - xa_unlock_irq(&mapping->pages); if (old != radswap) return -ENOENT; free_swap_and_cache(radix_to_swp_entry(radswap)); -- 2.15.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot