From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx175.postini.com [74.125.245.175]) by kanga.kvack.org (Postfix) with SMTP id 230706B0033 for ; Tue, 6 Aug 2013 04:43:43 -0400 (EDT) From: Joonsoo Kim Subject: [PATCH 2/4] mm, rmap: allocate anon_vma_chain before starting to link anon_vma_chain Date: Tue, 6 Aug 2013 17:43:38 +0900 Message-Id: <1375778620-31593-2-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <1375778620-31593-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1375778620-31593-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Minchan Kim , Johannes Weiner , Mel Gorman , Rik van Riel , Michel Lespinasse , Joonsoo Kim If we allocate anon_vma_chain before starting to link, we can reduce the lock hold time. This patch implement it. Signed-off-by: Joonsoo Kim diff --git a/mm/rmap.c b/mm/rmap.c index c2f51cb..1603f64 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -240,18 +240,21 @@ int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src) { struct anon_vma_chain *avc, *pavc; struct anon_vma *root = NULL; + LIST_HEAD(avc_list); + + list_for_each_entry(pavc, &src->anon_vma_chain, same_vma) { + avc = anon_vma_chain_alloc(GFP_KERNEL); + if (unlikely(!avc)) + goto enomem_failure; + + list_add_tail(&avc->same_vma, &avc_list); + } list_for_each_entry_reverse(pavc, &src->anon_vma_chain, same_vma) { struct anon_vma *anon_vma; - avc = anon_vma_chain_alloc(GFP_NOWAIT | __GFP_NOWARN); - if (unlikely(!avc)) { - unlock_anon_vma_root(root); - root = NULL; - avc = anon_vma_chain_alloc(GFP_KERNEL); - if (!avc) - goto enomem_failure; - } + avc = list_entry((&avc_list)->next, typeof(*avc), same_vma); + list_del(&avc->same_vma); anon_vma = pavc->anon_vma; root = lock_anon_vma_root(root, anon_vma); anon_vma_chain_link(dst, avc, anon_vma); @@ -259,8 +262,11 @@ int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src) unlock_anon_vma_root(root); return 0; - enomem_failure: - unlink_anon_vmas(dst); +enomem_failure: + list_for_each_entry_safe(avc, pavc, &avc_list, same_vma) { + list_del(&avc->same_vma); + anon_vma_chain_free(avc); + } return -ENOMEM; } -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org