From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757974Ab2AMLuR (ORCPT ); Fri, 13 Jan 2012 06:50:17 -0500 Received: from e23smtp03.au.ibm.com ([202.81.31.145]:56949 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751683Ab2AMLuH (ORCPT ); Fri, 13 Jan 2012 06:50:07 -0500 Message-ID: <4F1019D3.8020709@linux.vnet.ibm.com> Date: Fri, 13 Jan 2012 19:47:31 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: Xiao Guangrong CC: Andrew Morton , William Irwin , linux-mm@kvack.org, LKML Subject: [PATCH 5/5] mm: search from free_area_cache for the bigger size References: <4F101904.8090405@linux.vnet.ibm.com> In-Reply-To: <4F101904.8090405@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12011301-6102-0000-0000-000000A22831 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the required size is bigger than cached_hole_size, we would better search from free_area_cache, it is more easier to get free region, specifically for the 64 bit process whose address space is large enough Do it just as hugetlb_get_unmapped_area_topdown() in arch/x86/mm/hugetlbpage.c Signed-off-by: Xiao Guangrong --- arch/x86/kernel/sys_x86_64.c | 34 +++++++++++++++++----------------- mm/mmap.c | 36 +++++++++++++++++++++--------------- 2 files changed, 38 insertions(+), 32 deletions(-) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index 0514890..ef59642 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -195,7 +195,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, { struct vm_area_struct *vma; struct mm_struct *mm = current->mm; - unsigned long addr = addr0; + unsigned long addr = addr0, start_addr; /* requested length too big for entire address space */ if (len > TASK_SIZE) @@ -223,25 +223,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, mm->free_area_cache = mm->mmap_base; } +try_again: /* either no address requested or can't fit in requested address hole */ - addr = mm->free_area_cache; - - /* make sure it can fit in the remaining address space */ - if (addr > len) { - unsigned long tmp_addr = align_addr(addr - len, filp, - ALIGN_TOPDOWN); - - vma = find_vma(mm, tmp_addr); - if (!vma || tmp_addr + len <= vma->vm_start) - /* remember the address as a hint for next time */ - return mm->free_area_cache = tmp_addr; - } - - if (mm->mmap_base < len) - goto bottomup; + start_addr = addr = mm->free_area_cache; - addr = mm->mmap_base-len; + if (addr < len) + goto fail; + addr -= len; do { addr = align_addr(addr, filp, ALIGN_TOPDOWN); @@ -263,6 +252,17 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, addr = vma->vm_start-len; } while (len < vma->vm_start); +fail: + /* + * if hint left us with no space for the requested + * mapping then try again: + */ + if (start_addr != mm->mmap_base) { + mm->free_area_cache = mm->mmap_base; + mm->cached_hole_size = 0; + goto try_again; + } + bottomup: /* * A failed mmap() very likely causes application failure, diff --git a/mm/mmap.c b/mm/mmap.c index 970f572..e3c4b97 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1439,7 +1439,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, { struct vm_area_struct *vma; struct mm_struct *mm = current->mm; - unsigned long addr = addr0; + unsigned long addr = addr0, start_addr; /* requested length too big for entire address space */ if (len > TASK_SIZE) @@ -1463,22 +1463,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, mm->free_area_cache = mm->mmap_base; } +try_again: /* either no address requested or can't fit in requested address hole */ - addr = mm->free_area_cache; + start_addr = addr = mm->free_area_cache; - /* make sure it can fit in the remaining address space */ - if (addr > len) { - vma = find_vma(mm, addr-len); - if (!vma || addr <= vma->vm_start) - /* remember the address as a hint for next time */ - return (mm->free_area_cache = addr-len); - } - - if (mm->mmap_base < len) - goto bottomup; - - addr = mm->mmap_base-len; + if (addr < len) + goto fail; + addr -= len; do { /* * Lookup failure means no vma is above this address, @@ -1498,7 +1490,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, addr = vma->vm_start-len; } while (len < vma->vm_start); -bottomup: +fail: + /* + * if hint left us with no space for the requested + * mapping then try again: + * + * Note: this is different with the case of bottomup + * which does the fully line-search, but we use find_vma + * here that causes some holes skipped. + */ + if (start_addr != mm->mmap_base) { + mm->free_area_cache = mm->mmap_base; + mm->cached_hole_size = 0; + goto try_again; + } + /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario -- 1.7.7.5