From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: linux-next: manual merge of the akpm tree with Linus' tree Date: Thu, 08 Mar 2012 17:59:02 +0800 Message-ID: <4F5882E6.8080202@linux.vnet.ibm.com> References: <20120308175307.b295b1013728a5666fe4571a@canb.auug.org.au> <20120307233220.5a76aa3c.akpm@linux-foundation.org> <20120308184105.5b03ec90bcddf90562181277@canb.auug.org.au> <20120307235012.847af577.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from e23smtp08.au.ibm.com ([202.81.31.141]:39533 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751644Ab2CHJ7U (ORCPT ); Thu, 8 Mar 2012 04:59:20 -0500 Received: from /spool/local by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 8 Mar 2012 09:56:56 +1000 In-Reply-To: <20120307235012.847af577.akpm@linux-foundation.org> Sender: linux-next-owner@vger.kernel.org List-ID: To: Andrew Morton Cc: Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Linus On 03/08/2012 03:50 PM, Andrew Morton wrote: > Doh. The author reviewed that for me too! > > I'll drop it - please rework, retest and resend? > Andrew, the patch has been reworked. Subject: [PATCH] hugetlb: drop prev_vma in hugetlb_get_unmapped_area_topdown() After the call find_vma_prev(mm, addr, &prev_vma), the following condition is always true: !prev_vma || (addr >= prev_vma->vm_end) it can happily drop prev_vma and use find_vma() instead of find_vma_prev(). Signed-off-by: Xiao Guangrong --- arch/x86/mm/hugetlbpage.c | 18 +++++------------- 1 files changed, 5 insertions(+), 13 deletions(-) diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 8ecbb4b..0c1701b 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -308,7 +308,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, { struct hstate *h = hstate_file(file); struct mm_struct *mm = current->mm; - struct vm_area_struct *vma, *prev_vma; + struct vm_area_struct *vma; unsigned long base = mm->mmap_base, addr = addr0; unsigned long largest_hole = mm->cached_hole_size; int first_time = 1; @@ -337,22 +337,14 @@ try_again: if (!vma) return addr; - /* - * new region fits between prev_vma->vm_end and - * vma->vm_start, use it: - */ - prev_vma = vma->vm_prev; - if (addr + len <= vma->vm_start && - (!prev_vma || (addr >= prev_vma->vm_end))) { + if (addr + len <= vma->vm_start) { /* remember the address as a hint for next time */ mm->cached_hole_size = largest_hole; return (mm->free_area_cache = addr); - } else { + } else if (mm->free_area_cache == vma->vm_end) { /* pull free_area_cache down to the first hole */ - if (mm->free_area_cache == vma->vm_end) { - mm->free_area_cache = vma->vm_start; - mm->cached_hole_size = largest_hole; - } + mm->free_area_cache = vma->vm_start; + mm->cached_hole_size = largest_hole; } /* remember the largest hole we saw so far */ -- 1.7.7.6