From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id A66956B004A for ; Wed, 22 Sep 2010 04:40:50 -0400 (EDT) Date: Wed, 22 Sep 2010 09:40:35 +0100 From: Mel Gorman Subject: Re: [PATCH 04/10] hugetlb: hugepage migration core Message-ID: <20100922084035.GC1382@csn.ul.ie> References: <1283908781-13810-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1283908781-13810-5-git-send-email-n-horiguchi@ah.jp.nec.com> <20100920111054.GJ1998@csn.ul.ie> <20100922045907.GC2538@spritzera.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100922045907.GC2538@spritzera.linux.bs1.fc.nec.co.jp> Sender: owner-linux-mm@kvack.org To: Naoya Horiguchi Cc: Andi Kleen , Andrew Morton , Christoph Lameter , Wu Fengguang , Jun'ichi Nomura , linux-mm , LKML List-ID: On Wed, Sep 22, 2010 at 01:59:07PM +0900, Naoya Horiguchi wrote: > On Mon, Sep 20, 2010 at 12:10:55PM +0100, Mel Gorman wrote: > > On Wed, Sep 08, 2010 at 10:19:35AM +0900, Naoya Horiguchi wrote: > ... > > > @@ -95,26 +96,34 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, > > > pte_t *ptep, pte; > > > spinlock_t *ptl; > > > > > > - pgd = pgd_offset(mm, addr); > > > - if (!pgd_present(*pgd)) > > > - goto out; > > > + if (unlikely(PageHuge(new))) { > > > + ptep = huge_pte_offset(mm, addr); > > > + if (!ptep) > > > + goto out; > > > + ptl = &mm->page_table_lock; > > > + } else { > > > + pgd = pgd_offset(mm, addr); > > > + if (!pgd_present(*pgd)) > > > + goto out; > > > > > > - pud = pud_offset(pgd, addr); > > > - if (!pud_present(*pud)) > > > - goto out; > > > + pud = pud_offset(pgd, addr); > > > + if (!pud_present(*pud)) > > > + goto out; > > > > > > > Why are the changes to teh rest of the walkers necessary? Instead, why > > did you not identify which PTL lock you needed and then goto the point > > where spin_lock(ptl) is called? Similar to what page_check_address() > > does for example. > > This is because Andi-san commented to avoid using goto sentense. > But honestly I'm not sure which is a clear way. > Ok, personally I would prefer to have matched page_check_address() so we use similar code patterns when the intention is the same but as functionally it seems fine, I'm not going to fight over it either. Thanks. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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