From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id ABF7D8D0039 for ; Tue, 22 Feb 2011 08:35:46 -0500 (EST) Date: Tue, 22 Feb 2011 14:35:20 +0100 From: Andrea Arcangeli Subject: Re: [PATCH 4/5] teach smaps_pte_range() about THP pmds Message-ID: <20110222133520.GS13092@random.random> References: <20110222015338.309727CA@kernel> <20110222015343.41586948@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110222015343.41586948@kernel> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michael J Wolf , akpm@osdl.org, Mel Gorman , Johannes Weiner On Mon, Feb 21, 2011 at 05:53:43PM -0800, Dave Hansen wrote: > @@ -385,8 +387,25 @@ static int smaps_pte_range(pmd_t *pmd, u > pte_t *pte; > spinlock_t *ptl; > > - split_huge_page_pmd(walk->mm, pmd); > - > + spin_lock(&walk->mm->page_table_lock); > + if (pmd_trans_huge(*pmd)) { > + if (pmd_trans_splitting(*pmd)) { > + spin_unlock(&walk->mm->page_table_lock); > + wait_split_huge_page(vma->anon_vma, pmd); > + } else { > + smaps_pte_entry(*(pte_t *)pmd, addr, > + HPAGE_PMD_SIZE, walk); > + spin_unlock(&walk->mm->page_table_lock); > + return 0; > + } > + } else { > + spin_unlock(&walk->mm->page_table_lock); > + } > + /* > + * The mmap_sem held all the way back in m_start() is what > + * keeps khugepaged out of here and from collapsing things > + * in here. > + */ This time the locking is right and HPAGE_PMD_SIZE is used instead of HPAGE_SIZE, thanks! I think all 5 patches can go in -mm and upstream anytime (not mandatory for 2.6.38 but definitely we want this for 2.6.39). BTW, Andi in his NUMA THP improvement series added a THP_SPLIT vmstat per-cpu counter so that part removed from his series, is taken care by him. Acked-by: Andrea Arcangeli -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org