Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756495AbbKDXku (ORCPT <rfc822;w@1wt.eu>);
	Wed, 4 Nov 2015 18:40:50 -0500
Received: from LGEAMRELO11.lge.com ([156.147.23.51]:44682 "EHLO
	lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756229AbbKDXks (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 4 Nov 2015 18:40:48 -0500
X-Original-SENDERIP: 156.147.1.151
X-Original-MAILFROM: minchan@kernel.org
X-Original-SENDERIP: 165.244.98.150
X-Original-MAILFROM: minchan@kernel.org
X-Original-SENDERIP: 10.177.223.161
X-Original-MAILFROM: minchan@kernel.org
Date: Thu, 5 Nov 2015 08:40:55 +0900
From: Minchan Kim <minchan@kernel.org>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Michael Kerrisk <mtk.manpages@gmail.com>,
        linux-api@vger.kernel.org, Hugh Dickins <hughd@google.com>,
        Johannes Weiner <hannes@cmpxchg.org>, Rik van Riel <riel@redhat.com>,
        Mel Gorman <mgorman@suse.de>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Jason Evans <je@fb.com>, Daniel Micay <danielmicay@gmail.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Shaohua Li <shli@kernel.org>, Michal Hocko <mhocko@suse.cz>,
        yalin.wang2010@gmail.com
Subject: Re: [PATCH v2 01/13] mm: support madvise(MADV_FREE)
Message-ID: <20151104234055.GB7357@bbox>
References: <1446600367-7976-1-git-send-email-minchan@kernel.org>
 <1446600367-7976-2-git-send-email-minchan@kernel.org>
 <20151104022951.GA3744@swordfish>
MIME-Version: 1.0
In-Reply-To: <20151104022951.GA3744@swordfish>
User-Agent: Mutt/1.5.21 (2010-09-15)
X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB07/LGE/LG Group(Release 8.5.3FP6|November
 21, 2013) at 2015/11/05 08:40:45,
	Serialize by Router on LGEKRMHUB07/LGE/LG Group(Release 8.5.3FP6|November
 21, 2013) at 2015/11/05 08:40:45,
	Serialize complete at 2015/11/05 08:40:45
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1481
Lines: 51

On Wed, Nov 04, 2015 at 11:29:51AM +0900, Sergey Senozhatsky wrote:
> On (11/04/15 10:25), Minchan Kim wrote:
> [..]
> > +static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
> > +				unsigned long end, struct mm_walk *walk)
> > +
> > +{
> > +	struct mmu_gather *tlb = walk->private;
> > +	struct mm_struct *mm = tlb->mm;
> > +	struct vm_area_struct *vma = walk->vma;
> > +	spinlock_t *ptl;
> > +	pte_t *pte, ptent;
> > +	struct page *page;
> 
> 
> I'll just ask (probably I'm missing something)
> 
> 	+ pmd_trans_huge_lock() ?

No. It would be deadlock.

> 
> > +	split_huge_page_pmd(vma, addr, pmd);
> > +	if (pmd_trans_unstable(pmd))
> > +		return 0;
> > +
> > +	pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
> > +	arch_enter_lazy_mmu_mode();
> > +	for (; addr != end; pte++, addr += PAGE_SIZE) {
> > +		ptent = *pte;
> > +
> > +		if (!pte_present(ptent))
> > +			continue;
> > +
> > +		page = vm_normal_page(vma, addr, ptent);
> > +		if (!page)
> > +			continue;
> > +
> 
> 	-ss
> 
> --
> 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/