linux-kernel - Re: [PATCH v2] After swapout/swapin private dirty mappings are reported clean in smaps

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20100915134724.C9EE.A69D9226@jp.fujitsu.com>
Date:	Wed, 15 Sep 2010 13:48:11 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Nikanth Karthikesan <knikanth@...e.de>
Cc:	kosaki.motohiro@...fujitsu.com,
	Richard Guenther <rguenther@...e.de>, linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	balbir@...ux.vnet.ibm.com, Michael Matz <matz@...ell.com>,
	Matt Mackall <mpm@...enic.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] After swapout/swapin private dirty mappings are reported clean in smaps

> On Wednesday 15 September 2010 05:56:36 KOSAKI Motohiro wrote:
> > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> > > index 439fc1f..06fc468 100644
> > > --- a/fs/proc/task_mmu.c
> > > +++ b/fs/proc/task_mmu.c
> > > @@ -368,7 +368,11 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long
> > > addr, unsigned long end, mss->shared_clean += PAGE_SIZE;
> > >  			mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount;
> > >  		} else {
> > > -			if (pte_dirty(ptent))
> > > +			/*
> > > +			 * File-backed pages, now anonymous are dirty
> > > +			 * with respect to the file.
> > > +			 */
> > > +			if (pte_dirty(ptent) || (vma->vm_file && PageAnon(page)))
> > >  				mss->private_dirty += PAGE_SIZE;
> > >  			else
> > >  				mss->private_clean += PAGE_SIZE;
> > 
> > This is risky than v1. number of dirties are used a lot of application.
> > 
> 
> This is exactly to help those applications, as currently after swap-out and 
> swap-in, the same pages are accounted as "Private_Clean:" instead of 
> "Private_Dirty:".

I don't think so. incorrect infomation bring a lot of confusion rather than its worth.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/