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: <201008300242.27331.hka@qbs.com.pl>
Date:	Mon, 30 Aug 2010 02:42:26 +0200
From:	Hubert Kario <hka@....com.pl>
To:	Shaohua Li <shaohua.li@...el.com>
Cc:	"bchociej@...il.com" <bchociej@...il.com>,
	"chris.mason@...cle.com" <chris.mason@...cle.com>,
	"linux-btrfs@...r.kernel.org" <linux-btrfs@...r.kernel.org>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"cmm@...ibm.com" <cmm@...ibm.com>,
	"bcchocie@...ibm.com" <bcchocie@...ibm.com>,
	"mrlupfer@...ibm.com" <mrlupfer@...ibm.com>,
	"crscott@...ibm.com" <crscott@...ibm.com>,
	"mlupfer@...il.com" <mlupfer@...il.com>,
	"conscott@...edu" <conscott@...edu>
Subject: Re: [RFC v2 PATCH 0/6] Btrfs: Add hot data relocation functionality

On Thursday 26 of August 2010 04:13:43 Shaohua Li wrote:
> On Fri, Aug 13, 2010 at 06:22:00AM +0800, bchociej@...il.com wrote:
> > - Hooks in existing Btrfs functions to track data access frequency
> > 
> >   (btrfs_direct_IO, btrfs_readpages, and extent_write_cache_pages)
> > 
> > - New rbtrees for tracking access frequency of inodes and sub-file
> > 
> >   ranges (hotdata_map.c)
> > 
> > - A hash list for indexing data by its temperature (hotdata_hash.c)
> > 
> > - A debugfs interface for dumping data from the rbtrees (debugfs.c)
> > 
> > - A background kthread for relocating data to faster media based on
> > 
> >   temperature
> 
> Hi,
> I'm wondering if the temperature info can be exported to userspace, and
> let a daemon to do the relocation (by ioctl). A userspace daemon is more
> flexible.

Flexibility of userspace daemon is one thing, the ability to let the admin 
precisely control on which drive data is placed could be really beneficial in 
some scenarios is another thing.

This would also allow online defragmentation, together with access to 
statistics, one that (for quick runs) has really good time/performance benefit 
ratio.
-- 
Hubert Kario
QBS - Quality Business Software
02-656 Warszawa, ul. Ksawerów 30/85
tel. +48 (22) 646-61-51, 646-74-24
www.qbs.com.pl
--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ