linux-kernel - Re: [dm-devel] [PATCH] Fix I/O counts in vmstat

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]

Date:	Wed, 21 Mar 2012 19:04:08 +0900
From:	"Jun'ichi Nomura" <j-nomura@...jp.nec.com>
To:	device-mapper development <dm-devel@...hat.com>,
	Mikulas Patocka <mpatocka@...hat.com>
CC:	"Alasdair G. Kergon" <agk@...hat.com>,
	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org
Subject: Re: [dm-devel] [PATCH] Fix I/O counts in vmstat

Hi Mikulas,

> The decision whether bio is counted or not is made by the code that
> submits the bio. This leads to some problems:

How about convering dm targets to use generic_make_request?

Since submit_bio counts vm events, it seems natural for
caller to decide which function to use.
Device driver does not know whether the requested I/O is
for vm-to-device or device-to-device.
We could still use iostat to measure throughput of individual
block devices. 

Thanks,
-- 
Jun'ichi Nomura, NEC Corporation
--
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/