linux-kernel - Re: [PATCH 5/5] blktrace: print human-readable act

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:	Tue, 24 Mar 2009 17:01:26 +0800
From:	Li Zefan <lizf@...fujitsu.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Jens Axboe <jens.axboe@...cle.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 5/5] blktrace: print human-readable act_mask

Ingo Molnar wrote:
> * Li Zefan <lizf@...fujitsu.com> wrote:
> 
>> Print stringified act_mask instead of hex value:
>>  # cat act_mask
>>  read,write,barrier,sync,queue,requeue,issue,complete,fs,pc,ahead,meta,
>>  discard,drv_data
>>  # echo "meta,write" > act_mask
>>  # cat act_mask
>>  write,meta
> 
> Nice!
> 
> It would also be nice to activate trace filters for the blktrace 
> tracepoints - i.e. to convert them to the TRACE_EVENT() enumeration 
> format. Beyond user-space parseable field enumeration and filter, 
> that will also speed up tracing and allows binary record streaming 
> with splice() zero-copy.
> 
> Via that "act_mask" can become a filterable field and you can define 
> expressions to filter. All other fields like sector become in-kernel 
> filterable too.
> 
> See a few examples here:
> 
>  include/trace/irq_event_types.h
>  include/trace/sched_event_types.h
> 
> Note, blktrace tracepoints are certainly more complex than the 
> tracepoints above - you can embedd C statements in TRACE_EVENT()'s 
> TP_fast_assign() bit.
> 
> It was specifically designed to allow the support of blktrace 
> tracepoints, so you can embedd the blk_pc_request() and disk_devt() 
> translation for the block_rq_complete event or 
> block_rq_requeue/issue tracepoints.
> 

I'll look into this when I have time. :)
--
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/