From: Avri Altman <Avri.Altman@wdc.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Bean Huo <huobean@gmail.com>,
"alim.akhtar@samsung.com" <alim.akhtar@samsung.com>,
"asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
"jejb@linux.ibm.com" <jejb@linux.ibm.com>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"stanley.chu@mediatek.com" <stanley.chu@mediatek.com>,
"beanhuo@micron.com" <beanhuo@micron.com>,
"bvanassche@acm.org" <bvanassche@acm.org>,
"tomas.winkler@intel.com" <tomas.winkler@intel.com>,
"cang@codeaurora.org" <cang@codeaurora.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v1 3/3] scsi: ufs: Make UPIU trace easier differentiate among CDB, OSF, and TM
Date: Tue, 8 Dec 2020 08:03:48 +0000 [thread overview]
Message-ID: <DM6PR04MB6575864DCED7720950302244FCCD0@DM6PR04MB6575.namprd04.prod.outlook.com> (raw)
In-Reply-To: <20201207122703.0190adf9@gandalf.local.home>
>
> On Mon, 7 Dec 2020 16:40:51 +0000
> Avri Altman <Avri.Altman@wdc.com> wrote:
>
> > >
> > > On Mon, 7 Dec 2020 07:57:27 +0000
> > > Avri Altman <Avri.Altman@wdc.com> wrote:
> > >
> > > > >
> > > > > TP_printk(
> > > > > - "%s: %s: HDR:%s, CDB:%s",
> > > > > + "%s: %s: HDR:%s, %s:%s",
> > > > > __get_str(str), __get_str(dev_name),
> > > > > __print_hex(__entry->hdr, sizeof(__entry->hdr)),
> > > > > + __get_str(tsf_type),
> > > > This breaks what current parsers expects.
> > > > Why str is not enough to distinguish between the command?
> > >
> > > Hopefully it shouldn't. Reading from user space should use the
> > > libtraceevent library, that reads the format files and extracts the raw
> > > data to find the fields. As long as the field exists, it should not break
> > > user space parsers. If it does, please let me know, and I'll gladly help
> > > change the user space code to use libtraceevent :-)
> > Hi Steve,
> > Thanks. I wasn't aware of libtraceevent - is this a new thing?
>
> Actually, it's been around almost as long as ftrace. But unfortunately,
> it's just now becoming a separate library. It was originally developed for
> trace-cmd, but has been copied into perf, power-top and rasdaemon. But
> this
> copying is inefficient and a maintenance nightmare, and we finally have the
> library as a stand alone, and hopefully will be delivered by distributions
> (I believe they are packaging it).
>
> https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
>
> Looks like distros are starting to catch on.
>
> https://packages.debian.org/unstable/libtraceevent-dev
>
>
> We are currently working on libtracefs
>
> https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
>
> Which will make it a lot easier for applications to interact with the
> tracefs file system. I'm hoping to have this ready for distros by the end
> of the year. We have applications coming that depend on these.
>
> >
> > We have a relatively sophisticated analysis platform that utilizes raw traces,
> > Among which the upiu trace is the most important and informative.
> >
> > This tool has evolved over the years, adding more and more parsers per
> need,
> > and the users are picking the appropriate parser per the trace they used.
> >
> > We will surely be glad to adopt new tracing capabilities,
>
> I think libtraceevent and libtracefs would be a much welcome addition for
> upiu trace as it would be reading raw data (very fast), and have an API
> that makes doing so much simpler. For example, I just wrote a quick program
> that checks what files an application opens (this is not in anyway
> production ready):
>
> http://rostedt.org/code/show-open-files.c
>
> > But we would prefer not to break anything.
>
> Of course!
>
> And again, I would be happy to help out in converting to this libraries. It
> will make your applications more robust, as they make it so that you do not
> need to rely on the order of fields.
>
> Note, there's plans on making these libraries python modules as well (to
> have python scripts enable and read ftrace data).
Thanks a lot for your insightful comments.
We will surely look into libtraceevent and libtracefs
Thanks,
Avri
>
> -- Steve
next prev parent reply other threads:[~2020-12-08 8:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 16:42 [PATCH v1 0/3] Three fixes for the UPIU trace Bean Huo
2020-12-06 16:42 ` [PATCH v1 1/3] scsi: ufs: Distinguish between query REQ and query RSP in query trace Bean Huo
2020-12-06 18:51 ` Bart Van Assche
2020-12-07 7:45 ` Avri Altman
2020-12-07 15:21 ` Steven Rostedt
2020-12-08 21:30 ` Bean Huo
2020-12-06 16:42 ` [PATCH v1 2/3] scsi: ufs: Distinguish between TM request UPIU and response UPIU in TM UPIU trace Bean Huo
2020-12-06 18:52 ` Bart Van Assche
2020-12-07 7:49 ` Avri Altman
2020-12-06 16:42 ` [PATCH v1 3/3] scsi: ufs: Make UPIU trace easier differentiate among CDB, OSF, and TM Bean Huo
2020-12-07 7:57 ` Avri Altman
2020-12-07 11:14 ` Bean Huo
2020-12-08 8:35 ` Avri Altman
2020-12-08 21:42 ` Bean Huo
2020-12-07 15:37 ` Steven Rostedt
2020-12-07 16:40 ` Avri Altman
2020-12-07 17:27 ` Steven Rostedt
2020-12-08 8:03 ` Avri Altman [this message]
2020-12-07 15:34 ` Steven Rostedt
2020-12-08 21:36 ` Bean Huo
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