From: Michael Ellerman <mpe@ellerman•id.au>
To: Balbir Singh <bsingharora@gmail•com>,
linuxppc-dev <linuxppc-dev@ozlabs•org>
Cc: Paul Mackerras <paulus@samba•org>, Nicholas Piggin <npiggin@gmail•com>
Subject: Re: [RFC] [PATCH] Trace TLBIE's
Date: Wed, 23 Nov 2016 21:15:30 +1100 [thread overview]
Message-ID: <87polmtscd.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <3dcd0c76-46fd-cb7a-945d-4b5a679fa544@gmail.com>
Balbir Singh <bsingharora@gmail•com> writes:
> Just a quick patch to trace tlbie(l)'s. The idea being that it can be
> enabled when we suspect corruption or when we need to see if we are doing
> the right thing during flush. I think the format can be enhanced to
> make it nicer (expand the RB/RS/IS/L cases in more detail). For now I am
> sharing the idea to get inputs
>
> A typical trace might look like this
>
>
> <...>-5141 [062] 1354.486693: tlbie:
> tlbie with lpid 0, local 0, rb=7b5d0ff874f11f1, rs=0, ric=0 prs=0 r=0
> systemd-udevd-2584 [018] 1354.486772: tlbie:
> tlbie with lpid 0, local 0, rb=17be1f421adc10c1, rs=0, ric=0 prs=0 r=0
> ...
>
> qemu-system-ppc-5371 [016] 1412.369519: tlbie:
> tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0
> qemu-system-ppc-5377 [056] 1421.687262: tlbie:
> tlbie with lpid 1, local 0, rb=5f04edffa00c11c1, rs=1, ric=0 prs=0 r=0
My first reaction is "why the hell do we have so many open-coded
tlbies". So step one might be to add a static inline helper, that way we
don't have to add the trace_tlbie() in so many places.
Also in some of them you call trace_tlbie() before the
eieio/tlbsync/ptesync. Which may not be wrong, but looks worrying at
first glance.
But overall I guess it's OK. We'd want to do a quick benchmark to make
sure it's not adding any overhead.
cheers
next prev parent reply other threads:[~2016-11-23 10:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-23 8:06 [RFC] [PATCH] Trace TLBIE's Balbir Singh
2016-11-23 10:15 ` Michael Ellerman [this message]
2016-11-23 11:40 ` Balbir Singh
2017-04-06 5:32 ` Alistair Popple
2017-04-06 6:03 ` Michael Ellerman
2017-04-06 6:23 ` Balbir Singh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87polmtscd.fsf@concordia.ellerman.id.au \
--to=mpe@ellerman$(echo .)id.au \
--cc=bsingharora@gmail$(echo .)com \
--cc=linuxppc-dev@ozlabs$(echo .)org \
--cc=npiggin@gmail$(echo .)com \
--cc=paulus@samba$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox