From: David Ahern <dsahern@gmail.com>
To: Stephane Eranian <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
mingo@elte.hu, acme@redhat.com, robert.richter@amd.com,
ming.m.lin@intel.com, andi@firstfloor.org, asharma@fb.com,
ravitillo@lbl.gov, vweaver1@eecs.utk.edu,
khandual@linux.vnet.ibm.com
Subject: Re: [PATCH v5 16/18] perf: enable reading of perf.data files from different ABI rev
Date: Tue, 07 Feb 2012 10:57:36 -0700 [thread overview]
Message-ID: <4F316610.1030105@gmail.com> (raw)
In-Reply-To: <CABPqkBR5j9wxNfSReXeLWmEdUHJmhnQUQ4W2mBqY-MatNSo0sA@mail.gmail.com>
On 02/07/2012 10:42 AM, Stephane Eranian wrote:
>>> Well, the current code solves the problem once and for all. Old tools
>>> can still read new files and vice-versa. If you think that's a problem I
>>> can simply bail out if sz > our_sz.
>>
>> My sensitivity on this is when endianness is broken it is a nightmare to
>> find. You end up lacing the code with printfs trying to find which size
>> field is going off the charts making the parsing of the file fail - or
>> worse the sizes are slightly off and you get non-sense out.
>>
>> New commands should be able to read old files; old commands reading new
>> files is a bit of a stretch in that the code has to be future-proofed.
>> It seems like a reasonable requirement for data files to be examined by
>> a command of the same vintage or newer as the command that wrote the file.
>>
> Fine then, I can simply strip that part of the code and return an
> error is sz > our_sz.
> How about that?
That's my preference - with a nice grep-able error message about an
unexpected attr size.
David
next prev parent reply other threads:[~2012-02-07 17:57 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-02 12:54 [PATCH v5 00/18] perf: add support for sampling taken branches Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 01/18] perf: add generic taken branch sampling support Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 02/18] perf: add Intel LBR MSR definitions Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 03/18] perf: add Intel X86 LBR sharing logic Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 04/18] perf: sync branch stack sampling with X86 precise_sampling Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 05/18] perf: add Intel X86 LBR mappings for PERF_SAMPLE_BRANCH filters Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 06/18] perf: disable LBR support for older Intel Atom processors Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 07/18] perf: implement PERF_SAMPLE_BRANCH for Intel X86 Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 08/18] perf: add LBR software filter support " Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 09/18] perf: disable PERF_SAMPLE_BRANCH_* when not supported Stephane Eranian
2012-02-06 19:23 ` Peter Zijlstra
2012-02-06 19:59 ` Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 10/18] perf: add hook to flush branch_stack on context switch Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 11/18] perf: add code to support PERF_SAMPLE_BRANCH_STACK Stephane Eranian
2012-02-06 18:06 ` Arnaldo Carvalho de Melo
2012-02-07 14:11 ` Stephane Eranian
2012-02-07 15:21 ` Arnaldo Carvalho de Melo
2012-02-02 12:54 ` [PATCH v5 12/18] perf: add support for sampling taken branch to perf record Stephane Eranian
2012-02-06 18:08 ` Arnaldo Carvalho de Melo
2012-02-02 12:54 ` [PATCH v5 13/18] perf: add support for taken branch sampling to perf report Stephane Eranian
2012-02-06 18:14 ` Arnaldo Carvalho de Melo
2012-02-02 12:54 ` [PATCH v5 14/18] perf: fix endianness detection in perf.data Stephane Eranian
2012-02-06 18:17 ` Arnaldo Carvalho de Melo
2012-02-06 18:18 ` Stephane Eranian
2012-02-06 21:47 ` David Ahern
2012-02-06 22:06 ` Arnaldo Carvalho de Melo
2012-02-06 22:29 ` David Ahern
2012-02-07 14:13 ` Stephane Eranian
2012-02-07 14:38 ` Arnaldo Carvalho de Melo
2012-02-17 9:42 ` [tip:perf/core] perf tools: " tip-bot for Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 15/18] perf: add ABI reference sizes Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 16/18] perf: enable reading of perf.data files from different ABI rev Stephane Eranian
2012-02-06 18:19 ` Arnaldo Carvalho de Melo
2012-02-06 18:22 ` Arnaldo Carvalho de Melo
2012-02-07 7:03 ` Anshuman Khandual
2012-02-07 14:52 ` Arnaldo Carvalho de Melo
2012-02-06 22:19 ` David Ahern
2012-02-07 15:50 ` Stephane Eranian
2012-02-07 16:41 ` David Ahern
2012-02-07 17:42 ` Stephane Eranian
2012-02-07 17:57 ` David Ahern [this message]
2012-02-02 12:54 ` [PATCH v5 17/18] perf: fix bug print_event_desc() Stephane Eranian
2012-02-02 12:54 ` [PATCH v5 18/18] perf: make perf able to read file from older ABIs Stephane Eranian
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=4F316610.1030105@gmail.com \
--to=dsahern@gmail.com \
--cc=acme@redhat.com \
--cc=andi@firstfloor.org \
--cc=asharma@fb.com \
--cc=eranian@google.com \
--cc=khandual@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=ming.m.lin@intel.com \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=ravitillo@lbl.gov \
--cc=robert.richter@amd.com \
--cc=vweaver1@eecs.utk.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.