On 11/10/2022 01:43, Tvrtko Ursulin wrote:
On 09/11/2022 17:46, John Harrison wrote:
On 11/9/2022 03:05, Tvrtko Ursulin wrote:
On 08/11/2022 20:15, John Harrison wrote:
On 11/8/2022 01:01, Tvrtko Ursulin wrote:
On 07/11/2022 19:14, John Harrison wrote:
On 11/7/2022 08:17, Tvrtko Ursulin wrote:
On 07/11/2022 09:33, Tvrtko Ursulin wrote:
On 05/11/2022 01:03, Ceraolo Spurio, Daniele wrote:
On 11/4/2022 10:25 AM, John.C.Harrison@xxxxxxxxx wrote:
From: John Harrison <John.C.Harrison@xxxxxxxxx>
When trying to analyse bug reports from CI, customers, etc.
it can be
difficult to work out exactly what is happening on which GT in a
multi-GT system. So add GT oriented debug/error message
wrappers. If
used instead of the drm_ equivalents, you get the same output
but with
a GT# prefix on it.
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
The only downside to this is that we'll print "GT0: " even on
single-GT devices. We could introduce a gt->info.name and
print that, so we could have it different per-platform, but
IMO it's not worth the effort.
Reviewed-by: Daniele Ceraolo Spurio
<daniele.ceraolospurio@xxxxxxxxx>
I think it might be worth getting an ack from one of the
maintainers to make sure we're all aligned on transitioning to
these new logging macro for gt code.
Idea is I think a very good one. First I would suggest
standardising to lowercase GT in logs because:
$ grep "GT%" i915/ -r
$ grep "gt%" i915/ -r
i915/gt/intel_gt_sysfs.c: gt->i915->sysfs_gt, "gt%d",
gt->info.id))
i915/gt/intel_gt_sysfs.c: "failed to initialize
gt%d sysfs root\n", gt->info.id);
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u RC6 sysfs
files (%pe)\n",
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u RC6p sysfs
files (%pe)\n",
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u RPS sysfs
files (%pe)",
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u
punit_req_freq_mhz sysfs (%pe)",
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u throttle
sysfs files (%pe)",
i915/gt/intel_gt_sysfs_pm.c: "failed to create gt%u
media_perf_power_attrs sysfs (%pe)\n",
i915/gt/intel_gt_sysfs_pm.c: "failed to add gt%u rps defaults
(%pe)\n",
i915/i915_driver.c: drm_err(>->i915->drm, "gt%d:
intel_pcode_init failed %d\n", id, ret);
i915/i915_hwmon.c: snprintf(ddat_gt->name,
sizeof(ddat_gt->name), "i915_gt%u", i);
Just because there are 11 existing instances of one form doesn't
mean that the 275 instances that are waiting to be converted
should be done incorrectly. GT is an acronym and should be
capitalised.
Okay just make it consistent then.
Besides:
grep -r "GT " i915 | grep '"'
i915/vlv_suspend.c: drm_err(&i915->drm, "timeout disabling GT
waking\n");
i915/vlv_suspend.c: "timeout waiting for GT
wells to go %s\n",
i915/vlv_suspend.c: drm_dbg(&i915->drm, "GT register access
while GT waking disabled\n");
i915/i915_gpu_error.c: err_printf(m, "GT awake: %s\n",
str_yes_no(gt->awake));
i915/i915_debugfs.c: seq_printf(m, "GT awake? %s [%d], %llums\n",
i915/selftests/i915_gem_evict.c: pr_err("Failed to idle GT (on
%s)", engine->name);
i915/intel_uncore.c: "GT thread status wait
timed out\n");
i915/gt/uc/selftest_guc_multi_lrc.c: drm_err(>->i915->drm, "GT
failed to idle: %d\n", ret);
i915/gt/uc/selftest_guc.c: drm_err(>->i915->drm, "GT failed to
idle: %d\n", ret);
i915/gt/uc/selftest_guc.c: drm_err(>->i915->drm, "GT failed to
idle: %d\n", ret);
i915/gt/intel_gt_mcr.c: * Some GT registers are designed as
"multicast" or "replicated" registers:
i915/gt/selftest_rps.c: pr_info("%s: rps counted
%d C0 cycles [%lldns] in %lldns [%d cycles], using GT clock
frequency of %uKHz\n",
i915/gt/selftest_hangcheck.c: pr_err("[%s] GT is wedged!\n",
engine->name);
i915/gt/selftest_hangcheck.c: pr_err("GT is wedged!\n");
i915/gt/intel_gt_clock_utils.c: "GT clock
frequency changed, was %uHz, now %uHz!\n",
i915/gt/selftest_engine_pm.c: pr_err("Unable to flush
GT pm before test\n");
i915/gt/selftest_engine_pm.c: pr_err("GT failed to idle\n");
i915/i915_sysfs.c: "failed to register GT
sysfs directory\n");
i915/intel_uncore.h: * of the basic non-engine GT registers
(referred to as "GSI" on
i915/intel_uncore.h: * newer platforms, or "GT block" on
older platforms)? If so, we'll
Then there is a question of naming. Are we okay with GT_XXX or,
do we want intel_gt_, or something completely different. I
don't have a strong opinion at the moment so I'll add some more
folks to Cc.
You mean GT_ERR("msg") vs intel_gt_err("msg")? Personally, I
would prefer just gt_err("msg") to keep it as close to the
official drm_* versions as possible. Print lines tend to be
excessively long already. Taking a 'gt' parameter instead of a
'>->i915->drm' parameter does help with that but it seems like
calling the wrapper intel_gt_* is shooting ourselves in the foot
on that one. And GT_ERR vs gt_err just comes down to the fact
that it is a macro wrapper and therefore is required to be in
upper case.
There was a maintainer level mini-discussion on this topic which
I will try to summarise.
Main contention point was the maintenance cost and generally an
undesirable pattern of needing to add many
subsystem/component/directory specific macros. Which then
typically need extra flavours and so on. But over verbosity of the
How many versions are you expecting to add? Beyond the tile
instance, what further addressing requirements are there? The
card instance is already printed as part of the PCI address. The
only other reason to add per component wrappers would be to wrap
the mechanism for getting from some random per component object
back to the intel_gt structure. But that is hardware a new issue
being added by this wrapper. It is also not a requirement. Much
of the code has a gt pointer already. For the parts that don't,
some of it would be a trivial engine->gt type dereference, some
of it is a more complex container_of type construction. But for
those, the given file will already have multiple instances of
that already (usually as the first or second line of the function
- 'intel_gt *gt = fancy_access_method(my_obj)' so adding one or
two more of those as necessary is not making the code harder to
read.
code is obviously also bad, so one compromise idea was to add a
macro which builds the GT string and use drm logging helpers
directly. This would be something like:
drm_err(GT_LOG("something went wrong ret=%d\n", gt), ret);
drm_info(GT_LOG(...same...));
Seriously? As above, some of these lines are already way too
long, this version makes them even longer with no obvious
benefit. Worse, it makes it harder to read what is going on. It
is much less intuitive to read than just replacing the drm_err
itself. And having two sets of parenthesis with some parameters
inside the first and some only inside the second is really
horrid! Also, putting the 'gt' parameter in the middle just
confuses it with the rest of the printf arguments even though
there is no %d in the string for it. So now a quick glances tells
you that your code is wrong because you have three format
specifiers but four parameters.
Whereas, just replacing drm_err with gt_err (or GT_ERR or
intel_gt_err) keeps everything else consistent. The first
parameter changes from 'drm' to 'gt' but is still the master
object parameter and it matches the function/macro prefix so
inherently looks correct. Then you have your message plus
parameters. No confusing orders, no confusing parenthesis, no
excessive macro levels, no confusion at all. Just nice simple,
easy to read, easy to maintain code.
I am personally okay with gt_err/GT_ERR some other folks might
object though. And I can also understand the argument why it is
better to not have to define gt_err, gt_warn, gt_info, gt_notice,
gt_debug, gt_err_ratelimited, gt_warn_once.. and instead have only
one macro.
A small set of trivial macro definitions vs a complicated and
unreadable construct on every single print? Erm, isn't that the
very definition of abstracting to helpers as generally required by
every code review ever?
And what 'other folks might object'? People already CC'd? People
outside of i915?
Because of that I was passing on to you the compromise option.
It maybe still has net space savings since we wouldn't have to be
repeating the gt->i915->drm whatever and gt->info.id on every line.
You are free to try the most compact one and see how hard those
objections will be.
Um. I already did. This patch. And you are the only person to have
objected in any manner at all.
Where I have objected?
Only in everything you have written. Or are you saying that actually I
???
could have just taken the r-b from Daniele and merged it while
completely ignoring everything you have said because you didn't say
'NACK' at the top of your email?
No, but because we don't do that while there is an ongoing discussion.
Which is exactly my point. If it is not an ack or r-b then by definition
it is an objection.
I was a) asking to convert all gt/ within one kernel release, b)
transferring the maintainer discussion from IRC to this email chain
to outlay one alternative, for which I said I could see the pros and
cons of both, and c) raised the naming question early since that can
usually become a churn point later on when we have large scale code
transformations.
As said, FWIW you have my ack for GT_XXX naming and approach, but
please do convert the whole of gt/ so we don't ship with a mish-mash
of log messages.
That sounds like a quite a lot of objections to me - don't do it that
way, do it this way; fine do it that way but expect lots of
complaints when you do; oh all right, do it that way but re-write the
entire driver all at once.
No, I'll repeat what I said one last time.
I said it's good idea, raised the topic of naming, since it is good to
get consensus before starting a wide renaming exercise. I also chatted
with other maintainers and passed on here one alternative proposed,
with its pros and cons. Finally I said your initial approach has my
ack at least, even though not everyone liked it. And I asked to
convert all gt/, since I think it is a good idea, and frankly it's not
a very big ask. It is just how it works.
I really don't get the 'we must not ship with a mish-mash of log
messages' argument. It's hardly like the current total mish-mash of
DRM_DEBUG, DRM_DEBUG_DRIVER, pr_dbg, drm_dbg, ... is even remotely
consistent. It's also not like the patch is massively changing the
format of the output messages. So some prints get a useful extra
three characters in advance of others. Does anyone care? Would anyone
except us even notice?
Is it really a problem to merge this patch now to get the process
started? And other sub-components get updated as and when people get
the time to do them? You could maybe even help rather than posting
It can be a problem. You opened up a topic which leads to an overall
improvement and if we merge churn before we decide on the final
direction, then we just get more churn later.
completely conflicting patch sets that basically duplicate all the
effort for no actual benefit.
Completely conflicting?
Yours:
drivers/gpu/drm/i915/gt/uc/intel_guc.c | 25 +++--
drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c | 9 +-
.../gpu/drm/i915/gt/uc/intel_guc_capture.c | 50 ++++------
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 9 +-
drivers/gpu/drm/i915/gt/uc/intel_guc_fw.c | 17 ++--
drivers/gpu/drm/i915/gt/uc/intel_guc_log.c | 49 +++++-----
drivers/gpu/drm/i915/gt/uc/intel_guc_rc.c | 3 +-
drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 6 +-
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 56 ++++++------
drivers/gpu/drm/i915/gt/uc/intel_huc.c | 20 ++--
drivers/gpu/drm/i915/gt/uc/intel_uc.c | 84 ++++++++---------
drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 91 +++++++++----------
drivers/gpu/drm/i915/gt/uc/selftest_guc.c | 36 ++++----
.../drm/i915/gt/uc/selftest_guc_hangcheck.c | 22 ++---
.../drm/i915/gt/uc/selftest_guc_multi_lrc.c | 10 +-
15 files changed, 228 insertions(+), 259 deletions(-)
Mine:
drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 23 ++++++----
.../drm/i915/gt/intel_execlists_submission.c | 13 +++---
drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 4 +-
drivers/gpu/drm/i915/gt/intel_gt.c | 4 +-
drivers/gpu/drm/i915/gt/intel_gt_irq.c | 8 ++--
drivers/gpu/drm/i915/gt/intel_rps.c | 6 ++-
drivers/gpu/drm/i915/gt/intel_workarounds.c | 43 +++++++++++--------
.../gpu/drm/i915/gt/intel_workarounds_types.h | 4 ++
.../gpu/drm/i915/gt/selftest_workarounds.c | 4 +-
drivers/gpu/drm/i915/i915_debugfs.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 2 +-
drivers/gpu/drm/i915/i915_getparam.c | 2 +-
drivers/gpu/drm/i915/i915_irq.c | 12 +++---
drivers/gpu/drm/i915/i915_perf.c | 14 +++---
drivers/gpu/drm/i915/i915_query.c | 12 +++---
drivers/gpu/drm/i915/i915_sysfs.c | 3 +-
drivers/gpu/drm/i915/i915_vma.c | 16 ++++---
drivers/gpu/drm/i915/intel_uncore.c | 21 +++++----
19 files changed, 116 insertions(+), 81 deletions(-)
I deliberately did not touch gt/uc so they don't touch a single same
file!
Unless you are referring to the fact gt logging will need to touch
some of the same lines my patch touches. Well yes, some, not all, and
I reckoned it will be much quicker since there aren't really any
contentious points with DRM_XXX -> drm_xxx. Plus I added struct
intel_gt or whatever or it wasn't before so it would make your patch
easier/smaller.
Except that it is quite clearly a change that is 'still under
discussion' and is quite clearly changing exactly the same lines of code
in a number of places. Therefore, by your definition, your patch set
cannot be merged because it is causing 'churn'. Alternatively, your set
can be merged because we don't actually care that a few lines will get
changed one way and then quickly changed another way in a follow up
patch and the overall benefit is worth the 'churn'. In which case
exactly the same rule should apply to this patch set. Merge something
that adds immediate benefit and if necessary update it to a better
version later.
Of course, there is also the view that you have just taken the task over
by posting a more encompassing change that cleans up debug prints in the
whole of i915. Therefore it is now up to you to update all
sub-components to use appropriate prints - GT, KMS, GuC, Gem, etc..
because "frankly it's not a very big ask. It is just how it works".
John.
Regards,
Tvrtko
