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?
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.
Regards,
Tvrtko
