Hi Maciej,
On 1/22/2024 11:58 PM, Maciej Wieczór-Retman wrote:
On 2024-01-22 at 08:32:36 -0800, Reinette Chatre wrote:
Hi Maciej,
On 1/21/2024 11:56 PM, Maciej Wieczór-Retman wrote:
Hi!
On 2024-01-19 at 08:39:31 -0800, Reinette Chatre wrote:
Hi Maciej,
On 1/18/2024 11:37 PM, Maciej Wieczór-Retman wrote:
On 2024-01-18 at 09:15:46 -0800, Reinette Chatre wrote:
On 1/18/2024 4:02 AM, Maciej Wieczór-Retman wrote: > On 2024-01-17 at 10:49:06 -0800, Reinette Chatre wrote: >> On 1/17/2024 12:26 AM, Maciej Wieczór-Retman wrote: >>> On 2024-01-08 at 14:42:11 -0800, Reinette Chatre wrote: >>>> On 12/12/2023 6:52 AM, Maciej Wieczor-Retman wrote:
>>>>> + bit_center = count_bits(full_cache_mask) / 2; >>>>> + cont_mask = full_cache_mask >> bit_center; >>>>> + >>>>> + /* Contiguous mask write check. */ >>>>> + snprintf(schemata, sizeof(schemata), "%lx", cont_mask); >>>>> + ret = write_schemata("", schemata, uparams->cpu, test->resource); >>>>> + if (ret) >>>>> + return ret; >>>> >>>> How will user know what failed? I am seeing this single test exercise a few scenarios >>>> and it is not obvious to me if the issue will be clear if this test, >>>> noncont_cat_run_test(), fails. >>> >>> write_schemata() either succeeds with '0' or errors out with a negative value. If >>> the contiguous mask write fails, write_schemata should print out what was wrong >>> and I believe that the test will report an error rather than failure. >> >> Right. I am trying to understand whether the user will be able to decipher what failed >> in case there is an error. Seems like in this case the user is expected to look at the >> source code of the test to understand what the test was trying to do at the time it >> encountered the failure. In this case user may be "lucky" that this test only has >> one write_schemata() call _not_ followed by a ksft_print_msg() so user can use that >> reasoning to figure out which write_schemata() failed to further dig what test was >> trying to do. > > When a write_schemata() is executed the string that is being written gets > printed. If there are multiple calls in a single tests and one fails I'd imagine > it would be easy for the user to figure out which one failed.
It would be easy for the user the figure out if (a) it is obvious to the user what schema a particular write_schema() call attempted to write and (b) all the write_schema() calls attempt to write different schema.
As for (b) depends on what you meant. Other tests that run more than one write_schemata() use different ones every time (CAT, MBM, MBA). Do you suggest that the non-contiguous test should attempt more schematas? For example shift the bit hole from one side to the other? I assumed one CBM with a centered bit hole would be enough to check if non-contiguous CBM feature works properly and more CBMs would be redundant.
Let me try with an example. Scenario 1: The test has the following code: ... write_schemata(..., "0xfff", ...); ... write_schemata(..., "0xf0f", ...); ...
Scenario 2: The test has the following code: ... write_schemata(..., "0xfff", ...); ... write_schemata(..., "0xfff", ...); ...
A failure of either write_schemata() in scenario 1 will be easy to trace since the schemata attempted is different in each case. The schemata printed by the write_schemata() error message can thus easily be connected to the specific write_schemata() call. A failure of either write_schemata() in scenario 2 is not so obvious since they both attempted the same schemata so the error message printed by write_schemata() could belong to either.
I'm sorry to drag this thread out but I want to be sure if I'm right or are you suggesting something and I missed it?
Please just add a ksft_print_msg() to noncont_cat_run_test() when this write_schemata() fails.
My point all along was that if write_schemata() fails it already prints out all the necessary information. I'd like to avoid adding redundant messages so please take a look at how it looks now:
Please consider that there may be different perspectives of "necessary information".
I injected write_schemata() with an error so it will take a path as if write() failed with 'Permission denied' as a reason. Here is the output for L3 non-contiguous CAT test:
[root@spr1 ~]# ./resctrl_tests -t L3_NONCONT_CAT TAP version 13 # Pass: Check kernel supports resctrl filesystem # Pass: Check resctrl mountpoint "/sys/fs/resctrl" exists # resctrl filesystem not mounted # dmesg: [ 18.579861] resctrl: L3 allocation detected # dmesg: [ 18.590395] resctrl: L2 allocation detected # dmesg: [ 18.595181] resctrl: MB allocation detected # dmesg: [ 18.599963] resctrl: L3 monitoring detected 1..1 # Starting L3_NONCONT_CAT test ... # Mounting resctrl to "/sys/fs/resctrl" # Write schema "L3:0=ff" to resctrl FS # write() failed : Permission denied not ok 1 L3_NONCONT_CAT: test # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0
Understood.
Of course if you still think adding a ksft_print_msg() there would be meaningful I'll try to write a sensible message. But I hope you can see what I meant when I wrote that the user could already easily see what failed.
I do still believe that it will be helpful if there is a ksft_print_msg() with something like "Unable to write contiguous CBM" or "Write of contiguous CBM failed" or ... ?
Reinette