Re: [PATCH 00/24] Complete EEVDF

[Sven Schnelle <svens@linux.ibm.com>]

Sven Schnelle <svens@linux.ibm.com> writes:

> Peter Zijlstra <peterz@infradead.org> writes:
>
>> Hi all,
>>
>> So after much delay this is hopefully the final version of the EEVDF patches.
>> They've been sitting in my git tree for ever it seems, and people have been
>> testing it and sending fixes.
>>
>> I've spend the last two days testing and fixing cfs-bandwidth, and as far
>> as I know that was the very last issue holding it back.
>>
>> These patches apply on top of queue.git sched/dl-server, which I plan on merging
>> in tip/sched/core once -rc1 drops.
>>
>> I'm hoping to then merge all this (+- the DVFS clock patch) right before -rc2.
>>
>>
>> Aside from a ton of bug fixes -- thanks all! -- new in this version is:
>>
>>  - split up the huge delay-dequeue patch
>>  - tested/fixed cfs-bandwidth
>>  - PLACE_REL_DEADLINE -- preserve the relative deadline when migrating
>>  - SCHED_BATCH is equivalent to RESPECT_SLICE
>>  - propagate min_slice up cgroups
>>  - CLOCK_THREAD_DVFS_ID
>
> I'm seeing crashes/warnings like the following on s390 with linux-next 20240909:
>
> Sometimes the system doesn't manage to print a oops, this one is the best i got:
>
> [..]
> This happens when running the strace test suite. The system normaly has
> 128 CPUs. With this configuration the crash doesn't happen, but when
> disabling all but four CPUs and running 'make check -j16' in the strace
> test suite the crash is almost always reproducable.

I failed to add the log from git bisect. Unfortunately i had to skip
some commit because the kernel didn't compile:

git bisect start
# status: waiting for both good and bad commits
# bad: [100cc857359b5d731407d1038f7e76cd0e871d94] Add linux-next specific files for 20240909
git bisect bad 100cc857359b5d731407d1038f7e76cd0e871d94
# status: waiting for good commit(s), bad commit known
# good: [da3ea35007d0af457a0afc87e84fddaebc4e0b63] Linux 6.11-rc7
git bisect good da3ea35007d0af457a0afc87e84fddaebc4e0b63
# good: [df20078b9706977cc3308740b56993cf27665f90] Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
git bisect good df20078b9706977cc3308740b56993cf27665f90
# good: [609f9e1b6242e7158ce96f9124372601997ce56c] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git
git bisect good 609f9e1b6242e7158ce96f9124372601997ce56c
# skip: [664c3413e9a6c345a6c926841358314be9da8309] Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
git bisect skip 664c3413e9a6c345a6c926841358314be9da8309
# good: [16531118ba63dd9bcd65203d04a9c9d6f6800547] iio: bmi323: peripheral in lowest power state on suspend
git bisect good 16531118ba63dd9bcd65203d04a9c9d6f6800547
# bad: [d9c7ac7f8bfb16f431daa7c77bdfe2b163361ead] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git
git bisect bad d9c7ac7f8bfb16f431daa7c77bdfe2b163361ead
# bad: [05536babd768b38d84ad168450f48634a013603d] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
git bisect bad 05536babd768b38d84ad168450f48634a013603d
# good: [dabef94a179957db117db344b924e5d5c4074e5f] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
git bisect good dabef94a179957db117db344b924e5d5c4074e5f
# bad: [d4886a325947ecae6867fc858657062211aae3b9] Merge branch into tip/master: 'locking/core'
git bisect bad d4886a325947ecae6867fc858657062211aae3b9
# bad: [51c095bee5c77590d43519f03179342e910d333c] Merge branch into tip/master: 'core/core'
git bisect bad 51c095bee5c77590d43519f03179342e910d333c
# bad: [fc1892becd5672f52329a75c73117b60ac7841b7] sched/eevdf: Fixup PELT vs DELAYED_DEQUEUE
git bisect bad fc1892becd5672f52329a75c73117b60ac7841b7
# good: [ae04f69de0bef93c7086cf2983dbc8e8fd624ebe] sched/rt: Rename realtime_{prio, task}() to rt_or_dl_{prio, task}()
git bisect good ae04f69de0bef93c7086cf2983dbc8e8fd624ebe
# good: [abc158c82ae555078aa5dd2d8407c3df0f868904] sched: Prepare generic code for delayed dequeue
git bisect good abc158c82ae555078aa5dd2d8407c3df0f868904
# skip: [781773e3b68031bd001c0c18aa72e8470c225ebd] sched/fair: Implement ENQUEUE_DELAYED
git bisect skip 781773e3b68031bd001c0c18aa72e8470c225ebd
# skip: [e1459a50ba31831efdfc35278023d959e4ba775b] sched: Teach dequeue_task() about special task states
git bisect skip e1459a50ba31831efdfc35278023d959e4ba775b
# skip: [a1c446611e31ca5363d4db51e398271da1dce0af] sched,freezer: Mark TASK_FROZEN special
git bisect skip a1c446611e31ca5363d4db51e398271da1dce0af
# good: [e28b5f8bda01720b5ce8456b48cf4b963f9a80a1] sched/fair: Assert {set_next,put_prev}_entity() are properly balanced
git bisect good e28b5f8bda01720b5ce8456b48cf4b963f9a80a1
# skip: [f12e148892ede8d9ee82bcd3e469e6d01fc077ac] sched/fair: Prepare pick_next_task() for delayed dequeue
git bisect skip f12e148892ede8d9ee82bcd3e469e6d01fc077ac
# skip: [152e11f6df293e816a6a37c69757033cdc72667d] sched/fair: Implement delayed dequeue
git bisect skip 152e11f6df293e816a6a37c69757033cdc72667d
# skip: [2e0199df252a536a03f4cb0810324dff523d1e79] sched/fair: Prepare exit/cleanup paths for delayed_dequeue
git bisect skip 2e0199df252a536a03f4cb0810324dff523d1e79
# bad: [54a58a78779169f9c92a51facf6de7ce94962328] sched/fair: Implement DELAY_ZERO
git bisect bad 54a58a78779169f9c92a51facf6de7ce94962328
# only skipped commits left to test
# possible first bad commit: [54a58a78779169f9c92a51facf6de7ce94962328] sched/fair: Implement DELAY_ZERO
# possible first bad commit: [152e11f6df293e816a6a37c69757033cdc72667d] sched/fair: Implement delayed dequeue
# possible first bad commit: [e1459a50ba31831efdfc35278023d959e4ba775b] sched: Teach dequeue_task() about special task states
# possible first bad commit: [a1c446611e31ca5363d4db51e398271da1dce0af] sched,freezer: Mark TASK_FROZEN special
# possible first bad commit: [781773e3b68031bd001c0c18aa72e8470c225ebd] sched/fair: Implement ENQUEUE_DELAYED
# possible first bad commit: [f12e148892ede8d9ee82bcd3e469e6d01fc077ac] sched/fair: Prepare pick_next_task() for delayed dequeue
# possible first bad commit: [2e0199df252a536a03f4cb0810324dff523d1e79] sched/fair: Prepare exit/cleanup paths for delayed_dequeue