[pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operations

[pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operations

[Christoph Lameter]

This patchset introduces preemption checks for __this_cpu operations.

First we add new raw_cpu operations that perform this cpu operations
without preempt checks. 

The second patch then adds the preempt checks by modifying the
__this_cpu macros in include/linux/percpu.h

V2->V3:
	- Subject line in the raw_cpu_ops patch had ; instead of :.
	  Guess I am getting old.
	- Improve descriptions and variable names.
	- Run tests again with kvm to verify that it still works.
		A) No warnings with just the patches applied
		B) Lots of warnings with CONFIG_DEBUG_THIS_CPU_OPERATIONS enabled
		C) No warnings with 3 core patches applied that simply convert
			__this_cpu operations to raw_cpu_ops.

V1->V2:
	- Reuse preemption check logic in lib/smp_processor_id.c
	- Add CONFIG_DEBUG_THIS_CPU_OPERATIONS
	- Remove conversions to the use of raw_cpu_ops since
	  these may require some discussion first.

Re: [pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operations

[Ingo Molnar]

* Christoph Lameter <cl@linux.com> wrote:

> This patchset introduces preemption checks for __this_cpu operations.
> 
> First we add new raw_cpu operations that perform this cpu operations
> without preempt checks. 
> 
> The second patch then adds the preempt checks by modifying the
> __this_cpu macros in include/linux/percpu.h

Patch submission technical feedback: your 0/2 mail is still non-standard, 
it arrived out of order and looks broken - why isn't it threaded to the 
other patches? Here is how it looks like in my mailer:

You should either use "git send-email" to create proper threading (you can 
use that even if you originally created the series via Quilt), or you can 
send them manually with proper threading (that's what I did years ago when 
I still used Quilt).

You should not burden lkml with broken-format submissions, especially as 
the size of this patch series is expected to grow in the future, as you 
fix false positive warnings.

64877   C Oct 03 Christoph Lamet ( 206) ┬─>[pchecks v2 2/2] percpu: Add preemption checks to __this_cpu ops
64878   C Oct 03 Christoph Lamet ( 121) └─>[pchecks v2 1/2] percpu: Add raw_cpu_ops
64879   C Oct 03 Christoph Lamet (  24) [pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operatio

> V2->V3:
> 	- Subject line in the raw_cpu_ops patch had ; instead of :.
> 	  Guess I am getting old.
> 	- Improve descriptions and variable names.
> 	- Run tests again with kvm to verify that it still works.
> 		A) No warnings with just the patches applied
> 		B) Lots of warnings with CONFIG_DEBUG_THIS_CPU_OPERATIONS enabled

Patch series technical feedback: it's standard kernel debugging 
infrastructure policy that all warnings that trigger with debugging 
enabled need to be fixed, so your series will need to fix them before I 
can move forward with merging these patches.

Please fix these technical shortcomings before your next submission.

Thanks,

	Ingo

Re: [pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operations

[Peter Zijlstra]

User-Agent: quilt/0.50-1

You might want to upgrade your quilt the latest version is 0.60-1 and
there's talk of actually releasing something newer.

Re: [pchecks v2 0/2] percpu v3: Implement Preemption checks for __this_cpu operations

[Ingo Molnar]

* Peter Zijlstra <peterz@infradead.org> wrote:

> User-Agent: quilt/0.50-1
> 
> You might want to upgrade your quilt the latest version is 0.60-1 and
> there's talk of actually releasing something newer.

Another technical problem with the submission is the lack of 'PATCH' tags 
for the patches - it's the standard and ther are folks search lkml based 
on that pattern.

See Documentation/SubmittingPatches:

 | 11) Include PATCH in the subject
 |
 | Due to high e-mail traffic to Linus, and to linux-kernel, it is common 
 | convention to prefix your subject line with [PATCH].  This lets Linus 
 | and other kernel developers more easily distinguish patches from other 
 | e-mail discussions.

Note that all of the technical problems we noted need to be fixed before 
the next resubmission, not just some.

Thanks,

	Ingo