Displaying 4 results from an estimated 4 matches for "trace_clock".
2020 Aug 11
2
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
On 11.08.20 10:12, Peter Zijlstra wrote:
> On Tue, Aug 11, 2020 at 09:57:55AM +0200, J?rgen Gro? wrote:
>> On 11.08.20 09:41, Peter Zijlstra wrote:
>>> On Fri, Aug 07, 2020 at 05:19:03PM +0200, Marco Elver wrote:
>>>
>>>> My hypothesis here is simply that kvm_wait() may be called in a place
>>>> where we get the same case I mentioned to Peter,
2020 Aug 11
2
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
On 11.08.20 10:12, Peter Zijlstra wrote:
> On Tue, Aug 11, 2020 at 09:57:55AM +0200, J?rgen Gro? wrote:
>> On 11.08.20 09:41, Peter Zijlstra wrote:
>>> On Fri, Aug 07, 2020 at 05:19:03PM +0200, Marco Elver wrote:
>>>
>>>> My hypothesis here is simply that kvm_wait() may be called in a place
>>>> where we get the same case I mentioned to Peter,
2020 Aug 11
3
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...acquire()
... tracing ...
#PF under raw_local_irq_*()
__lock_acquire()
arch_spin_lock(&graph_lock)
pv-spinlock-wait()
local_irq_save() under raw_local_irq_*()
However afaict that just made a bad situation worse. There already were
issues, take for example:
trace_clock_global()
raw_local_irq_save();
arch_spin_lock()
pv-spinlock-wait
local_irq_save()
And that has no lockdep_recursion to 'save' the say.
The tracing recursion does however avoid some of the obvious fails
there, like trace_clock calling into paravirt which then calls ba...
2020 Aug 11
3
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...acquire()
... tracing ...
#PF under raw_local_irq_*()
__lock_acquire()
arch_spin_lock(&graph_lock)
pv-spinlock-wait()
local_irq_save() under raw_local_irq_*()
However afaict that just made a bad situation worse. There already were
issues, take for example:
trace_clock_global()
raw_local_irq_save();
arch_spin_lock()
pv-spinlock-wait
local_irq_save()
And that has no lockdep_recursion to 'save' the say.
The tracing recursion does however avoid some of the obvious fails
there, like trace_clock calling into paravirt which then calls ba...