Mahesh Jagannath Salgaonkar <mah...@linux.ibm.com> writes:
> On 12/8/20 4:16 PM, Ganesh wrote:
>>
>> On 12/8/20 4:01 PM, Michael Ellerman wrote:
>>> Ganesh Goudar <ganes...@linux.ibm.com> writes:
>>>> diff --git a/arch/powerpc/include/asm/paca.h
>>>> b/arch/powerpc/include/asm/paca.h
>>>> index 9454d29ff4b4..4769954efa7d 100644
>>>> --- a/arch/powerpc/include/asm/paca.h
>>>> +++ b/arch/powerpc/include/asm/paca.h
>>>> @@ -273,6 +274,17 @@ struct paca_struct {
>>>> #ifdef CONFIG_MMIOWB
>>>> struct mmiowb_state mmiowb_state;
>>>> #endif
>>>> +#ifdef CONFIG_PPC_BOOK3S_64
>>>> + int mce_nest_count;
>>>> + struct machine_check_event mce_event[MAX_MC_EVT];
>>>> + /* Queue for delayed MCE events. */
>>>> + int mce_queue_count;
>>>> + struct machine_check_event mce_event_queue[MAX_MC_EVT];
>>>> +
>>>> + /* Queue for delayed MCE UE events. */
>>>> + int mce_ue_count;
>>>> + struct machine_check_event mce_ue_event_queue[MAX_MC_EVT];
>>>> +#endif /* CONFIG_PPC_BOOK3S_64 */
>>>> } ____cacheline_aligned;
>>> How much does this expand the paca by?
>>
>> Size of paca is 4480 bytes, these add up another 2160 bytes, so expands
>> it by 48%.
>
> Should we dynamically allocate the array sizes early as similar to that
> of paca->mce_faulty_slbs so that we don't bump up paca size ?
Yeah I think that would be preferable.
That way those allocations can be normal node-local allocations on bare
metal, or when using radix. (Or even on KVM).
In fact what we probably want is a separate struct for all the MCE
related data, eg something like:
struct mce_stuff {
int nest_count;
/* Queue for delayed MCE events. */
int queue_count;
/* Queue for delayed MCE UE events. */
int mce_ue_count;
struct machine_check_event events[MAX_MC_EVT];
struct machine_check_event event_queue[MAX_MC_EVT];
struct machine_check_event ue_event_queue[MAX_MC_EVT];
};
And then you allocate one of those per CPU, inside the RMO for pseries
with hash, and node-local otherwise.
cheers
