Counter API

[Adrian Chadd]

On 3 February 2017 at 05:03, Alexandre Martins
<alexandre.martins at stormshield.eu> wrote:
> Hi Kontantin.
>
> Your patch compille and run great in a 32 bit environment. I don't have a 64
> bit one to check.
>
> Thank you for your support.

hm! Should this be committed to -head?



-adrian

>
> Best regards
>
> Alexandre
>
> Le jeudi 2 février 2017, 18:01:59 Konstantin Belousov a écrit :
>> On Thu, Feb 02, 2017 at 04:38:08PM +0100, Alexandre Martins wrote:
>> > Hi all,
>> >
>> > Our companie is curently tracking performance issue with our ARM product.
>> >
>> > We have seen that counter API was migrated from intrinsic to atomic.
>> >
>> > https://svnweb.freebsd.org/base?view=revision&revision=269406
>> >
>> > But there is still the calls to critical_enter/leave in the macro
>> > counter_enter/leave.
>> >
>> > Is that needed ? Can we remove that ?
>>
>> Try this.  I did not even compiled the patch.
>>
>> diff --git a/sys/arm/include/counter.h b/sys/arm/include/counter.h
>> index c4da91f7a14..950516e1616 100644
>> --- a/sys/arm/include/counter.h
>> +++ b/sys/arm/include/counter.h
>> @@ -31,12 +31,9 @@
>>
>>  #include <sys/pcpu.h>
>>  #include <machine/atomic.h>
>> -#ifdef INVARIANTS
>> -#include <sys/proc.h>
>> -#endif
>>
>> -#define      counter_enter() critical_enter()
>> -#define      counter_exit()  critical_exit()
>> +#define      counter_enter() do {} while (0)
>> +#define      counter_exit()  do {} while (0)
>>
>>  #ifdef IN_SUBR_COUNTER_C
>>
>> @@ -55,7 +52,7 @@ counter_u64_fetch_inline(uint64_t *p)
>>       int i;
>>
>>       r = 0;
>> -     for (i = 0; i < mp_ncpus; i++)
>> +     CPU_FOREACH(i)
>>               r += counter_u64_read_one((uint64_t *)p, i);
>>
>>       return (r);
>> @@ -78,18 +75,13 @@ counter_u64_zero_inline(counter_u64_t c)
>>  }
>>  #endif
>>
>> -#define      counter_u64_add_protected(c, inc)       do {    \
>> -     CRITICAL_ASSERT(curthread);                     \
>> -     atomic_add_64((uint64_t *)zpcpu_get(c), (inc)); \
>> -} while (0)
>> +#define      counter_u64_add_protected(c, inc)       counter_u64_add(c, inc)
>>
>>  static inline void
>>  counter_u64_add(counter_u64_t c, int64_t inc)
>>  {
>>
>> -     counter_enter();
>> -     counter_u64_add_protected(c, inc);
>> -     counter_exit();
>> +     atomic_add_64((uint64_t *)zpcpu_get(c), inc);
>>  }
>>
>>  #endif       /* ! __MACHINE_COUNTER_H__ */
>> diff --git a/sys/arm64/include/counter.h b/sys/arm64/include/counter.h
>> index 9d56cce3d3d..cfa521f9b73 100644
>> --- a/sys/arm64/include/counter.h
>> +++ b/sys/arm64/include/counter.h
>> @@ -30,12 +30,10 @@
>>  #define      _MACHINE_COUNTER_H_
>>
>>  #include <sys/pcpu.h>
>> -#ifdef INVARIANTS
>> -#include <sys/proc.h>
>> -#endif
>> +#include <machine/atomic.h>
>>
>> -#define      counter_enter() critical_enter()
>> -#define      counter_exit()  critical_exit()
>> +#define      counter_enter() do {} while (0)
>> +#define      counter_exit()  do {} while (0)
>>
>>  #ifdef IN_SUBR_COUNTER_C
>>  static inline uint64_t
>> @@ -52,13 +50,12 @@ counter_u64_fetch_inline(uint64_t *p)
>>       int i;
>>
>>       r = 0;
>> -     for (i = 0; i < mp_ncpus; i++)
>> +     CPU_FOREACH(i)
>>               r += counter_u64_read_one((uint64_t *)p, i);
>>
>>       return (r);
>>  }
>>
>> -/* XXXKIB might interrupt increment */
>>  static void
>>  counter_u64_zero_one_cpu(void *arg)
>>  {
>> @@ -76,18 +73,13 @@ counter_u64_zero_inline(counter_u64_t c)
>>  }
>>  #endif
>>
>> -#define      counter_u64_add_protected(c, inc)       do {    \
>> -     CRITICAL_ASSERT(curthread);                     \
>> -     *(uint64_t *)zpcpu_get(c) += (inc);             \
>> -} while (0)
>> +#define      counter_u64_add_protected(c, inc)       counter_u64_add(c, inc)
>>
>>  static inline void
>>  counter_u64_add(counter_u64_t c, int64_t inc)
>>  {
>>
>> -     counter_enter();
>> -     counter_u64_add_protected(c, inc);
>> -     counter_exit();
>> +     atomic_add_64((uint64_t *)zpcpu_get(c), inc);
>>  }
>>
>>  #endif       /* ! _MACHINE_COUNTER_H_ */
>
> --
> Alexandre Martins
> STORMSHIELD
>