On Mon, Dec 14, 2015 at 10:35 AM, Paolo Bonzini <pbonz...@redhat.com> wrote:
>
>
> On 14/12/2015 09:41, Alvise Rigo wrote:
>> +static inline void excl_history_put_addr(CPUState *cpu, hwaddr addr)
>> +{
>> + /* Avoid some overhead if the address we are about to put is equal to
>> + * the last one */
>> + if (cpu->excl_protected_addr[cpu->excl_protected_last] !=
>> + (addr & TARGET_PAGE_MASK)) {
>> + cpu->excl_protected_last = (cpu->excl_protected_last + 1) %
>> + EXCLUSIVE_HISTORY_LEN;
>
> Either use "&" here...
>
>> + /* Unset EXCL bit of the oldest entry */
>> + if (cpu->excl_protected_addr[cpu->excl_protected_last] !=
>> + EXCLUSIVE_RESET_ADDR) {
>> + cpu_physical_memory_unset_excl(
>> + cpu->excl_protected_addr[cpu->excl_protected_last],
>> + cpu->cpu_index);
>> + }
>> +
>> + /* Add a new address, overwriting the oldest one */
>> + cpu->excl_protected_addr[cpu->excl_protected_last] =
>> + addr & TARGET_PAGE_MASK;
>> + }
>> +}
>> +
>> #define MMUSUFFIX _mmu
>>
>> /* Generates LoadLink/StoreConditional helpers in softmmu_template.h */
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index 9e409ce..5f65ebf 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -217,6 +217,7 @@ struct kvm_run;
>>
>> /* Atomic insn translation TLB support. */
>> #define EXCLUSIVE_RESET_ADDR ULLONG_MAX
>> +#define EXCLUSIVE_HISTORY_LEN 8
>>
>> /**
>> * CPUState:
>> @@ -343,6 +344,8 @@ struct CPUState {
>> * The address is set to EXCLUSIVE_RESET_ADDR if the vCPU is not.
>> * in the middle of a LL/SC. */
>> struct Range excl_protected_range;
>> + hwaddr excl_protected_addr[EXCLUSIVE_HISTORY_LEN];
>> + int excl_protected_last;
>
> ... or make this an "unsigned int". Otherwise the code will contain an
> actual (and slow) modulo operation.
Absolutely true.
Thank you,
alvise
>
> Paolo
>
>> /* Used to carry the SC result but also to flag a normal (legacy)
>> * store access made by a stcond (see softmmu_template.h). */
>> int excl_succeeded;
