On Wed, Dec 4, 2013 at 4:58 PM, Jesse Gross <je...@nicira.com> wrote:
> On Wed, Dec 4, 2013 at 4:36 PM, Pravin Shelar <pshe...@nicira.com> wrote:
>> On Wed, Dec 4, 2013 at 4:23 PM, Jesse Gross <je...@nicira.com> wrote:
>>> On Wed, Dec 4, 2013 at 3:42 PM, Pravin Shelar <pshe...@nicira.com> wrote:
>>>> On Wed, Dec 4, 2013 at 1:08 PM, Jesse Gross <je...@nicira.com> wrote:
>>>>> On Fri, Nov 22, 2013 at 1:20 PM, Pravin B Shelar <pshe...@nicira.com>
>>>>> wrote:
>>>>>> diff --git a/datapath/flow.h b/datapath/flow.h
>>>>>> index 6b68cf1..2405638 100644
>>>>>> --- a/datapath/flow.h
>>>>>> +++ b/datapath/flow.h
>>>>>> -struct sw_flow_stats {
>>>>>> +struct flow_stats {
>>>>>> u64 packet_count; /* Number of packets matched. */
>>>>>> u64 byte_count; /* Number of bytes matched. */
>>>>>> unsigned long used; /* Last used time (in jiffies).
>>>>>> */
>>>>>> spinlock_t lock; /* Lock for atomic stats update.
>>>>>> */
>>>>>> +};
>>>>>> +
>>>>>> +struct sw_flow_stats {
>>>>>> __be16 tcp_flags; /* Union of seen TCP flags. */
>>>>>> -} ____cacheline_aligned_in_smp;
>>>>>> + bool is_percpu;
>>>>>> + union {
>>>>>> + struct flow_stats *stat;
>>>>>> + struct flow_stats __percpu *cpu_stats;
>>>>>> + };
>>>>>> +};
>>>>>
>>>>> I wonder if it makes sense to directly put struct flow_stats in the
>>>>> union for the non-percpu case and avoid an extra indirection there.
>>>>>
>>>> This saves some memory, thats why I done it this way.
>>>
>>> It does in the percpu case, although we're essentially already betting
>>> that there are relatively few flows there. I think it saves some
>>> memory in the non-percpu case though.
>>
>> I also wanted to make better use of cache-line (as it is accessed in
>> hot-path) for per cpu case.
>
> Isn't this on the end of a struct that is just malloc'ed and therefore
> not necessarily contiguous with anything of interest?
>
I have another patch which tries to optimize all datapath structures.
I have posted first version. I am planning on fixing it according to
comments I got.
> I'm not trying to convince you to change, just trying to better
> understand the rationale.
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
