I think there is also bug in ReplicatedPG::agent_estimate_atime_temp
I think we should change the following code:
for (map<time_t,HitSetRef>::iterator p = agent_state->hit_set_map.begin();
p != agent_state->hit_set_map.end();
++p) {
if (p->second->contains(oid)) {
if (*atime < 0)
*atime = now - p->first;
if (temp)
++(*temp);
else
return;
}
}
to something like this:
for (map<time_t,HitSetRef>::iterator p = agent_state->hit_set_map.rbegin();
p != agent_state->hit_set_map.rend();
++p) {
if (p->second->contains(oid)) {
if (*atime < 0)
*atime = now - p->first;
if (temp)
++(*temp);
else
return;
}
}
2014-10-28 9:38 GMT+08:00 池信泽 <xmdxcxz@xxxxxxxxx>:
> I think there is also bug in ReplicatedPG::agent_estimate_atime_temp
> I think we should change the following code:
> for (map<time_t,HitSetRef>::iterator p = agent_state->hit_set_map.begin();
> p != agent_state->hit_set_map.end();
> ++p) {
> if (p->second->contains(oid)) {
> if (*atime < 0)
> *atime = now - p->first;
> if (temp)
> ++(*temp);
> else
> return;
> }
> }
>
> to something like this:
>
> for (map<time_t,HitSetRef>::iterator p =
> agent_state->hit_set_map.rbegin();
> p != agent_state->hit_set_map.rend();
> ++p) {
> if (p->second->contains(oid)) {
> if (*atime < 0)
> *atime = now - p->first;
> if (temp)
> ++(*temp);
> else
> return;
> }
> }
>
> 2014-10-28 9:35 GMT+08:00 池信泽 <xmdxcxz@xxxxxxxxx>:
>>
>>
>>
>> 2014-10-28 9:24 GMT+08:00 池信泽 <xmdxcxz@xxxxxxxxx>:
>>>
>>> I think there is also bug in ReplicatedPG::agent_estimate_atime_temp
>>> I think we should change the following code:
>>> for (map<time_t,HitSetRef>::iterator p =
>>> agent_state->hit_set_map.begin();
>>> p != agent_state->hit_set_map.end();
>>> ++p) {
>>> if (p->second->contains(oid)) {
>>> if (*atime < 0)
>>> *atime = now - p->first;
>>> if (temp)
>>> ++(*temp);
>>> else
>>> return;
>>> }
>>> }
>>>
>>> to something like this:
>>>
>>> for (map<time_t,HitSetRef>::iterator p =
>>> agent_state->hit_set_map.rbegin();
>>> p != agent_state->hit_set_map.rend();
>>> ++p) {
>>> if (p->second->contains(oid)) {
>>> if (*atime < 0)
>>> *atime = now - p->first;
>>> if (temp)
>>> ++(*temp);
>>> else
>>> return;
>>> }
>>> }
>>>
>>> Because if there are mutiple time_t in agent_state for the same object,
>>> we should use the recently one.
>>>
>>> 2014-10-28 0:04 GMT+08:00 Sage Weil <sage@xxxxxxxxxxxx>:
>>>>
>>>> On Mon, 27 Oct 2014, Wang, Zhiqiang wrote:
>>>> > Hi,
>>>> >
>>>> > I agree with you this is a bug.
>>>> >
>>>> > I think we should change the following code:
>>>> >
>>>> > // KISS: if [lower,upper] spans our target effort, evict it.
>>>> > if (atime_lower >= agent_state->evict_effort)
>>>> > return false;
>>>> >
>>>> > to something like this:
>>>> >
>>>> > if (1000000 - atime_upper >= agent_state->evict_effort)
>>>> > return false;
>>>> >
>>>> > cc the ceph-devel list for comments.
>>>>
>>>> Yes, that does look backwards. Good catch! If you submit a pull request
>>>> we can get it merged and then backported.
>>>>
>>>> Thanks!
>>>> sage
>>>>
>>>>
>>>> > ________________________________________
>>>> > Date: Mon, 27 Oct 2014 10:20:01 +0800
>>>> > Subject: Cache pool bug?
>>>> > From: xmdxcxz@xxxxxxxxx
>>>> > To: wonzhq@xxxxxxxxxxx
>>>> > hi, zhiqiang?
>>>> >
>>>> > When I read the ReplicatedPG::agent_maybe_evic, I found than the
>>>> > newest object has
>>>> >
>>>> > more probability to be evicted. For Example:
>>>> >
>>>> > the object in hit_set is newest object, call
>>>> >
>>>> > the funtion agent_estimate_atime_temp(soid, &atime, NULL /*FIXME
>>>> > &temp*/); atime is 0 when return.
>>>> >
>>>> > agent_state->atime_hist.get_position_micro(atime, &atime_lower,
>>>> > &atime_upper), the atime_lower is 0 when return.
>>>> >
>>>> > // KISS: if [lower,upper] spans our target effort, evict it.
>>>> > if (atime_lower >= agent_state->evict_effort)
>>>> > return false;
>>>> >
>>>> > Above, the newest object in hit_set is evicted.
>>>> >
>>>> > Is there a bug? Or, whether I skip something?
>>>> >
>>>> >
>>>> > Thanks
>>>> > N?????r??y??????X???v???)?{.n?????z?]z????ay? ????j ??f???h????? ?w???
>>>> > ???j:+v???w???????? ????zZ+???????j"????i
>>>
>>>
>>
>
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