在 2022/8/19 上午10:28, SeongJae Park 写道:
Hi Xin,
在 2022/8/19 上午1:11, SeongJae Park 写道:
Hi Xin,
On Thu, 18 Aug 2022 18:57:31 +0800 Xin Hao <xhao@xxxxxxxxxxxxxxxxx> wrote:
In damon_lru_sort_apply_parameters(), if "monitor_region_start"
and "monitor_region_end" is not a valid physical address range,
There no need to run the remainder codes in it.
The function, 'damon_lru_sort_apply_parameters()', checks validity of
parameters and construct the DAMON context one by one. For example,
'damon_set_attrs()' returns an error if the parameters are invalid. So the
intended flow is,
1. check DAMON attributes parameters,
2. apply DAMON attributes parameters,
3. check scheme parameters,
4. apply scheme parameters,
5. check target region parameters, and
6. apply target region parameters.
Therefore what this patch does is making the target regions validity check to
be done earlier than validity checks of other parameters. There is no special
reason to check the region earlier than others. Also, this change makes the
flow of the function a little bit weird in my humble opinion, as the flow will
be
1. check target region parameters,
2. check DAMON attributes parameters,
3. apply DAMON attributes parameters,
4. check scheme parameters,
5. apply scheme parameters, and
6. apply target region parameters.
Ok, understand what you mean, my fix looks ugly, buy any apply above
are not not necessary if one of them checks failed, why not check all
fisrt and then apply them, like this:
1. check target region parameters,
2. check DAMON attributes parameters,
3. check scheme parameters,
The parameter values could be changed by users after the check, so we should
cache those somewhere anyway. In other words, we cache those in the DAMON
context. Therefore I think the above works were not totally waste of the time.
Also, because the parameters applying functions like 'damon_set_attrs()' does
the check and applying of the parameters together, I feel like current flow is
natural.
Ok, Thank you for your detailed explain, just keep it. but there still
a problem in damon_lru_sort_apply_parameters
if (!monitor_region_start && !monitor_region_end &&
!get_monitoring_region(&monitor_region_start,
&monitor_region_end))
if (!monitor_region_start || !monitor_region_end ||
!get_monitoring_region(&monitor_region_start,
&monitor_region_end))
the '&&' should fix to '||', anyone checks fail, it should return ?
