Re: [PATCH V1 1/2] mm/damon/sysfs: avoid call damon_target_has_pid() repeatedly

[haoxin]

在 2022/9/16 下午4:42, SeongJae Park 写道:
> On Thu, 15 Sep 2022 22:22:36 +0800 Xin Hao <xhao@xxxxxxxxxxxxxxxxx> wrote:
>
> > In damon_sysfs_destroy_targets(), we call damon_target_has_pid() to
> > check whether the 'ctx' include a valid pid, but there no need to call
> > damon_target_has_pid() to check repeatedly, just need call it once.
> Good eyes, nice finding!
>
> > Signed-off-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
> > ---
> >   mm/damon/sysfs.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
> > index 1fa0023f136e..966ea7892ccf 100644
> > --- a/mm/damon/sysfs.c
> > +++ b/mm/damon/sysfs.c
> > @@ -2143,9 +2143,13 @@ static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
> >   static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
> >   {
> >   	struct damon_target *t, *next;
> > +	bool has_pid = false;
> > +
> > +	if (damon_target_has_pid(ctx))
> > +		has_pid = true;
> How about doing more simple and short like below?
>
>      bool has_pid = damon_target_has_pid(ctx)
Yes, Do like this, make code look more clean. but this patch has been 
merged into,  i send a new one to fix it ?
> Other than this,
>
> Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
>
>
> Thanks,
> SJ
>
> >   	damon_for_each_target_safe(t, next, ctx) {
> > -		if (damon_target_has_pid(ctx))
> > +		if (has_pid)
> >   			put_pid(t->pid);
> >   		damon_destroy_target(t);
> >   	}
> > --
> > 2.31.0