From: Dan Carpenter <dan.carpenter@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
Yafang Shao <laoar.shao@gmail.com>, Mel Gorman <mgorman@suse.de>,
x86@kernel.org
Subject: Re: [tip: sched/core] sched: Make struct sched_statistics independent of fair sched class
Date: Tue, 21 Sep 2021 10:40:42 +0300 [thread overview]
Message-ID: <20210921074042.GU2116@kadam> (raw)
In-Reply-To: <YUmG8+96zgScrfqm@hirez.programming.kicks-ass.net>
On Tue, Sep 21, 2021 at 09:17:07AM +0200, Peter Zijlstra wrote:
> On Tue, Sep 21, 2021 at 09:17:27AM +0300, Dan Carpenter wrote:
> > On Thu, Sep 16, 2021 at 11:59:30AM -0000, tip-bot2 for Yafang Shao wrote:
> > > @@ -11424,7 +11441,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
> > > if (!cfs_rq)
> > > goto err;
> > >
> > > - se = kzalloc_node(sizeof(struct sched_entity),
> > > + se = kzalloc_node(sizeof(struct sched_entity_stats),
> >
> > This wasn't there in the original patch and it causes a Smatch warning
>
> What original patch? It's part of the v4 posting.
>
> > because "se" is declared as a "sched_entity" but it's allocating a
> > larger "sched_entity_stats" which contains a sched_entity.
>
> Yep, on purpose.
>
> > To me, ideally, we would update the type of se.
>
> That's a lot of churn for very little gain. I can rewrite it like:
>
> struct sched_entity_stats *ses = kzalloc_node(sizeof(*ses),...);
> se = &ses->se;
>
> If that makes smatch happy. It's the exact same thing tho because we
> force ses->se to be at 0 offset.
I mean, I understood what the allocation was doing and that this was a
way to avoid churn. But it's pretty confusing, because every "se" is
really an "ses" now right?
Anyway, just leave it. It's fine.
regards,
dan carpenter
next prev parent reply other threads:[~2021-09-21 7:41 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-05 14:35 [PATCH v4 0/8] sched: support schedstats for RT sched class Yafang Shao
2021-09-05 14:35 ` [PATCH v4 1/8] sched, fair: use __schedstat_set() in set_next_entity() Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched/fair: Use " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 2/8] sched: make struct sched_statistics independent of fair sched class Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched: Make " tip-bot2 for Yafang Shao
2021-09-21 6:17 ` Dan Carpenter
2021-09-21 7:17 ` Peter Zijlstra
2021-09-21 7:40 ` Dan Carpenter [this message]
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 3/8] sched: make schedstats helpers " Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched: Make " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 4/8] sched: introduce task block time in schedstats Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched: Introduce " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 5/8] sched, rt: support sched_stat_runtime tracepoint for RT sched class Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched/rt: Support " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 6/8] sched, rt: support schedstats " Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched/rt: Support " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 7/8] sched, dl: support sched_stat_runtime tracepoint for deadline " Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched/dl: Support " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-05 14:35 ` [PATCH v4 8/8] sched, dl: support schedstats " Yafang Shao
2021-09-16 11:59 ` [tip: sched/core] sched/dl: Support " tip-bot2 for Yafang Shao
2021-10-05 14:12 ` tip-bot2 for Yafang Shao
2021-09-10 17:00 ` [PATCH v4 0/8] sched: support schedstats for RT " Peter Zijlstra
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