Messages in this thread | | | Date | Tue, 24 Nov 2020 11:40:42 +0000 | From | Mel Gorman <> | Subject | Re: [RFC PATCH v2 3/5] sched: make schedstats helper independent of cfs_rq |
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On Mon, Nov 23, 2020 at 08:58:06PM +0800, Yafang Shao wrote: > The 'cfs_rq' in these helpers > update_stats_{wait_start, wait_end, enqueue_sleeper} is only used to get > the rq_clock, so we can pass the rq directly. Then these helpers can be > used by all sched class after being moved into stats.h. > > After that change, the size of vmlinux is increased around 824Bytes. > w/o this patch, with this patch > Size of vmlinux: 78443832 78444656 > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
The inline helpers are quite large. When I was suggesting that the overhead was minimal, what I expected what that the inline functions would be a schedstat_enabled() followed by a real function call. It would introduce a small additional overhead when schedstats are enabled but avoid vmlinux growing too large
e.g.
static inline void update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { if (!schedstat_enabled()) return;
__update_stats_wait_start(cfs_rq, se); }
where __update_stats_wait_start then lives in kernel/sched/stats.c
-- Mel Gorman SUSE Labs
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