From: Kent Overstreet <[email protected]> We have 4 spare bytes next to the spinlock, no need for bit stuffing
Signed-off-by: Kent Overstreet <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]> --- include/linux/time_stats.h | 19 +++++-------------- lib/time_stats.c | 4 ++-- 2 files changed, 7 insertions(+), 16 deletions(-) diff --git a/include/linux/time_stats.h b/include/linux/time_stats.h index 4e1f5485ed039..6df2b34aa274b 100644 --- a/include/linux/time_stats.h +++ b/include/linux/time_stats.h @@ -68,6 +68,7 @@ struct time_stat_buffer { struct time_stats { spinlock_t lock; + bool have_quantiles; /* all fields are in nanoseconds */ u64 min_duration; u64 max_duration; @@ -87,12 +88,6 @@ struct time_stats { struct mean_and_variance_weighted freq_stats_weighted; struct time_stat_buffer __percpu *buffer; -/* - * Is this really a struct time_stats_quantiled? Hide this flag in the least - * significant bit of the start time to avoid blowing up the structure size. - */ -#define TIME_STATS_HAVE_QUANTILES (1ULL << 0) - u64 start_time; }; @@ -103,13 +98,9 @@ struct time_stats_quantiles { static inline struct quantiles *time_stats_to_quantiles(struct time_stats *stats) { - struct time_stats_quantiles *statq; - - if (!(stats->start_time & TIME_STATS_HAVE_QUANTILES)) - return NULL; - - statq = container_of(stats, struct time_stats_quantiles, stats); - return &statq->quantiles; + return stats->have_quantiles + ? &container_of(stats, struct time_stats_quantiles, stats)->quantiles + : NULL; } void __time_stats_clear_buffer(struct time_stats *, struct time_stat_buffer *); @@ -169,7 +160,7 @@ static inline void time_stats_quantiles_exit(struct time_stats_quantiles *statq) static inline void time_stats_quantiles_init(struct time_stats_quantiles *statq) { time_stats_init(&statq->stats); - statq->stats.start_time |= TIME_STATS_HAVE_QUANTILES; + statq->stats.have_quantiles = true; memset(&statq->quantiles, 0, sizeof(statq->quantiles)); } diff --git a/lib/time_stats.c b/lib/time_stats.c index c0f209dd9f6dd..0b90c80cba9f1 100644 --- a/lib/time_stats.c +++ b/lib/time_stats.c @@ -164,7 +164,7 @@ static void seq_buf_time_units_aligned(struct seq_buf *out, u64 ns) static inline u64 time_stats_lifetime(const struct time_stats *stats) { - return local_clock() - (stats->start_time & ~TIME_STATS_HAVE_QUANTILES); + return local_clock() - stats->start_time; } void time_stats_to_seq_buf(struct seq_buf *out, struct time_stats *stats, @@ -364,7 +364,7 @@ void time_stats_init(struct time_stats *stats) memset(stats, 0, sizeof(*stats)); stats->min_duration = U64_MAX; stats->min_freq = U64_MAX; - stats->start_time = local_clock() & ~TIME_STATS_HAVE_QUANTILES; + stats->start_time = local_clock(); spin_lock_init(&stats->lock); } EXPORT_SYMBOL_GPL(time_stats_init);
