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| author |   Kent Overstreet <kent.overstreet@linux.dev> | 2025-03-25 10:52:00 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2025-03-28 22:31:47 -0400 |
| commit | daa771332e1e074c22b706e981de28d384577268 (patch) | |
| tree | c95e3e7038b505ba7838ffc921ed6b8525b8abc4 | |
| parent | bcachefs: Fix bch2_fs_get_tree() error path (diff) | |
| download | wireguard-linux-daa771332e1e074c22b706e981de28d384577268.tar.xz wireguard-linux-daa771332e1e074c22b706e981de28d384577268.zip | |
bcachefs: bch2_time_stats_init_no_pcpu()
Add a mode to disable automatic switching to percpu mode, useful when a
time_stats will only be used by one thread and we don't want to have to
flush the percpu buffers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/time_stats.c | 20 | ||||
| -rw-r--r-- | fs/bcachefs/time_stats.h | 1 |
2 files changed, 17 insertions, 4 deletions
diff --git a/fs/bcachefs/time_stats.c b/fs/bcachefs/time_stats.c index 3fe82757f93a..2c34fe4be912 100644 --- a/fs/bcachefs/time_stats.c +++ b/fs/bcachefs/time_stats.c @@ -10,6 +10,9 @@ #include "eytzinger.h" #include "time_stats.h" +/* disable automatic switching to percpu mode */ +#define TIME_STATS_NONPCPU ((unsigned long) 1) + static const struct time_unit time_units[] = { { "ns", 1 }, { "us", NSEC_PER_USEC }, @@ -123,11 +126,12 @@ void __bch2_time_stats_update(struct bch2_time_stats *stats, u64 start, u64 end) { unsigned long flags; - if (!stats->buffer) { + if ((unsigned long) stats->buffer <= TIME_STATS_NONPCPU) { spin_lock_irqsave(&stats->lock, flags); time_stats_update_one(stats, start, end); - if (mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT) < 32 && + if (!stats->buffer && + mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT) < 32 && stats->duration_stats.n > 1024) stats->buffer = alloc_percpu_gfp(struct time_stat_buffer, @@ -157,7 +161,7 @@ void bch2_time_stats_reset(struct bch2_time_stats *stats) unsigned offset = offsetof(struct bch2_time_stats, min_duration); memset((void *) stats + offset, 0, sizeof(*stats) - offset); - if (stats->buffer) { + if ((unsigned long) stats->buffer > TIME_STATS_NONPCPU) { int cpu; for_each_possible_cpu(cpu) per_cpu_ptr(stats->buffer, cpu)->nr = 0; @@ -167,7 +171,9 @@ void bch2_time_stats_reset(struct bch2_time_stats *stats) void bch2_time_stats_exit(struct bch2_time_stats *stats) { - free_percpu(stats->buffer); + if ((unsigned long) stats->buffer > TIME_STATS_NONPCPU) + free_percpu(stats->buffer); + stats->buffer = NULL; } void bch2_time_stats_init(struct bch2_time_stats *stats) @@ -177,3 +183,9 @@ void bch2_time_stats_init(struct bch2_time_stats *stats) stats->min_freq = U64_MAX; spin_lock_init(&stats->lock); } + +void bch2_time_stats_init_no_pcpu(struct bch2_time_stats *stats) +{ + bch2_time_stats_init(stats); + stats->buffer = (struct time_stat_buffer __percpu *) TIME_STATS_NONPCPU; +} diff --git a/fs/bcachefs/time_stats.h b/fs/bcachefs/time_stats.h index dc6493f7bbab..eddb0985bab4 100644 --- a/fs/bcachefs/time_stats.h +++ b/fs/bcachefs/time_stats.h @@ -145,6 +145,7 @@ static inline bool track_event_change(struct bch2_time_stats *stats, bool v) void bch2_time_stats_reset(struct bch2_time_stats *); void bch2_time_stats_exit(struct bch2_time_stats *); void bch2_time_stats_init(struct bch2_time_stats *); +void bch2_time_stats_init_no_pcpu(struct bch2_time_stats *); static inline void bch2_time_stats_quantiles_exit(struct bch2_time_stats_quantiles *statq) { |