Commit daa77133 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

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: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 7c4cb50e

fs/bcachefs/time_stats.c

+16 −4
Original line number Diff line number Diff line
@@ -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)

{

	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;

}

fs/bcachefs/time_stats.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

{