diff mbox series

[4/9] sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOAD

Message ID 20180828172258.3185-5-hannes@cmpxchg.org (mailing list archive)
State New, archived
Headers show
Series psi: pressure stall information for CPU, memory, and IO v4 | expand

Commit Message

Johannes Weiner Aug. 28, 2018, 5:22 p.m. UTC
There are several definitions of those functions/macros in places that
mess with fixed-point load averages. Provide an official version.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 .../platforms/cell/cpufreq_spudemand.c        |  2 +-
 arch/powerpc/platforms/cell/spufs/sched.c     |  9 +++-----
 arch/s390/appldata/appldata_os.c              |  4 ----
 drivers/cpuidle/governors/menu.c              |  4 ----
 fs/proc/loadavg.c                             |  3 ---
 include/linux/sched/loadavg.h                 | 21 +++++++++++++++----
 kernel/debug/kdb/kdb_main.c                   |  7 +------
 kernel/sched/loadavg.c                        | 15 -------------
 8 files changed, 22 insertions(+), 43 deletions(-)

Comments

Andrew Morton Sept. 12, 2018, 11:28 p.m. UTC | #1
On Tue, 28 Aug 2018 13:22:53 -0400 Johannes Weiner <hannes@cmpxchg.org> wrote:

> There are several definitions of those functions/macros in places that
> mess with fixed-point load averages. Provide an official version.

missed blk-iolatency.c for some reason?


--- a/block/blk-iolatency.c~sched-loadavg-consolidate-load_int-load_frac-calc_load-fix
+++ a/block/blk-iolatency.c
@@ -139,7 +139,7 @@ struct iolatency_grp {
 #define BLKIOLATENCY_MAX_WIN_SIZE NSEC_PER_SEC
 /*
  * These are the constants used to fake the fixed-point moving average
- * calculation just like load average.  The call to CALC_LOAD folds
+ * calculation just like load average.  The call to calc_load() folds
  * (FIXED_1 (2048) - exp_factor) * new_sample into lat_avg.  The sampling
  * window size is bucketed to try to approximately calculate average
  * latency such that 1/exp (decay rate) is [1 min, 2.5 min) when windows
@@ -503,7 +503,7 @@ static void iolatency_check_latencies(st
 	lat_info = &parent->child_lat;
 
 	/*
-	 * CALC_LOAD takes in a number stored in fixed point representation.
+	 * calc_load() takes in a number stored in fixed point representation.
 	 * Because we are using this for IO time in ns, the values stored
 	 * are significantly larger than the FIXED_1 denominator (2048).
 	 * Therefore, rounding errors in the calculation are negligible and
@@ -512,7 +512,7 @@ static void iolatency_check_latencies(st
 	exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1,
 			div64_u64(iolat->cur_win_nsec,
 				  BLKIOLATENCY_EXP_BUCKET_SIZE));
-	CALC_LOAD(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);
+	calc_load(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);
 
 	/* Everything is ok and we don't need to adjust the scale. */
 	if (stat.mean <= iolat->min_lat_nsec &&
Johannes Weiner Sept. 13, 2018, 1:49 a.m. UTC | #2
On Wed, Sep 12, 2018 at 04:28:28PM -0700, Andrew Morton wrote:
> On Tue, 28 Aug 2018 13:22:53 -0400 Johannes Weiner <hannes@cmpxchg.org> wrote:
> 
> > There are several definitions of those functions/macros in places that
> > mess with fixed-point load averages. Provide an official version.
> 
> missed blk-iolatency.c for some reason?

Ah, that callsite came in with this merge window. Thanks for the
fixup.

> --- a/block/blk-iolatency.c~sched-loadavg-consolidate-load_int-load_frac-calc_load-fix
> +++ a/block/blk-iolatency.c
> @@ -512,7 +512,7 @@ static void iolatency_check_latencies(st
>  	exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1,
>  			div64_u64(iolat->cur_win_nsec,
>  				  BLKIOLATENCY_EXP_BUCKET_SIZE));
> -	CALC_LOAD(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);
> +	calc_load(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);

The macro used to modify the avg parameter in place, but with the
function we need an explicit assignment to update the variable:

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 335c22317757..8793f1344e11 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -512,7 +512,8 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now)
 	exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1,
 			div64_u64(iolat->cur_win_nsec,
 				  BLKIOLATENCY_EXP_BUCKET_SIZE));
-	calc_load(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);
+	iolat->lat_avg = calc_load(iolat->lat_avg,
+				   iolatency_exp_factors[exp_idx], stat.mean);
 
 	/* Everything is ok and we don't need to adjust the scale. */
 	if (stat.mean <= iolat->min_lat_nsec &&
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/cell/cpufreq_spudemand.c b/arch/powerpc/platforms/cell/cpufreq_spudemand.c
index 882944c36ef5..5d8e8b6bb1cc 100644
--- a/arch/powerpc/platforms/cell/cpufreq_spudemand.c
+++ b/arch/powerpc/platforms/cell/cpufreq_spudemand.c
@@ -49,7 +49,7 @@  static int calc_freq(struct spu_gov_info_struct *info)
 	cpu = info->policy->cpu;
 	busy_spus = atomic_read(&cbe_spu_info[cpu_to_node(cpu)].busy_spus);
 
-	CALC_LOAD(info->busy_spus, EXP, busy_spus * FIXED_1);
+	info->busy_spus = calc_load(info->busy_spus, EXP, busy_spus * FIXED_1);
 	pr_debug("cpu %d: busy_spus=%d, info->busy_spus=%ld\n",
 			cpu, busy_spus, info->busy_spus);
 
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index c9ef3c532169..9fcccb4490b9 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -987,9 +987,9 @@  static void spu_calc_load(void)
 	unsigned long active_tasks; /* fixed-point */
 
 	active_tasks = count_active_contexts() * FIXED_1;
-	CALC_LOAD(spu_avenrun[0], EXP_1, active_tasks);
-	CALC_LOAD(spu_avenrun[1], EXP_5, active_tasks);
-	CALC_LOAD(spu_avenrun[2], EXP_15, active_tasks);
+	spu_avenrun[0] = calc_load(spu_avenrun[0], EXP_1, active_tasks);
+	spu_avenrun[1] = calc_load(spu_avenrun[1], EXP_5, active_tasks);
+	spu_avenrun[2] = calc_load(spu_avenrun[2], EXP_15, active_tasks);
 }
 
 static void spusched_wake(struct timer_list *unused)
@@ -1071,9 +1071,6 @@  void spuctx_switch_state(struct spu_context *ctx,
 	}
 }
 
-#define LOAD_INT(x) ((x) >> FSHIFT)
-#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
-
 static int show_spu_loadavg(struct seq_file *s, void *private)
 {
 	int a, b, c;
diff --git a/arch/s390/appldata/appldata_os.c b/arch/s390/appldata/appldata_os.c
index 433a994b1a89..54f375627532 100644
--- a/arch/s390/appldata/appldata_os.c
+++ b/arch/s390/appldata/appldata_os.c
@@ -25,10 +25,6 @@ 
 
 #include "appldata.h"
 
-
-#define LOAD_INT(x) ((x) >> FSHIFT)
-#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
-
 /*
  * OS data
  *
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 1aef60d160eb..e508d08b7ccb 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -131,10 +131,6 @@  struct menu_device {
 	int		interval_ptr;
 };
 
-
-#define LOAD_INT(x) ((x) >> FSHIFT)
-#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
-
 static inline int get_loadavg(unsigned long load)
 {
 	return LOAD_INT(load) * 10 + LOAD_FRAC(load) / 10;
diff --git a/fs/proc/loadavg.c b/fs/proc/loadavg.c
index d06694757201..8468baee951d 100644
--- a/fs/proc/loadavg.c
+++ b/fs/proc/loadavg.c
@@ -10,9 +10,6 @@ 
 #include <linux/seqlock.h>
 #include <linux/time.h>
 
-#define LOAD_INT(x) ((x) >> FSHIFT)
-#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
-
 static int loadavg_proc_show(struct seq_file *m, void *v)
 {
 	unsigned long avnrun[3];
diff --git a/include/linux/sched/loadavg.h b/include/linux/sched/loadavg.h
index 80bc84ba5d2a..cc9cc62bb1f8 100644
--- a/include/linux/sched/loadavg.h
+++ b/include/linux/sched/loadavg.h
@@ -22,10 +22,23 @@  extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 #define EXP_5		2014		/* 1/exp(5sec/5min) */
 #define EXP_15		2037		/* 1/exp(5sec/15min) */
 
-#define CALC_LOAD(load,exp,n) \
-	load *= exp; \
-	load += n*(FIXED_1-exp); \
-	load >>= FSHIFT;
+/*
+ * a1 = a0 * e + a * (1 - e)
+ */
+static inline unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+	unsigned long newload;
+
+	newload = load * exp + active * (FIXED_1 - exp);
+	if (active >= load)
+		newload += FIXED_1-1;
+
+	return newload / FIXED_1;
+}
+
+#define LOAD_INT(x) ((x) >> FSHIFT)
+#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
 
 extern void calc_global_load(unsigned long ticks);
 
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 2ddfce8f1e8f..bb4fe4e1a601 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2556,16 +2556,11 @@  static int kdb_summary(int argc, const char **argv)
 	}
 	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
 
-	/* lifted from fs/proc/proc_misc.c::loadavg_read_proc() */
-
-#define LOAD_INT(x) ((x) >> FSHIFT)
-#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
 	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
 		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
 		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
 		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
-#undef LOAD_INT
-#undef LOAD_FRAC
+
 	/* Display in kilobytes */
 #define K(x) ((x) << (PAGE_SHIFT - 10))
 	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index a171c1258109..54fbdfb2d86c 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -91,21 +91,6 @@  long calc_load_fold_active(struct rq *this_rq, long adjust)
 	return delta;
 }
 
-/*
- * a1 = a0 * e + a * (1 - e)
- */
-static unsigned long
-calc_load(unsigned long load, unsigned long exp, unsigned long active)
-{
-	unsigned long newload;
-
-	newload = load * exp + active * (FIXED_1 - exp);
-	if (active >= load)
-		newload += FIXED_1-1;
-
-	return newload / FIXED_1;
-}
-
 #ifdef CONFIG_NO_HZ_COMMON
 /*
  * Handle NO_HZ for the global load-average.