* [RFC PATCH 1/3] sched/deadline: refactor cpu heap code
2016-08-14 14:27 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Tommaso Cucinotta
@ 2016-08-14 14:27 ` Tommaso Cucinotta
2016-09-05 11:53 ` [tip:sched/core] sched/deadline: Refactor CPU " tip-bot for Tommaso Cucinotta
2016-08-14 14:27 ` [RFC PATCH 2/3] sched/deadline: make cpu heap faster avoiding real swaps on heapify Tommaso Cucinotta
` (2 subsequent siblings)
3 siblings, 1 reply; 8+ messages in thread
From: Tommaso Cucinotta @ 2016-08-14 14:27 UTC (permalink / raw)
To: Luca Abeni, Juri Lelli, Peter Zijlstra, Ingo Molnar
Cc: linux-kernel, linux-dl, Tommaso Cucinotta, Juri Lelli
1. heapify up factored out in new dedicated function heapify_up()
(avoids repetition of same code)
2. call to cpudl_change_key() replaced with heapify_up() when
cpudl_set actually inserts a new node in the heap
3. cpudl_change_key() replaced with heapify() that heapifies up
or down as needed.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
---
kernel/sched/cpudeadline.c | 50 +++++++++++++++++++++-------------------------
1 file changed, 23 insertions(+), 27 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index d418449..0acb0d4 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -41,7 +41,7 @@ static void cpudl_exchange(struct cpudl *cp, int a, int b)
swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
}
-static void cpudl_heapify(struct cpudl *cp, int idx)
+static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
int l, r, largest;
@@ -66,23 +66,24 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
}
}
-static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
+static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
- WARN_ON(idx == IDX_INVALID || !cpu_present(idx));
-
- if (dl_time_before(new_dl, cp->elements[idx].dl)) {
- cp->elements[idx].dl = new_dl;
- cpudl_heapify(cp, idx);
- } else {
- cp->elements[idx].dl = new_dl;
- while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
- cp->elements[idx].dl)) {
- cpudl_exchange(cp, idx, parent(idx));
- idx = parent(idx);
- }
+ while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
+ cp->elements[idx].dl)) {
+ cpudl_exchange(cp, idx, parent(idx));
+ idx = parent(idx);
}
}
+static void cpudl_heapify(struct cpudl *cp, int idx)
+{
+ if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
+ cp->elements[idx].dl))
+ cpudl_heapify_up(cp, idx);
+ else
+ cpudl_heapify_down(cp, idx);
+}
+
static inline int cpudl_maximum(struct cpudl *cp)
{
return cp->elements[0].cpu;
@@ -154,27 +155,22 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cp->size--;
cp->elements[new_cpu].idx = old_idx;
cp->elements[cpu].idx = IDX_INVALID;
- while (old_idx > 0 && dl_time_before(
- cp->elements[parent(old_idx)].dl,
- cp->elements[old_idx].dl)) {
- cpudl_exchange(cp, old_idx, parent(old_idx));
- old_idx = parent(old_idx);
- }
+ cpudl_heapify(cp, old_idx);
cpumask_set_cpu(cpu, cp->free_cpus);
- cpudl_heapify(cp, old_idx);
goto out;
}
if (old_idx == IDX_INVALID) {
- cp->size++;
- cp->elements[cp->size - 1].dl = dl;
- cp->elements[cp->size - 1].cpu = cpu;
- cp->elements[cpu].idx = cp->size - 1;
- cpudl_change_key(cp, cp->size - 1, dl);
+ int new_idx = cp->size++;
+ cp->elements[new_idx].dl = dl;
+ cp->elements[new_idx].cpu = cpu;
+ cp->elements[cpu].idx = new_idx;
+ cpudl_heapify_up(cp, new_idx);
cpumask_clear_cpu(cpu, cp->free_cpus);
} else {
- cpudl_change_key(cp, old_idx, dl);
+ cp->elements[old_idx].dl = dl;
+ cpudl_heapify(cp, old_idx);
}
out:
--
2.7.4
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:sched/core] sched/deadline: Refactor CPU heap code
2016-08-14 14:27 ` [RFC PATCH 1/3] sched/deadline: refactor cpu heap code Tommaso Cucinotta
@ 2016-09-05 11:53 ` tip-bot for Tommaso Cucinotta
0 siblings, 0 replies; 8+ messages in thread
From: tip-bot for Tommaso Cucinotta @ 2016-09-05 11:53 UTC (permalink / raw)
To: linux-tip-commits
Cc: juri.lelli, linux-kernel, luca.abeni, torvalds, peterz, hpa,
mingo, juri.lelli, tglx, tommaso.cucinotta
Commit-ID: 126b3b6842cc848fc9880e7816e0a8d743be51f1
Gitweb: http://git.kernel.org/tip/126b3b6842cc848fc9880e7816e0a8d743be51f1
Author: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
AuthorDate: Sun, 14 Aug 2016 16:27:06 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 5 Sep 2016 13:29:42 +0200
sched/deadline: Refactor CPU heap code
1. heapify up factored out in new dedicated function heapify_up()
(avoids repetition of same code)
2. call to cpudl_change_key() replaced with heapify_up() when
cpudl_set actually inserts a new node in the heap
3. cpudl_change_key() replaced with heapify() that heapifies up
or down as needed.
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-dl@retis.sssup.it
Link: http://lkml.kernel.org/r/1471184828-12644-2-git-send-email-tommaso.cucinotta@sssup.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/cpudeadline.c | 50 +++++++++++++++++++++-------------------------
1 file changed, 23 insertions(+), 27 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index d418449..0acb0d4 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -41,7 +41,7 @@ static void cpudl_exchange(struct cpudl *cp, int a, int b)
swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
}
-static void cpudl_heapify(struct cpudl *cp, int idx)
+static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
int l, r, largest;
@@ -66,23 +66,24 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
}
}
-static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
+static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
- WARN_ON(idx == IDX_INVALID || !cpu_present(idx));
-
- if (dl_time_before(new_dl, cp->elements[idx].dl)) {
- cp->elements[idx].dl = new_dl;
- cpudl_heapify(cp, idx);
- } else {
- cp->elements[idx].dl = new_dl;
- while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
- cp->elements[idx].dl)) {
- cpudl_exchange(cp, idx, parent(idx));
- idx = parent(idx);
- }
+ while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
+ cp->elements[idx].dl)) {
+ cpudl_exchange(cp, idx, parent(idx));
+ idx = parent(idx);
}
}
+static void cpudl_heapify(struct cpudl *cp, int idx)
+{
+ if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
+ cp->elements[idx].dl))
+ cpudl_heapify_up(cp, idx);
+ else
+ cpudl_heapify_down(cp, idx);
+}
+
static inline int cpudl_maximum(struct cpudl *cp)
{
return cp->elements[0].cpu;
@@ -154,27 +155,22 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cp->size--;
cp->elements[new_cpu].idx = old_idx;
cp->elements[cpu].idx = IDX_INVALID;
- while (old_idx > 0 && dl_time_before(
- cp->elements[parent(old_idx)].dl,
- cp->elements[old_idx].dl)) {
- cpudl_exchange(cp, old_idx, parent(old_idx));
- old_idx = parent(old_idx);
- }
+ cpudl_heapify(cp, old_idx);
cpumask_set_cpu(cpu, cp->free_cpus);
- cpudl_heapify(cp, old_idx);
goto out;
}
if (old_idx == IDX_INVALID) {
- cp->size++;
- cp->elements[cp->size - 1].dl = dl;
- cp->elements[cp->size - 1].cpu = cpu;
- cp->elements[cpu].idx = cp->size - 1;
- cpudl_change_key(cp, cp->size - 1, dl);
+ int new_idx = cp->size++;
+ cp->elements[new_idx].dl = dl;
+ cp->elements[new_idx].cpu = cpu;
+ cp->elements[cpu].idx = new_idx;
+ cpudl_heapify_up(cp, new_idx);
cpumask_clear_cpu(cpu, cp->free_cpus);
} else {
- cpudl_change_key(cp, old_idx, dl);
+ cp->elements[old_idx].dl = dl;
+ cpudl_heapify(cp, old_idx);
}
out:
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RFC PATCH 2/3] sched/deadline: make cpu heap faster avoiding real swaps on heapify
2016-08-14 14:27 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Tommaso Cucinotta
2016-08-14 14:27 ` [RFC PATCH 1/3] sched/deadline: refactor cpu heap code Tommaso Cucinotta
@ 2016-08-14 14:27 ` Tommaso Cucinotta
2016-09-05 11:54 ` [tip:sched/core] sched/deadline: Make CPU " tip-bot for Tommaso Cucinotta
2016-08-14 14:27 ` [RFC PATCH 3/3] sched/deadline: split cpudl_set() into cpudl_set() and cpudl_clear() Tommaso Cucinotta
2016-08-19 12:58 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Peter Zijlstra
3 siblings, 1 reply; 8+ messages in thread
From: Tommaso Cucinotta @ 2016-08-14 14:27 UTC (permalink / raw)
To: Luca Abeni, Juri Lelli, Peter Zijlstra, Ingo Molnar
Cc: linux-kernel, linux-dl, Tommaso Cucinotta, Juri Lelli
This change goes from heapify() ops done by swapping with parent/child
so that the item to fix moves along, to heapify() ops done by just
pulling the parent/child chain by 1 pos, then storing the item to fix
just at the end. On a non-trivial heapify(), this performs roughly half
stores wrt swaps.
This has been measured to achieve up to 10% of speed-up for cpudl_set()
calls, with a randomly generated workload of 1K,10K,100K random heap
insertions and deletions (75% cpudl_set() calls with is_valid=1 and
25% with is_valid=0), and randomly generated cpu IDs, with up to 256
CPUs, as measured on an Intel Core2 Duo.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
---
kernel/sched/cpudeadline.c | 66 +++++++++++++++++++++++++++++++---------------
1 file changed, 45 insertions(+), 21 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0acb0d4..0ace75a 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -31,48 +31,72 @@ static inline int right_child(int i)
return (i << 1) + 2;
}
-static void cpudl_exchange(struct cpudl *cp, int a, int b)
-{
- int cpu_a = cp->elements[a].cpu, cpu_b = cp->elements[b].cpu;
-
- swap(cp->elements[a].cpu, cp->elements[b].cpu);
- swap(cp->elements[a].dl , cp->elements[b].dl );
-
- swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
-}
-
static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
int l, r, largest;
+ int orig_cpu = cp->elements[idx].cpu;
+ u64 orig_dl = cp->elements[idx].dl;
+
+ if (left_child(idx) >= cp->size)
+ return;
+
/* adapted from lib/prio_heap.c */
while(1) {
+ u64 largest_dl;
l = left_child(idx);
r = right_child(idx);
largest = idx;
+ largest_dl = orig_dl;
- if ((l < cp->size) && dl_time_before(cp->elements[idx].dl,
- cp->elements[l].dl))
+ if ((l < cp->size) && dl_time_before(orig_dl,
+ cp->elements[l].dl)) {
largest = l;
- if ((r < cp->size) && dl_time_before(cp->elements[largest].dl,
- cp->elements[r].dl))
+ largest_dl = cp->elements[l].dl;
+ }
+ if ((r < cp->size) && dl_time_before(largest_dl,
+ cp->elements[r].dl))
largest = r;
+
if (largest == idx)
break;
- /* Push idx down the heap one level and bump one up */
- cpudl_exchange(cp, largest, idx);
+ /* pull largest child onto idx */
+ cp->elements[idx].cpu = cp->elements[largest].cpu;
+ cp->elements[idx].dl = cp->elements[largest].dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
idx = largest;
}
+ /* actual push down of saved original values orig_* */
+ cp->elements[idx].cpu = orig_cpu;
+ cp->elements[idx].dl = orig_dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
- while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
- cp->elements[idx].dl)) {
- cpudl_exchange(cp, idx, parent(idx));
- idx = parent(idx);
- }
+ int p;
+
+ int orig_cpu = cp->elements[idx].cpu;
+ u64 orig_dl = cp->elements[idx].dl;
+
+ if (idx == 0)
+ return;
+
+ do {
+ p = parent(idx);
+ if (dl_time_before(orig_dl, cp->elements[p].dl))
+ break;
+ /* pull parent onto idx */
+ cp->elements[idx].cpu = cp->elements[p].cpu;
+ cp->elements[idx].dl = cp->elements[p].dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
+ idx = p;
+ } while (idx != 0);
+ /* actual push up of saved original values orig_* */
+ cp->elements[idx].cpu = orig_cpu;
+ cp->elements[idx].dl = orig_dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify(struct cpudl *cp, int idx)
--
2.7.4
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:sched/core] sched/deadline: Make CPU heap faster avoiding real swaps on heapify
2016-08-14 14:27 ` [RFC PATCH 2/3] sched/deadline: make cpu heap faster avoiding real swaps on heapify Tommaso Cucinotta
@ 2016-09-05 11:54 ` tip-bot for Tommaso Cucinotta
0 siblings, 0 replies; 8+ messages in thread
From: tip-bot for Tommaso Cucinotta @ 2016-09-05 11:54 UTC (permalink / raw)
To: linux-tip-commits
Cc: tommaso.cucinotta, hpa, peterz, torvalds, linux-kernel,
juri.lelli, mingo, luca.abeni, juri.lelli, tglx
Commit-ID: 8e1bc301aaf9f9a2d731bf8d50d549ac2dcfdab2
Gitweb: http://git.kernel.org/tip/8e1bc301aaf9f9a2d731bf8d50d549ac2dcfdab2
Author: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
AuthorDate: Sun, 14 Aug 2016 16:27:07 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 5 Sep 2016 13:29:43 +0200
sched/deadline: Make CPU heap faster avoiding real swaps on heapify
This change goes from heapify() ops done by swapping with parent/child
so that the item to fix moves along, to heapify() ops done by just
pulling the parent/child chain by 1 pos, then storing the item to fix
just at the end. On a non-trivial heapify(), this performs roughly half
stores wrt swaps.
This has been measured to achieve up to 10% of speed-up for cpudl_set()
calls, with a randomly generated workload of 1K,10K,100K random heap
insertions and deletions (75% cpudl_set() calls with is_valid=1 and
25% with is_valid=0), and randomly generated cpu IDs, with up to 256
CPUs, as measured on an Intel Core2 Duo.
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-dl@retis.sssup.it
Link: http://lkml.kernel.org/r/1471184828-12644-3-git-send-email-tommaso.cucinotta@sssup.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/cpudeadline.c | 66 +++++++++++++++++++++++++++++++---------------
1 file changed, 45 insertions(+), 21 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0acb0d4..0ace75a 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -31,48 +31,72 @@ static inline int right_child(int i)
return (i << 1) + 2;
}
-static void cpudl_exchange(struct cpudl *cp, int a, int b)
-{
- int cpu_a = cp->elements[a].cpu, cpu_b = cp->elements[b].cpu;
-
- swap(cp->elements[a].cpu, cp->elements[b].cpu);
- swap(cp->elements[a].dl , cp->elements[b].dl );
-
- swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);
-}
-
static void cpudl_heapify_down(struct cpudl *cp, int idx)
{
int l, r, largest;
+ int orig_cpu = cp->elements[idx].cpu;
+ u64 orig_dl = cp->elements[idx].dl;
+
+ if (left_child(idx) >= cp->size)
+ return;
+
/* adapted from lib/prio_heap.c */
while(1) {
+ u64 largest_dl;
l = left_child(idx);
r = right_child(idx);
largest = idx;
+ largest_dl = orig_dl;
- if ((l < cp->size) && dl_time_before(cp->elements[idx].dl,
- cp->elements[l].dl))
+ if ((l < cp->size) && dl_time_before(orig_dl,
+ cp->elements[l].dl)) {
largest = l;
- if ((r < cp->size) && dl_time_before(cp->elements[largest].dl,
- cp->elements[r].dl))
+ largest_dl = cp->elements[l].dl;
+ }
+ if ((r < cp->size) && dl_time_before(largest_dl,
+ cp->elements[r].dl))
largest = r;
+
if (largest == idx)
break;
- /* Push idx down the heap one level and bump one up */
- cpudl_exchange(cp, largest, idx);
+ /* pull largest child onto idx */
+ cp->elements[idx].cpu = cp->elements[largest].cpu;
+ cp->elements[idx].dl = cp->elements[largest].dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
idx = largest;
}
+ /* actual push down of saved original values orig_* */
+ cp->elements[idx].cpu = orig_cpu;
+ cp->elements[idx].dl = orig_dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify_up(struct cpudl *cp, int idx)
{
- while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,
- cp->elements[idx].dl)) {
- cpudl_exchange(cp, idx, parent(idx));
- idx = parent(idx);
- }
+ int p;
+
+ int orig_cpu = cp->elements[idx].cpu;
+ u64 orig_dl = cp->elements[idx].dl;
+
+ if (idx == 0)
+ return;
+
+ do {
+ p = parent(idx);
+ if (dl_time_before(orig_dl, cp->elements[p].dl))
+ break;
+ /* pull parent onto idx */
+ cp->elements[idx].cpu = cp->elements[p].cpu;
+ cp->elements[idx].dl = cp->elements[p].dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
+ idx = p;
+ } while (idx != 0);
+ /* actual push up of saved original values orig_* */
+ cp->elements[idx].cpu = orig_cpu;
+ cp->elements[idx].dl = orig_dl;
+ cp->elements[cp->elements[idx].cpu].idx = idx;
}
static void cpudl_heapify(struct cpudl *cp, int idx)
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [RFC PATCH 3/3] sched/deadline: split cpudl_set() into cpudl_set() and cpudl_clear()
2016-08-14 14:27 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Tommaso Cucinotta
2016-08-14 14:27 ` [RFC PATCH 1/3] sched/deadline: refactor cpu heap code Tommaso Cucinotta
2016-08-14 14:27 ` [RFC PATCH 2/3] sched/deadline: make cpu heap faster avoiding real swaps on heapify Tommaso Cucinotta
@ 2016-08-14 14:27 ` Tommaso Cucinotta
2016-09-05 11:54 ` [tip:sched/core] sched/deadline: Split " tip-bot for Tommaso Cucinotta
2016-08-19 12:58 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Peter Zijlstra
3 siblings, 1 reply; 8+ messages in thread
From: Tommaso Cucinotta @ 2016-08-14 14:27 UTC (permalink / raw)
To: Luca Abeni, Juri Lelli, Peter Zijlstra, Ingo Molnar
Cc: linux-kernel, linux-dl, Tommaso Cucinotta, Juri Lelli
These 2 exercise independent code paths and need different arguments.
After this change, you call
cpudl_clear(cp, cpu)
cpudl_set(cp, cpu, dl)
instead of
cpudl_set(cp, cpu, 0 /* dl */, 0 /* is_valid */)
cpudl_set(cp, cpu, dl, 1 /* is_valid */)
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
---
kernel/sched/cpudeadline.c | 49 +++++++++++++++++++++++++++++++---------------
kernel/sched/cpudeadline.h | 3 ++-
kernel/sched/deadline.c | 10 +++++-----
3 files changed, 40 insertions(+), 22 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0ace75a..e731190 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -145,16 +145,15 @@ out:
}
/*
- * cpudl_set - update the cpudl max-heap
+ * cpudl_clear - remove a cpu from the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target cpu
- * @dl: the new earliest deadline for this cpu
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
* Returns: (void)
*/
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
+void cpudl_clear(struct cpudl *cp, int cpu)
{
int old_idx, new_cpu;
unsigned long flags;
@@ -162,17 +161,15 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
+
old_idx = cp->elements[cpu].idx;
- if (!is_valid) {
- /* remove item */
- if (old_idx == IDX_INVALID) {
- /*
- * Nothing to remove if old_idx was invalid.
- * This could happen if a rq_offline_dl is
- * called for a CPU without -dl tasks running.
- */
- goto out;
- }
+ if (old_idx == IDX_INVALID) {
+ /*
+ * Nothing to remove if old_idx was invalid.
+ * This could happen if a rq_offline_dl is
+ * called for a CPU without -dl tasks running.
+ */
+ } else {
new_cpu = cp->elements[cp->size - 1].cpu;
cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
cp->elements[old_idx].cpu = new_cpu;
@@ -180,11 +177,32 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cp->elements[new_cpu].idx = old_idx;
cp->elements[cpu].idx = IDX_INVALID;
cpudl_heapify(cp, old_idx);
- cpumask_set_cpu(cpu, cp->free_cpus);
- goto out;
+ cpumask_set_cpu(cpu, cp->free_cpus);
}
+ raw_spin_unlock_irqrestore(&cp->lock, flags);
+}
+
+/*
+ * cpudl_set - update the cpudl max-heap
+ * @cp: the cpudl max-heap context
+ * @cpu: the target cpu
+ * @dl: the new earliest deadline for this cpu
+ *
+ * Notes: assumes cpu_rq(cpu)->lock is locked
+ *
+ * Returns: (void)
+ */
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
+{
+ int old_idx;
+ unsigned long flags;
+
+ WARN_ON(!cpu_present(cpu));
+ raw_spin_lock_irqsave(&cp->lock, flags);
+
+ old_idx = cp->elements[cpu].idx;
if (old_idx == IDX_INVALID) {
int new_idx = cp->size++;
cp->elements[new_idx].dl = dl;
@@ -197,7 +215,6 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cpudl_heapify(cp, old_idx);
}
-out:
raw_spin_unlock_irqrestore(&cp->lock, flags);
}
diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h
index fcbdf83..f7da8c5 100644
--- a/kernel/sched/cpudeadline.h
+++ b/kernel/sched/cpudeadline.h
@@ -23,7 +23,8 @@ struct cpudl {
#ifdef CONFIG_SMP
int cpudl_find(struct cpudl *cp, struct task_struct *p,
struct cpumask *later_mask);
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid);
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl);
+void cpudl_clear(struct cpudl *cp, int cpu);
int cpudl_init(struct cpudl *cp);
void cpudl_set_freecpu(struct cpudl *cp, int cpu);
void cpudl_clear_freecpu(struct cpudl *cp, int cpu);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d091f4a..18fb0b8 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -798,7 +798,7 @@ static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
if (dl_rq->earliest_dl.curr == 0 ||
dl_time_before(deadline, dl_rq->earliest_dl.curr)) {
dl_rq->earliest_dl.curr = deadline;
- cpudl_set(&rq->rd->cpudl, rq->cpu, deadline, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, deadline);
}
}
@@ -813,14 +813,14 @@ static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
if (!dl_rq->dl_nr_running) {
dl_rq->earliest_dl.curr = 0;
dl_rq->earliest_dl.next = 0;
- cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+ cpudl_clear(&rq->rd->cpudl, rq->cpu);
} else {
struct rb_node *leftmost = dl_rq->rb_leftmost;
struct sched_dl_entity *entry;
entry = rb_entry(leftmost, struct sched_dl_entity, rb_node);
dl_rq->earliest_dl.curr = entry->deadline;
- cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline);
}
}
@@ -1671,7 +1671,7 @@ static void rq_online_dl(struct rq *rq)
cpudl_set_freecpu(&rq->rd->cpudl, rq->cpu);
if (rq->dl.dl_nr_running > 0)
- cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr);
}
/* Assumes rq->lock is held */
@@ -1680,7 +1680,7 @@ static void rq_offline_dl(struct rq *rq)
if (rq->dl.overloaded)
dl_clear_overload(rq);
- cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+ cpudl_clear(&rq->rd->cpudl, rq->cpu);
cpudl_clear_freecpu(&rq->rd->cpudl, rq->cpu);
}
--
2.7.4
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:sched/core] sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear()
2016-08-14 14:27 ` [RFC PATCH 3/3] sched/deadline: split cpudl_set() into cpudl_set() and cpudl_clear() Tommaso Cucinotta
@ 2016-09-05 11:54 ` tip-bot for Tommaso Cucinotta
0 siblings, 0 replies; 8+ messages in thread
From: tip-bot for Tommaso Cucinotta @ 2016-09-05 11:54 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, torvalds, tommaso.cucinotta, hpa, luca.abeni,
mingo, juri.lelli, peterz, juri.lelli, tglx
Commit-ID: d8206bb3ffe0eaee03abfad46fd44d8b17142e88
Gitweb: http://git.kernel.org/tip/d8206bb3ffe0eaee03abfad46fd44d8b17142e88
Author: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
AuthorDate: Sun, 14 Aug 2016 16:27:08 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 5 Sep 2016 13:29:43 +0200
sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear()
These 2 exercise independent code paths and need different arguments.
After this change, you call:
cpudl_clear(cp, cpu);
cpudl_set(cp, cpu, dl);
instead of:
cpudl_set(cp, cpu, 0 /* dl */, 0 /* is_valid */);
cpudl_set(cp, cpu, dl, 1 /* is_valid */);
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Luca Abeni <luca.abeni@unitn.it>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-dl@retis.sssup.it
Link: http://lkml.kernel.org/r/1471184828-12644-4-git-send-email-tommaso.cucinotta@sssup.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/cpudeadline.c | 49 +++++++++++++++++++++++++++++++---------------
kernel/sched/cpudeadline.h | 3 ++-
kernel/sched/deadline.c | 10 +++++-----
3 files changed, 40 insertions(+), 22 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0ace75a..e731190 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -145,16 +145,15 @@ out:
}
/*
- * cpudl_set - update the cpudl max-heap
+ * cpudl_clear - remove a cpu from the cpudl max-heap
* @cp: the cpudl max-heap context
* @cpu: the target cpu
- * @dl: the new earliest deadline for this cpu
*
* Notes: assumes cpu_rq(cpu)->lock is locked
*
* Returns: (void)
*/
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
+void cpudl_clear(struct cpudl *cp, int cpu)
{
int old_idx, new_cpu;
unsigned long flags;
@@ -162,17 +161,15 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
+
old_idx = cp->elements[cpu].idx;
- if (!is_valid) {
- /* remove item */
- if (old_idx == IDX_INVALID) {
- /*
- * Nothing to remove if old_idx was invalid.
- * This could happen if a rq_offline_dl is
- * called for a CPU without -dl tasks running.
- */
- goto out;
- }
+ if (old_idx == IDX_INVALID) {
+ /*
+ * Nothing to remove if old_idx was invalid.
+ * This could happen if a rq_offline_dl is
+ * called for a CPU without -dl tasks running.
+ */
+ } else {
new_cpu = cp->elements[cp->size - 1].cpu;
cp->elements[old_idx].dl = cp->elements[cp->size - 1].dl;
cp->elements[old_idx].cpu = new_cpu;
@@ -180,11 +177,32 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cp->elements[new_cpu].idx = old_idx;
cp->elements[cpu].idx = IDX_INVALID;
cpudl_heapify(cp, old_idx);
- cpumask_set_cpu(cpu, cp->free_cpus);
- goto out;
+ cpumask_set_cpu(cpu, cp->free_cpus);
}
+ raw_spin_unlock_irqrestore(&cp->lock, flags);
+}
+
+/*
+ * cpudl_set - update the cpudl max-heap
+ * @cp: the cpudl max-heap context
+ * @cpu: the target cpu
+ * @dl: the new earliest deadline for this cpu
+ *
+ * Notes: assumes cpu_rq(cpu)->lock is locked
+ *
+ * Returns: (void)
+ */
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
+{
+ int old_idx;
+ unsigned long flags;
+
+ WARN_ON(!cpu_present(cpu));
+ raw_spin_lock_irqsave(&cp->lock, flags);
+
+ old_idx = cp->elements[cpu].idx;
if (old_idx == IDX_INVALID) {
int new_idx = cp->size++;
cp->elements[new_idx].dl = dl;
@@ -197,7 +215,6 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
cpudl_heapify(cp, old_idx);
}
-out:
raw_spin_unlock_irqrestore(&cp->lock, flags);
}
diff --git a/kernel/sched/cpudeadline.h b/kernel/sched/cpudeadline.h
index fcbdf83..f7da8c5 100644
--- a/kernel/sched/cpudeadline.h
+++ b/kernel/sched/cpudeadline.h
@@ -23,7 +23,8 @@ struct cpudl {
#ifdef CONFIG_SMP
int cpudl_find(struct cpudl *cp, struct task_struct *p,
struct cpumask *later_mask);
-void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid);
+void cpudl_set(struct cpudl *cp, int cpu, u64 dl);
+void cpudl_clear(struct cpudl *cp, int cpu);
int cpudl_init(struct cpudl *cp);
void cpudl_set_freecpu(struct cpudl *cp, int cpu);
void cpudl_clear_freecpu(struct cpudl *cp, int cpu);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d091f4a..18fb0b8 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -798,7 +798,7 @@ static void inc_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
if (dl_rq->earliest_dl.curr == 0 ||
dl_time_before(deadline, dl_rq->earliest_dl.curr)) {
dl_rq->earliest_dl.curr = deadline;
- cpudl_set(&rq->rd->cpudl, rq->cpu, deadline, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, deadline);
}
}
@@ -813,14 +813,14 @@ static void dec_dl_deadline(struct dl_rq *dl_rq, u64 deadline)
if (!dl_rq->dl_nr_running) {
dl_rq->earliest_dl.curr = 0;
dl_rq->earliest_dl.next = 0;
- cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+ cpudl_clear(&rq->rd->cpudl, rq->cpu);
} else {
struct rb_node *leftmost = dl_rq->rb_leftmost;
struct sched_dl_entity *entry;
entry = rb_entry(leftmost, struct sched_dl_entity, rb_node);
dl_rq->earliest_dl.curr = entry->deadline;
- cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, entry->deadline);
}
}
@@ -1671,7 +1671,7 @@ static void rq_online_dl(struct rq *rq)
cpudl_set_freecpu(&rq->rd->cpudl, rq->cpu);
if (rq->dl.dl_nr_running > 0)
- cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr, 1);
+ cpudl_set(&rq->rd->cpudl, rq->cpu, rq->dl.earliest_dl.curr);
}
/* Assumes rq->lock is held */
@@ -1680,7 +1680,7 @@ static void rq_offline_dl(struct rq *rq)
if (rq->dl.overloaded)
dl_clear_overload(rq);
- cpudl_set(&rq->rd->cpudl, rq->cpu, 0, 0);
+ cpudl_clear(&rq->rd->cpudl, rq->cpu);
cpudl_clear_freecpu(&rq->rd->cpudl, rq->cpu);
}
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: SCHED_DEADLINE cpudeadline.{h,c} fixup
2016-08-14 14:27 ` SCHED_DEADLINE cpudeadline.{h,c} fixup Tommaso Cucinotta
` (2 preceding siblings ...)
2016-08-14 14:27 ` [RFC PATCH 3/3] sched/deadline: split cpudl_set() into cpudl_set() and cpudl_clear() Tommaso Cucinotta
@ 2016-08-19 12:58 ` Peter Zijlstra
3 siblings, 0 replies; 8+ messages in thread
From: Peter Zijlstra @ 2016-08-19 12:58 UTC (permalink / raw)
To: Tommaso Cucinotta
Cc: Luca Abeni, Juri Lelli, Ingo Molnar, linux-kernel, linux-dl
On Sun, Aug 14, 2016 at 04:27:05PM +0200, Tommaso Cucinotta wrote:
> Hi,
>
> this is a rework of the cpudeadline bugfix and speed-up patch-set, that
> integrates all comments received so far from Luca, Juri and Peter.
>
> Compared with the previous post, here:
> -) I'm keeping out the minimally invasive bugfix, as it's already been
> merged in tip/sched/core
> -) I moved some little code refactory around change_key_dl() out of the
> (now) 2nd patch, to the 1st one. Now the 2nd (speed-up) patch just
> changes the heapify_up/down() functions
> -) I rebased on top of commit f0b22e39
> -) I repeated an extensive set of tests through the framework published
> separately at: https://github.com/tomcucinotta/cpudl-bench
> repeating new no-behavior-change tests, new heap-consistency tests,
> and new a/b benchmarks (I'm working on a new i5 laptop now), results at:
> https://github.com/tomcucinotta/cpudl-bench/blob/master/cpudl-100000.pdf
> highlighting up to a 14% speed-up when averaging over 100K ops. See the
> enclosed README in that repo for more info.
Thanks!
^ permalink raw reply [flat|nested] 8+ messages in thread