Re: [RFC PATCH] sched_domains: Make SD_NODE_INIT per-arch

From: Matthew Dobson
Date: Fri Oct 01 2004 - 17:30:33 EST

On Thu, 2004-09-30 at 23:15, Martin J. Bligh wrote:
> --Andrew Morton <akpm@xxxxxxxx> wrote (on Thursday, September 30, 2004 12:23:12 -0700):
>
> > Matthew Dobson <colpatch@xxxxxxxxxx> wrote:
> >>
> >> I would like to try to get this in before then, unless this will really
> >> make things difficult for you.
> >
> > It's about three weeks late for 2.6.9. I already have a string of CPU
> > scheduler patches awaiting the 2.6.10 stream and once we're at -rc2 we
> > really should only be looking at bugfixes.
>
> Yup, seems a bit late for that, but early 2.6.10 would be nice if possible?
>
> > Grumble, mutter.. it looks like one of those "if it compiled, it works"
> > things. Problem is, any time anyone touches that particular piece of the
> > kernel, half the architectures stop compiing.
>
> I tested it - worked for me ;-)
>
> This is the first step to getting the arches to actually use the flexibility
> we had, and stop Andi complaining the scheduler is tuned for one arch rather
> than another ;-) These params definitely need to be per arch/subarch, and
> probably some other ones too, but this seems like a good start.
>
> M.

Martin, Andi, Andrew & anyone else still reading this thread,
Here's yet another version of a patch to implement per-arch SD_*_INITs.
This follows the same basic idea of my last patch, but
1) defines an arch-specific SD_NODE_INIT for the 4 NUMA arches (i386,
x86_64, IA64 & PPC64),
2) defines *default* SD_CPU_INIT & SD_SIBLING_INIT for *all* arches,
with the possibility of them being overridden by simply defining an
arch-specific version in include/asm/topology.h.

The motivation behind the third version of this patch is that Martin
feels that there should be no "default" NUMA initializer because NUMA
characteristics are *very* arch/platform specific, and hence a "default"
NUMA initializer can only lead to confusion. I agree with most of that,
but don't quite see as much harm in having a default as he does.
Nevertheless, to keep him quiet, I've run up this version of the patch.
Martin, please run this through your magic test suite and make sure I
didn't break anything trivial.

[mcd@arrakis source]$ diffstat ~/linux/patches/sched_domains/per_arch-SD_INIT.patch
arch/ia64/kernel/domain.c | 1
include/asm-i386/topology.h | 20 +++++++++++
include/asm-ia64/processor.h | 21 -----------
include/asm-ia64/topology.h | 20 +++++++++++
include/asm-ppc64/topology.h | 20 +++++++++++
include/asm-x86_64/topology.h | 22 ++++++++++++
include/linux/sched.h | 74 +-----------------------------------------
include/linux/topology.h | 72 ++++++++++++++++++++++++++++++++++++++++
8 files changed, 156 insertions(+), 94 deletions(-)


-Matt


diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/arch/ia64/kernel/domain.c linux-2.6.9-rc2-mm4+per_arch-SD_INITs/arch/ia64/kernel/domain.c
--- linux-2.6.9-rc2-mm4/arch/ia64/kernel/domain.c 2004-09-27 15:57:19.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/arch/ia64/kernel/domain.c 2004-09-27 17:42:59.000000000 -0700
@@ -11,7 +11,6 @@
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/topology.h>
-#include <asm/processor.h>

#define SD_NODES_PER_DOMAIN 6

diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/asm-i386/topology.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-i386/topology.h
--- linux-2.6.9-rc2-mm4/include/asm-i386/topology.h 2004-09-16 15:02:45.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-i386/topology.h 2004-10-01 15:06:30.000000000 -0700
@@ -72,6 +72,26 @@ static inline cpumask_t pcibus_to_cpumas
/* Cross-node load balancing interval. */
#define NODE_BALANCE_RATE 100

+/* sched_domains SD_NODE_INIT for NUMAQ machines */
+#define SD_NODE_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 8, \
+ .max_interval = 32, \
+ .busy_factor = 32, \
+ .imbalance_pct = 125, \
+ .cache_hot_time = (10*1000), \
+ .cache_nice_tries = 1, \
+ .per_cpu_gain = 100, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_BALANCE, \
+ .last_balance = jiffies, \
+ .balance_interval = 1, \
+ .nr_balance_failed = 0, \
+}
+
#else /* !CONFIG_NUMA */
/*
* Other i386 platforms should define their own version of the
diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/asm-ia64/processor.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ia64/processor.h
--- linux-2.6.9-rc2-mm4/include/asm-ia64/processor.h 2004-09-27 15:57:51.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ia64/processor.h 2004-09-27 17:40:05.000000000 -0700
@@ -337,27 +337,6 @@ struct task_struct;
/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk) do { } while (0)

-#ifdef CONFIG_NUMA
-#define SD_NODE_INIT (struct sched_domain) { \
- .span = CPU_MASK_NONE, \
- .parent = NULL, \
- .groups = NULL, \
- .min_interval = 80, \
- .max_interval = 320, \
- .busy_factor = 320, \
- .imbalance_pct = 125, \
- .cache_hot_time = (10*1000000), \
- .cache_nice_tries = 1, \
- .per_cpu_gain = 100, \
- .flags = SD_LOAD_BALANCE \
- | SD_BALANCE_EXEC \
- | SD_WAKE_BALANCE, \
- .last_balance = jiffies, \
- .balance_interval = 10, \
- .nr_balance_failed = 0, \
-}
-#endif
-
/*
* This is the mechanism for creating a new kernel thread.
*
diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/asm-ia64/topology.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ia64/topology.h
--- linux-2.6.9-rc2-mm4/include/asm-ia64/topology.h 2004-08-13 22:36:11.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ia64/topology.h 2004-09-30 16:06:47.000000000 -0700
@@ -45,6 +45,26 @@

void build_cpu_to_node_map(void);

+/* sched_domains SD_NODE_INIT for IA64 NUMA machines */
+#define SD_NODE_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 80, \
+ .max_interval = 320, \
+ .busy_factor = 320, \
+ .imbalance_pct = 125, \
+ .cache_hot_time = (10*1000000), \
+ .cache_nice_tries = 1, \
+ .per_cpu_gain = 100, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_BALANCE, \
+ .last_balance = jiffies, \
+ .balance_interval = 10, \
+ .nr_balance_failed = 0, \
+}
+
#endif /* CONFIG_NUMA */

#include <asm-generic/topology.h>
diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/asm-ppc64/topology.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ppc64/topology.h
--- linux-2.6.9-rc2-mm4/include/asm-ppc64/topology.h 2004-08-13 22:38:08.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-ppc64/topology.h 2004-10-01 15:07:24.000000000 -0700
@@ -40,6 +40,26 @@ static inline int node_to_first_cpu(int
/* Cross-node load balancing interval. */
#define NODE_BALANCE_RATE 10

+/* sched_domains SD_NODE_INIT for PPC64 machines */
+#define SD_NODE_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 8, \
+ .max_interval = 32, \
+ .busy_factor = 32, \
+ .imbalance_pct = 125, \
+ .cache_hot_time = (10*1000), \
+ .cache_nice_tries = 1, \
+ .per_cpu_gain = 100, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_BALANCE, \
+ .last_balance = jiffies, \
+ .balance_interval = 1, \
+ .nr_balance_failed = 0, \
+}
+
#else /* !CONFIG_NUMA */

#include <asm-generic/topology.h>
diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/asm-x86_64/topology.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-x86_64/topology.h
--- linux-2.6.9-rc2-mm4/include/asm-x86_64/topology.h 2004-09-16 15:02:46.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/asm-x86_64/topology.h 2004-10-01 15:07:35.000000000 -0700
@@ -34,6 +34,28 @@ static inline cpumask_t __pcibus_to_cpum

#define NODE_BALANCE_RATE 30 /* CHECKME */

+#ifdef CONFIG_NUMA
+/* sched_domains SD_NODE_INIT for x86_64 machines */
+#define SD_NODE_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 8, \
+ .max_interval = 32, \
+ .busy_factor = 32, \
+ .imbalance_pct = 125, \
+ .cache_hot_time = (10*1000), \
+ .cache_nice_tries = 1, \
+ .per_cpu_gain = 100, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_BALANCE, \
+ .last_balance = jiffies, \
+ .balance_interval = 1, \
+ .nr_balance_failed = 0, \
+}
+#endif
+
#endif

#include <asm-generic/topology.h>
diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/linux/sched.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/linux/sched.h
--- linux-2.6.9-rc2-mm4/include/linux/sched.h 2004-09-27 15:57:56.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/linux/sched.h 2004-09-30 16:03:06.000000000 -0700
@@ -30,6 +30,7 @@
#include <linux/completion.h>
#include <linux/pid.h>
#include <linux/percpu.h>
+#include <linux/topology.h>

struct exec_domain;

@@ -486,78 +487,7 @@ extern cpumask_t cpu_isolated_map;
extern void init_sched_build_groups(struct sched_group groups[],
cpumask_t span, int (*group_fn)(int cpu));
extern void cpu_attach_domain(struct sched_domain *sd, int cpu);
-#endif
-
-#ifndef ARCH_HAS_SCHED_TUNE
-#ifdef CONFIG_SCHED_SMT
-#define ARCH_HAS_SCHED_WAKE_IDLE
-/* Common values for SMT siblings */
-#define SD_SIBLING_INIT (struct sched_domain) { \
- .span = CPU_MASK_NONE, \
- .parent = NULL, \
- .groups = NULL, \
- .min_interval = 1, \
- .max_interval = 2, \
- .busy_factor = 8, \
- .imbalance_pct = 110, \
- .cache_hot_time = 0, \
- .cache_nice_tries = 0, \
- .per_cpu_gain = 25, \
- .flags = SD_LOAD_BALANCE \
- | SD_BALANCE_NEWIDLE \
- | SD_BALANCE_EXEC \
- | SD_WAKE_AFFINE \
- | SD_WAKE_IDLE \
- | SD_SHARE_CPUPOWER, \
- .last_balance = jiffies, \
- .balance_interval = 1, \
- .nr_balance_failed = 0, \
-}
-#endif
-
-/* Common values for CPUs */
-#define SD_CPU_INIT (struct sched_domain) { \
- .span = CPU_MASK_NONE, \
- .parent = NULL, \
- .groups = NULL, \
- .min_interval = 1, \
- .max_interval = 4, \
- .busy_factor = 64, \
- .imbalance_pct = 125, \
- .cache_hot_time = (5*1000/2), \
- .cache_nice_tries = 1, \
- .per_cpu_gain = 100, \
- .flags = SD_LOAD_BALANCE \
- | SD_BALANCE_NEWIDLE \
- | SD_BALANCE_EXEC \
- | SD_WAKE_AFFINE \
- | SD_WAKE_BALANCE, \
- .last_balance = jiffies, \
- .balance_interval = 1, \
- .nr_balance_failed = 0, \
-}
-
-#if defined(CONFIG_NUMA) && !defined(SD_NODE_INIT)
-#define SD_NODE_INIT (struct sched_domain) { \
- .span = CPU_MASK_NONE, \
- .parent = NULL, \
- .groups = NULL, \
- .min_interval = 8, \
- .max_interval = 32, \
- .busy_factor = 32, \
- .imbalance_pct = 125, \
- .cache_hot_time = (10*1000), \
- .cache_nice_tries = 1, \
- .per_cpu_gain = 100, \
- .flags = SD_LOAD_BALANCE \
- | SD_BALANCE_EXEC \
- | SD_WAKE_BALANCE, \
- .last_balance = jiffies, \
- .balance_interval = 1, \
- .nr_balance_failed = 0, \
-}
-#endif
-#endif /* ARCH_HAS_SCHED_TUNE */
+#endif /* ARCH_HAS_SCHED_DOMAIN */
#endif /* CONFIG_SMP */


diff -Nurp --exclude-from=/home/mcd/.dontdiff linux-2.6.9-rc2-mm4/include/linux/topology.h linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/linux/topology.h
--- linux-2.6.9-rc2-mm4/include/linux/topology.h 2004-09-16 15:02:47.000000000 -0700
+++ linux-2.6.9-rc2-mm4+per_arch-SD_INITs/include/linux/topology.h 2004-10-01 15:15:56.000000000 -0700
@@ -61,4 +61,76 @@ static inline int __next_node_with_cpus(
#define PENALTY_FOR_NODE_WITH_CPUS (1)
#endif

+/*
+ * Below are the 3 major initializers used in building sched_domains:
+ * SD_SIBLING_INIT, for SMT domains
+ * SD_CPU_INIT, for SMP domains
+ * SD_NODE_INIT, for NUMA domains
+ *
+ * Any architecture that cares to do any tuning to these values should do so
+ * by defining their own arch-specific initializer in include/asm/topology.h.
+ * A definition there will automagically override these default initializers
+ * and allow arch-specific performance tuning of sched_domains.
+ */
+#ifdef CONFIG_SCHED_SMT
+/* MCD - Do we really need this? It is always on if CONFIG_SCHED_SMT is,
+ * so can't we drop this in favor of CONFIG_SCHED_SMT?
+ */
+#define ARCH_HAS_SCHED_WAKE_IDLE
+/* Common values for SMT siblings */
+#ifndef SD_SIBLING_INIT
+#define SD_SIBLING_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 1, \
+ .max_interval = 2, \
+ .busy_factor = 8, \
+ .imbalance_pct = 110, \
+ .cache_hot_time = 0, \
+ .cache_nice_tries = 0, \
+ .per_cpu_gain = 25, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_NEWIDLE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_AFFINE \
+ | SD_WAKE_IDLE \
+ | SD_SHARE_CPUPOWER, \
+ .last_balance = jiffies, \
+ .balance_interval = 1, \
+ .nr_balance_failed = 0, \
+}
+#endif
+#endif /* CONFIG_SCHED_SMT */
+
+/* Common values for CPUs */
+#ifndef SD_CPU_INIT
+#define SD_CPU_INIT (struct sched_domain) { \
+ .span = CPU_MASK_NONE, \
+ .parent = NULL, \
+ .groups = NULL, \
+ .min_interval = 1, \
+ .max_interval = 4, \
+ .busy_factor = 64, \
+ .imbalance_pct = 125, \
+ .cache_hot_time = (5*1000/2), \
+ .cache_nice_tries = 1, \
+ .per_cpu_gain = 100, \
+ .flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_NEWIDLE \
+ | SD_BALANCE_EXEC \
+ | SD_WAKE_AFFINE \
+ | SD_WAKE_BALANCE, \
+ .last_balance = jiffies, \
+ .balance_interval = 1, \
+ .nr_balance_failed = 0, \
+}
+#endif
+
+#ifdef CONFIG_NUMA
+#ifndef SD_NODE_INIT
+#error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
+#endif
+#endif /* CONFIG_NUMA */
+
#endif /* _LINUX_TOPOLOGY_H */


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