From: Mike Travis <travis@sgi.com>
To: Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>, Jes Sorensen <jes@sgi.com>,
David Miller <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] x86: reduce stack requirements for send_call_func_ipi
Date: Fri, 05 Sep 2008 14:40:21 -0700 [thread overview]
Message-ID: <20080905214020.263636000@polaris-admin.engr.sgi.com> (raw)
In-Reply-To: 20080905214019.821172000@polaris-admin.engr.sgi.com
[-- Attachment #1: smp_ops --]
[-- Type: text/plain, Size: 2883 bytes --]
* By converting the internal x86 smp_ops function send_call_func_ipi
to pass a pointer to the cpumask_t variable, we greatly reduce the
stack space required when NR_CPUS=4096.
Further reduction will be realized when the send_IPI_mask interface
is changed in 2.6.28.
Based on 2.6.27-rc5-git6.
Applies to linux-2.6.tip/master (with FUZZ).
Signed-off-by: Mike Travis <travis@sgi.com>
---
arch/x86/kernel/smp.c | 6 +++---
arch/x86/xen/smp.c | 6 +++---
include/asm-x86/smp.h | 6 +++---
3 files changed, 9 insertions(+), 9 deletions(-)
--- linux-2.6.orig/arch/x86/kernel/smp.c
+++ linux-2.6/arch/x86/kernel/smp.c
@@ -126,18 +126,18 @@ void native_send_call_func_single_ipi(in
send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_SINGLE_VECTOR);
}
-void native_send_call_func_ipi(cpumask_t mask)
+void native_send_call_func_ipi(const cpumask_t *mask)
{
cpumask_t allbutself;
allbutself = cpu_online_map;
cpu_clear(smp_processor_id(), allbutself);
- if (cpus_equal(mask, allbutself) &&
+ if (cpus_equal(*mask, allbutself) &&
cpus_equal(cpu_online_map, cpu_callout_map))
send_IPI_allbutself(CALL_FUNCTION_VECTOR);
else
- send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
+ send_IPI_mask(*mask, CALL_FUNCTION_VECTOR);
}
static void stop_this_cpu(void *dummy)
--- linux-2.6.orig/arch/x86/xen/smp.c
+++ linux-2.6/arch/x86/xen/smp.c
@@ -371,14 +371,14 @@ static void xen_send_IPI_mask(cpumask_t
xen_send_IPI_one(cpu, vector);
}
-static void xen_smp_send_call_function_ipi(cpumask_t mask)
+static void xen_smp_send_call_function_ipi(const cpumask_t *mask)
{
int cpu;
- xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
+ xen_send_IPI_mask(*mask, XEN_CALL_FUNCTION_VECTOR);
/* Make sure other vcpus get a chance to run if they need to. */
- for_each_cpu_mask_nr(cpu, mask) {
+ for_each_cpu_mask_nr(cpu, *mask) {
if (xen_vcpu_stolen(cpu)) {
HYPERVISOR_sched_op(SCHEDOP_yield, 0);
break;
--- linux-2.6.orig/include/asm-x86/smp.h
+++ linux-2.6/include/asm-x86/smp.h
@@ -53,7 +53,7 @@ struct smp_ops {
void (*smp_send_stop)(void);
void (*smp_send_reschedule)(int cpu);
- void (*send_call_func_ipi)(cpumask_t mask);
+ void (*send_call_func_ipi)(const cpumask_t *mask);
void (*send_call_func_single_ipi)(int cpu);
};
@@ -103,14 +103,14 @@ static inline void arch_send_call_functi
static inline void arch_send_call_function_ipi(cpumask_t mask)
{
- smp_ops.send_call_func_ipi(mask);
+ smp_ops.send_call_func_ipi(&mask);
}
void native_smp_prepare_boot_cpu(void);
void native_smp_prepare_cpus(unsigned int max_cpus);
void native_smp_cpus_done(unsigned int max_cpus);
int native_cpu_up(unsigned int cpunum);
-void native_send_call_func_ipi(cpumask_t mask);
+void native_send_call_func_ipi(const cpumask_t *mask);
void native_send_call_func_single_ipi(int cpu);
extern int __cpu_disable(void);
next prev parent reply other threads:[~2008-09-05 21:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-05 21:40 [PATCH 0/3] smp: reduce stack requirements for smp_call_function_mask Mike Travis
2008-09-05 21:40 ` [PATCH 1/3] " Mike Travis
2008-09-05 21:40 ` Mike Travis [this message]
2008-09-05 21:40 ` [PATCH 3/3] x86: restore 4096 limit for NR_CPUS Mike Travis
2008-09-06 13:29 ` [PATCH 0/3] smp: reduce stack requirements for smp_call_function_mask Ingo Molnar
2008-09-06 18:12 ` Mike Travis
2008-09-06 18:21 ` Ingo Molnar
2008-09-08 10:30 ` Nick Piggin
2008-09-08 15:47 ` Mike Travis
2008-09-08 19:51 ` David Miller
2008-09-08 20:11 ` Mike Travis
2008-09-08 20:48 ` David Miller
2008-09-08 9:48 ` Jes Sorensen
2008-09-08 15:41 ` Mike Travis
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