diff options
author | Zwane Mwaikambo <zwane@arm.linux.org.uk> | 2006-01-11 16:43:09 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 22:01:57 -0500 |
commit | 329d400f47ddfe8ff599823d739c5c5565da3207 (patch) | |
tree | 903b45e7ebcccbbd8172e207315c036ceb70f6e8 | |
parent | 73ca5358aab55e2e29993a31f3776c54c05ae729 (diff) |
[PATCH] x86_64/i386: Remove preempt disable calls in lowlevel IPI
I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;
...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...
But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.
Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | arch/x86_64/kernel/genapic_cluster.c | 5 | ||||
-rw-r--r-- | arch/x86_64/kernel/genapic_flat.c | 10 | ||||
-rw-r--r-- | include/asm-i386/mach-default/mach_ipi.h | 4 |
3 files changed, 6 insertions, 13 deletions
diff --git a/arch/x86_64/kernel/genapic_cluster.c b/arch/x86_64/kernel/genapic_cluster.c index a472d62f899a..43fcf62fef0f 100644 --- a/arch/x86_64/kernel/genapic_cluster.c +++ b/arch/x86_64/kernel/genapic_cluster.c | |||
@@ -72,14 +72,11 @@ static void cluster_send_IPI_mask(cpumask_t mask, int vector) | |||
72 | static void cluster_send_IPI_allbutself(int vector) | 72 | static void cluster_send_IPI_allbutself(int vector) |
73 | { | 73 | { |
74 | cpumask_t mask = cpu_online_map; | 74 | cpumask_t mask = cpu_online_map; |
75 | int me = get_cpu(); /* Ensure we are not preempted when we clear */ | ||
76 | 75 | ||
77 | cpu_clear(me, mask); | 76 | cpu_clear(smp_processor_id(), mask); |
78 | 77 | ||
79 | if (!cpus_empty(mask)) | 78 | if (!cpus_empty(mask)) |
80 | cluster_send_IPI_mask(mask, vector); | 79 | cluster_send_IPI_mask(mask, vector); |
81 | |||
82 | put_cpu(); | ||
83 | } | 80 | } |
84 | 81 | ||
85 | static void cluster_send_IPI_all(int vector) | 82 | static void cluster_send_IPI_all(int vector) |
diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c index 9da3edb799ea..1a2ab825be98 100644 --- a/arch/x86_64/kernel/genapic_flat.c +++ b/arch/x86_64/kernel/genapic_flat.c | |||
@@ -83,12 +83,11 @@ static void flat_send_IPI_allbutself(int vector) | |||
83 | __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL); | 83 | __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL); |
84 | #else | 84 | #else |
85 | cpumask_t allbutme = cpu_online_map; | 85 | cpumask_t allbutme = cpu_online_map; |
86 | int me = get_cpu(); /* Ensure we are not preempted when we clear */ | 86 | |
87 | cpu_clear(me, allbutme); | 87 | cpu_clear(smp_processor_id(), allbutme); |
88 | 88 | ||
89 | if (!cpus_empty(allbutme)) | 89 | if (!cpus_empty(allbutme)) |
90 | flat_send_IPI_mask(allbutme, vector); | 90 | flat_send_IPI_mask(allbutme, vector); |
91 | put_cpu(); | ||
92 | #endif | 91 | #endif |
93 | } | 92 | } |
94 | 93 | ||
@@ -149,10 +148,9 @@ static void physflat_send_IPI_mask(cpumask_t cpumask, int vector) | |||
149 | static void physflat_send_IPI_allbutself(int vector) | 148 | static void physflat_send_IPI_allbutself(int vector) |
150 | { | 149 | { |
151 | cpumask_t allbutme = cpu_online_map; | 150 | cpumask_t allbutme = cpu_online_map; |
152 | int me = get_cpu(); | 151 | |
153 | cpu_clear(me, allbutme); | 152 | cpu_clear(smp_processor_id(), allbutme); |
154 | physflat_send_IPI_mask(allbutme, vector); | 153 | physflat_send_IPI_mask(allbutme, vector); |
155 | put_cpu(); | ||
156 | } | 154 | } |
157 | 155 | ||
158 | static void physflat_send_IPI_all(int vector) | 156 | static void physflat_send_IPI_all(int vector) |
diff --git a/include/asm-i386/mach-default/mach_ipi.h b/include/asm-i386/mach-default/mach_ipi.h index cc756a67cd63..a1d0072e36bc 100644 --- a/include/asm-i386/mach-default/mach_ipi.h +++ b/include/asm-i386/mach-default/mach_ipi.h | |||
@@ -15,11 +15,9 @@ static inline void __local_send_IPI_allbutself(int vector) | |||
15 | { | 15 | { |
16 | if (no_broadcast) { | 16 | if (no_broadcast) { |
17 | cpumask_t mask = cpu_online_map; | 17 | cpumask_t mask = cpu_online_map; |
18 | int this_cpu = get_cpu(); | ||
19 | 18 | ||
20 | cpu_clear(this_cpu, mask); | 19 | cpu_clear(smp_processor_id(), mask); |
21 | send_IPI_mask(mask, vector); | 20 | send_IPI_mask(mask, vector); |
22 | put_cpu(); | ||
23 | } else | 21 | } else |
24 | __send_IPI_shortcut(APIC_DEST_ALLBUT, vector); | 22 | __send_IPI_shortcut(APIC_DEST_ALLBUT, vector); |
25 | } | 23 | } |