diff options
| author | Ashok Raj <ashok.raj@intel.com> | 2005-06-25 14:54:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-25 16:24:29 -0700 |
| commit | 67664c8f7e74def5adf66298a1245d82af72db2c (patch) | |
| tree | c98657d833d3ca61322a8ae54023814ebc36a480 | |
| parent | f370513640492641b4046bfd9a6e4714f6ae530d (diff) | |
| download | linux-67664c8f7e74def5adf66298a1245d82af72db2c.tar.bz2 | |
[PATCH] i386: Dont use IPI broadcast when using cpu hotplug.
This patch introduces a startup parameter no_broadcast. When we enable
CONFIG_HOTPLUG_CPU, we dont want to use broadcast shortcut as it has ill
effects on a offline cpu. If we issue broadcast, the IPI is also delivered
to offline cpus, or partially up cpu causing stale IPI's to be handled,
which is a problem and can cause undesirable effects.
Introduces a new startup cmdline option no_ipi_broadcast, that can be
switched at cmdline if necessary.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/i386/mach-default/setup.c | 27 | ||||
| -rw-r--r-- | include/asm-i386/mach-default/mach_ipi.h | 27 |
2 files changed, 52 insertions, 2 deletions
diff --git a/arch/i386/mach-default/setup.c b/arch/i386/mach-default/setup.c index 0aa08eaa8932..e5a1a83d09ef 100644 --- a/arch/i386/mach-default/setup.c +++ b/arch/i386/mach-default/setup.c @@ -10,6 +10,14 @@ #include <asm/acpi.h> #include <asm/arch_hooks.h> +#ifdef CONFIG_HOTPLUG_CPU +#define DEFAULT_SEND_IPI (1) +#else +#define DEFAULT_SEND_IPI (0) +#endif + +int no_broadcast=DEFAULT_SEND_IPI; + /** * pre_intr_init_hook - initialisation prior to setting up interrupt vectors * @@ -104,3 +112,22 @@ void __init mca_nmi_hook(void) printk("NMI generated from unknown source!\n"); } #endif + +static __init int no_ipi_broadcast(char *str) +{ + get_option(&str, &no_broadcast); + printk ("Using %s mode\n", no_broadcast ? "No IPI Broadcast" : + "IPI Broadcast"); + return 1; +} + +__setup("no_ipi_broadcast", no_ipi_broadcast); + +static int __init print_ipi_mode(void) +{ + printk ("Using IPI %s mode\n", no_broadcast ? "No-Shortcut" : + "Shortcut"); + return 0; +} + +late_initcall(print_ipi_mode); diff --git a/include/asm-i386/mach-default/mach_ipi.h b/include/asm-i386/mach-default/mach_ipi.h index 6f2b17a20089..cc756a67cd63 100644 --- a/include/asm-i386/mach-default/mach_ipi.h +++ b/include/asm-i386/mach-default/mach_ipi.h @@ -4,11 +4,34 @@ void send_IPI_mask_bitmask(cpumask_t mask, int vector); void __send_IPI_shortcut(unsigned int shortcut, int vector); +extern int no_broadcast; + static inline void send_IPI_mask(cpumask_t mask, int vector) { send_IPI_mask_bitmask(mask, vector); } +static inline void __local_send_IPI_allbutself(int vector) +{ + if (no_broadcast) { + cpumask_t mask = cpu_online_map; + int this_cpu = get_cpu(); + + cpu_clear(this_cpu, mask); + send_IPI_mask(mask, vector); + put_cpu(); + } else + __send_IPI_shortcut(APIC_DEST_ALLBUT, vector); +} + +static inline void __local_send_IPI_all(int vector) +{ + if (no_broadcast) + send_IPI_mask(cpu_online_map, vector); + else + __send_IPI_shortcut(APIC_DEST_ALLINC, vector); +} + static inline void send_IPI_allbutself(int vector) { /* @@ -18,13 +41,13 @@ static inline void send_IPI_allbutself(int vector) if (!(num_online_cpus() > 1)) return; - __send_IPI_shortcut(APIC_DEST_ALLBUT, vector); + __local_send_IPI_allbutself(vector); return; } static inline void send_IPI_all(int vector) { - __send_IPI_shortcut(APIC_DEST_ALLINC, vector); + __local_send_IPI_all(vector); } #endif /* __ASM_MACH_IPI_H */ |