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authorAndi Kleen <ak@suse.de>2005-07-28 21:15:41 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-28 21:46:01 -0700
commit37a47e65fa58d413a31f27ee88f6cb98583b6157 (patch)
tree4c9cc88e9816f174d379d3c0f8066aa78163809f
parent5f68c1388ada34998c2902c289c6a6b625a73c4e (diff)
[PATCH] x86_64: Remove the broadcast options that were added for cpuhotplug
Will be obsolete with physflat. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/x86_64/kernel/genapic_flat.c88
1 files changed, 2 insertions, 86 deletions
diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c
index 28284696508..fdfa15f5d2e 100644
--- a/arch/x86_64/kernel/genapic_flat.c
+++ b/arch/x86_64/kernel/genapic_flat.c
@@ -7,8 +7,6 @@
* Hacked for x86-64 by James Cleverdon from i386 architecture code by
* Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
* James Cleverdon.
- * Ashok Raj <ashok.raj@intel.com>
- * Removed IPI broadcast shortcut to support CPU hotplug
*/
#include <linux/config.h>
#include <linux/threads.h>
@@ -20,47 +18,6 @@
#include <asm/smp.h>
#include <asm/ipi.h>
-/*
- * The following permit choosing broadcast IPI shortcut v.s sending IPI only
- * to online cpus via the send_IPI_mask varient.
- * The mask version is my preferred option, since it eliminates a lot of
- * other extra code that would need to be written to cleanup intrs sent
- * to a CPU while offline.
- *
- * Sending broadcast introduces lots of trouble in CPU hotplug situations.
- * These IPI's are delivered to cpu's irrespective of their offline status
- * and could pickup stale intr data when these CPUS are turned online.
- *
- * Not using broadcast is a cleaner approach IMO, but Andi Kleen disagrees with
- * the idea of not using broadcast IPI's anymore. Hence the run time check
- * is introduced, on his request so we can choose an alternate mechanism.
- *
- * Initial wacky performance tests that collect cycle counts show
- * no increase in using mask v.s broadcast version. In fact they seem
- * identical in terms of cycle counts.
- *
- * if we need to use broadcast, we need to do the following.
- *
- * cli;
- * hold call_lock;
- * clear any pending IPI, just ack and clear all pending intr
- * set cpu_online_map;
- * release call_lock;
- * sti;
- *
- * The complicated dummy irq processing shown above is not required if
- * we didnt sent IPI's to wrong CPU's in the first place.
- *
- * - Ashok Raj <ashok.raj@intel.com>
- */
-#ifdef CONFIG_HOTPLUG_CPU
-#define DEFAULT_SEND_IPI (1)
-#else
-#define DEFAULT_SEND_IPI (0)
-#endif
-
-static int no_broadcast=DEFAULT_SEND_IPI;
-
static cpumask_t flat_target_cpus(void)
{
return cpu_online_map;
@@ -119,37 +76,15 @@ static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
local_irq_restore(flags);
}
-static inline void __local_flat_send_IPI_allbutself(int vector)
-{
- if (no_broadcast) {
- cpumask_t mask = cpu_online_map;
- int this_cpu = get_cpu();
-
- cpu_clear(this_cpu, mask);
- flat_send_IPI_mask(mask, vector);
- put_cpu();
- }
- else
- __send_IPI_shortcut(APIC_DEST_ALLBUT, vector, APIC_DEST_LOGICAL);
-}
-
-static inline void __local_flat_send_IPI_all(int vector)
-{
- if (no_broadcast)
- flat_send_IPI_mask(cpu_online_map, vector);
- else
- __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
-}
-
static void flat_send_IPI_allbutself(int vector)
{
if (((num_online_cpus()) - 1) >= 1)
- __local_flat_send_IPI_allbutself(vector);
+ __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL);
}
static void flat_send_IPI_all(int vector)
{
- __local_flat_send_IPI_all(vector);
+ __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
}
static int flat_apic_id_registered(void)
@@ -170,16 +105,6 @@ static unsigned int phys_pkg_id(int index_msb)
return ((ebx >> 24) & 0xFF) >> index_msb;
}
-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);
-
struct genapic apic_flat = {
.name = "flat",
.int_delivery_mode = dest_LowestPrio,
@@ -194,12 +119,3 @@ struct genapic apic_flat = {
.cpu_mask_to_apicid = flat_cpu_mask_to_apicid,
.phys_pkg_id = phys_pkg_id,
};
-
-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);