(Ingo, I apologize for the duplicate emails. I did not have my email config
set up properly and was thus getting rejected by lkml.)
I have attached a patch to add realtime support for PowerPC (32 bit
only). The patch applies over Ingo's real-time preempt patch:
http://people.redhat.com/mingo/realtime-preempt/realtime-preempt-2.6.11-rc4-V0.7.39-02
This patch has been tested on the IBM PPC 405GP eval board only.
You might notice that this board is not an SMP board. A few small
changes were required to build an SMP kernel, even though only one cpu
is actually active. I can supply a patch of the SMP related changes if
anyone desires it.
The testing has included a short (~ten minute) stress test for eight
configuration permutations. The permutations are:
SMP=nSMP=y
--- ---
PREEMPT_NONE pn pn_smp
PREEMPT_VOLUNTARY pv pv_smp
PREEMPT_DESKTOP pd pd_smp
PREEMPT_RTpr pr_smp
Any comments, suggestions, needed changes, etc are welcome.
Thanks,
-Frank
Frank Rowand <[EMAIL PROTECTED]>
MontaVista Software, Inc
Source: MontaVista Software, Inc.
Signed-off-by: Frank Rowand <[EMAIL PROTECTED]>
Index: linux-2.6.10/arch/ppc/Kconfig
===
--- linux-2.6.10.orig/arch/ppc/Kconfig
+++ linux-2.6.10/arch/ppc/Kconfig
@@ -17,9 +17,16 @@ config GENERIC_HARDIRQS
config RWSEM_GENERIC_SPINLOCK
bool
+ depends on !PREEMPT_RT
+
+config ASM_SEMAPHORES
+ bool
+ depends on !PREEMPT_RT
+ default y
config RWSEM_XCHGADD_ALGORITHM
bool
+ depends on !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT
default y
config GENERIC_CALIBRATE_DELAY
@@ -862,15 +869,7 @@ config NR_CPUS
depends on SMP
default "4"
-config PREEMPT
- bool "Preemptible Kernel"
- help
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
-
- Say Y here if you are building a kernel for a desktop, embedded
- or real-time system. Say N if you are unsure.
+source "lib/Kconfig.RT"
config HIGHMEM
bool "High memory support"
Index: linux-2.6.10/arch/ppc/platforms/prpmc800.c
===
--- linux-2.6.10.orig/arch/ppc/platforms/prpmc800.c
+++ linux-2.6.10/arch/ppc/platforms/prpmc800.c
@@ -331,6 +331,7 @@ static void __init prpmc800_calibrate_de
tb_ticks_per_second = 1 / 4;
tb_ticks_per_jiffy = tb_ticks_per_second / HZ;
tb_to_us = mulhwu_scale_factor(tb_ticks_per_second, 100);
+ us_to_tb = tb_ticks_per_second / 100;
return;
}
@@ -371,6 +372,7 @@ static void __init prpmc800_calibrate_de
tb_ticks_per_second = (tbl_end - tbl_start) * 2;
tb_ticks_per_jiffy = tb_ticks_per_second / HZ;
tb_to_us = mulhwu_scale_factor(tb_ticks_per_second, 100);
+ us_to_tb = tb_ticks_per_second / 100;
}
static void prpmc800_restart(char *cmd)
Index: linux-2.6.10/arch/ppc/syslib/m8xx_setup.c
===
--- linux-2.6.10.orig/arch/ppc/syslib/m8xx_setup.c
+++ linux-2.6.10/arch/ppc/syslib/m8xx_setup.c
@@ -163,6 +163,7 @@ void __init m8xx_calibrate_decr(void)
printk("Decrementer Frequency = %d/%d\n", freq, divisor);
tb_ticks_per_jiffy = freq / HZ / divisor;
tb_to_us = mulhwu_scale_factor(freq / divisor, 100);
+ us_to_tb = (freq / divisor) / 100;
/* Perform some more timer/timebase initialization. This used
* to be done elsewhere, but other changes caused it to get
Index: linux-2.6.10/arch/ppc/platforms/chrp_time.c
===
--- linux-2.6.10.orig/arch/ppc/platforms/chrp_time.c
+++ linux-2.6.10/arch/ppc/platforms/chrp_time.c
@@ -191,4 +191,5 @@ void __init chrp_calibrate_decr(void)
freq/100, freq%100);
tb_ticks_per_jiffy = freq / HZ;
tb_to_us = mulhwu_scale_factor(freq, 100);
+ us_to_tb = freq / 100;
}
Index: linux-2.6.10/arch/ppc/platforms/gemini_setup.c
===
--- linux-2.6.10.orig/arch/ppc/platforms/gemini_setup.c
+++ linux-2.6.10/arch/ppc/platforms/gemini_setup.c
@@ -465,6 +465,7 @@ void __init gemini_calibrate_decr(void)
divisor = 4;
tb_ticks_per_jiffy = freq / HZ / divisor;
tb_to_us = mulhwu_scale_factor(freq/divisor, 100);
+ us_to_tb = (freq / divisor) / 100;
}
unsigned long __init gemini_find_end_of_memory(void)
Index: linux-2.6.10/include/asm-ppc/time.h
===
