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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 16:53:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 16:53:16 -0700
commitce7d0226198aac42ed311dd2783232adc16b296d (patch)
tree64ae863b9fbae4cd16da8a2d8553573bd676e23c
parentb142ebb61cd36370c6fac5e0b8261a6cd7bba782 (diff)
parenta75f5f0f0a3676216e0015b3040c785dbfe1e0da (diff)
Merge branch 'alpha-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6
* 'alpha-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6: alpha: simplify and optimize sched_find_first_bit alpha: invoke oom-killer from page fault Convert alpha to use clocksources instead of arch_gettimeoffset
-rw-r--r--arch/alpha/Kconfig4
-rw-r--r--arch/alpha/include/asm/bitops.h20
-rw-r--r--arch/alpha/kernel/time.c69
-rw-r--r--arch/alpha/mm/fault.c11
4 files changed, 42 insertions, 62 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index b7193986cbf..24efdfe277f 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -51,10 +51,6 @@ config GENERIC_TIME
bool
default y
-config ARCH_USES_GETTIMEOFFSET
- bool
- default y
-
config GENERIC_CMOS_UPDATE
def_bool y
diff --git a/arch/alpha/include/asm/bitops.h b/arch/alpha/include/asm/bitops.h
index 296da1d5ed5..1dce24bc455 100644
--- a/arch/alpha/include/asm/bitops.h
+++ b/arch/alpha/include/asm/bitops.h
@@ -438,22 +438,20 @@ static inline unsigned int __arch_hweight8(unsigned int w)
/*
* Every architecture must define this function. It's the fastest
- * way of searching a 140-bit bitmap where the first 100 bits are
- * unlikely to be set. It's guaranteed that at least one of the 140
- * bits is set.
+ * way of searching a 100-bit bitmap. It's guaranteed that at least
+ * one of the 100 bits is cleared.
*/
static inline unsigned long
-sched_find_first_bit(unsigned long b[3])
+sched_find_first_bit(const unsigned long b[2])
{
- unsigned long b0 = b[0], b1 = b[1], b2 = b[2];
- unsigned long ofs;
+ unsigned long b0, b1, ofs, tmp;
- ofs = (b1 ? 64 : 128);
- b1 = (b1 ? b1 : b2);
- ofs = (b0 ? 0 : ofs);
- b0 = (b0 ? b0 : b1);
+ b0 = b[0];
+ b1 = b[1];
+ ofs = (b0 ? 0 : 64);
+ tmp = (b0 ? b0 : b1);
- return __ffs(b0) + ofs;
+ return __ffs(tmp) + ofs;
}
#include <asm-generic/bitops/ext2-non-atomic.h>
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index 5465e932e56..1efbed82c0f 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -51,6 +51,7 @@
#include <linux/mc146818rtc.h>
#include <linux/time.h>
#include <linux/timex.h>
+#include <linux/clocksource.h>
#include "proto.h"
#include "irq_impl.h"
@@ -332,6 +333,34 @@ rpcc_after_update_in_progress(void)
return rpcc();
}
+#ifndef CONFIG_SMP
+/* Until and unless we figure out how to get cpu cycle counters
+ in sync and keep them there, we can't use the rpcc. */
+static cycle_t read_rpcc(struct clocksource *cs)
+{
+ cycle_t ret = (cycle_t)rpcc();
+ return ret;
+}
+
+static struct clocksource clocksource_rpcc = {
+ .name = "rpcc",
+ .rating = 300,
+ .read = read_rpcc,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS
+};
+
+static inline void register_rpcc_clocksource(long cycle_freq)
+{
+ clocksource_calc_mult_shift(&clocksource_rpcc, cycle_freq, 4);
+ clocksource_register(&clocksource_rpcc);
+}
+#else /* !CONFIG_SMP */
+static inline void register_rpcc_clocksource(long cycle_freq)
+{
+}
+#endif /* !CONFIG_SMP */
+
void __init
time_init(void)
{
@@ -385,6 +414,8 @@ time_init(void)
__you_loose();
}
+ register_rpcc_clocksource(cycle_freq);
+
state.last_time = cc1;
state.scaled_ticks_per_cycle
= ((unsigned long) HZ << FIX_SHIFT) / cycle_freq;
@@ -395,44 +426,6 @@ time_init(void)
}
/*
- * Use the cycle counter to estimate an displacement from the last time
- * tick. Unfortunately the Alpha designers made only the low 32-bits of
- * the cycle counter active, so we overflow on 8.2 seconds on a 500MHz
- * part. So we can't do the "find absolute time in terms of cycles" thing
- * that the other ports do.
- */
-u32 arch_gettimeoffset(void)
-{
-#ifdef CONFIG_SMP
- /* Until and unless we figure out how to get cpu cycle counters
- in sync and keep them there, we can't use the rpcc tricks. */
- return 0;
-#else
- unsigned long delta_cycles, delta_usec, partial_tick;
-
- delta_cycles = rpcc() - state.last_time;
- partial_tick = state.partial_tick;
- /*
- * usec = cycles * ticks_per_cycle * 2**48 * 1e6 / (2**48 * ticks)
- * = cycles * (s_t_p_c) * 1e6 / (2**48 * ticks)
- * = cycles * (s_t_p_c) * 15625 / (2**42 * ticks)
- *
- * which, given a 600MHz cycle and a 1024Hz tick, has a
- * dynamic range of about 1.7e17, which is less than the
- * 1.8e19 in an unsigned long, so we are safe from overflow.
- *
- * Round, but with .5 up always, since .5 to even is harder
- * with no clear gain.
- */
-
- delta_usec = (delta_cycles * state.scaled_ticks_per_cycle
- + partial_tick) * 15625;
- delta_usec = ((delta_usec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
- return delta_usec * 1000;
-#endif
-}
-
-/*
* In order to set the CMOS clock precisely, set_rtc_mmss has to be
* called 500 ms after the second nowtime has started, because when
* nowtime is written into the registers of the CMOS clock, it will
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 00a31deaa96..fadd5f882ff 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -142,7 +142,6 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
goto bad_area;
}
- survive:
/* If for any reason at all we couldn't handle the fault,
make sure we exit gracefully rather than endlessly redo
the fault. */
@@ -188,16 +187,10 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
/* We ran out of memory, or some other thing happened to us that
made us unable to handle the page fault gracefully. */
out_of_memory:
- if (is_global_init(current)) {
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
- printk(KERN_ALERT "VM: killing process %s(%d)\n",
- current->comm, task_pid_nr(current));
if (!user_mode(regs))
goto no_context;
- do_group_exit(SIGKILL);
+ pagefault_out_of_memory();
+ return;
do_sigbus:
/* Send a sigbus, regardless of whether we were in kernel