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Commit ce7d0226 authored by Linus Torvalds's avatar Linus Torvalds
Browse files
* '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
parents b142ebb6 a75f5f0f
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+0 −4
Original line number Diff line number Diff line
@@ -51,10 +51,6 @@ config GENERIC_TIME
	bool
	default y

config ARCH_USES_GETTIMEOFFSET
	bool
	default y

config GENERIC_CMOS_UPDATE
        def_bool y

+9 −11
Original line number Diff line number Diff line
@@ -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>
+31 −38
Original line number Diff line number Diff line
@@ -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;
@@ -394,44 +425,6 @@ time_init(void)
	alpha_mv.init_rtc();
}

/*
 * 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
+2 −9
Original line number Diff line number Diff line
@@ -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