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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-25 16:53:16 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-25 16:53:16 -0700 |
commit | ce7d0226198aac42ed311dd2783232adc16b296d (patch) | |
tree | 64ae863b9fbae4cd16da8a2d8553573bd676e23c | |
parent | b142ebb61cd36370c6fac5e0b8261a6cd7bba782 (diff) | |
parent | a75f5f0f0a3676216e0015b3040c785dbfe1e0da (diff) | |
download | kernel_samsung_tuna-ce7d0226198aac42ed311dd2783232adc16b296d.zip kernel_samsung_tuna-ce7d0226198aac42ed311dd2783232adc16b296d.tar.gz kernel_samsung_tuna-ce7d0226198aac42ed311dd2783232adc16b296d.tar.bz2 |
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/Kconfig | 4 | ||||
-rw-r--r-- | arch/alpha/include/asm/bitops.h | 20 | ||||
-rw-r--r-- | arch/alpha/kernel/time.c | 69 | ||||
-rw-r--r-- | arch/alpha/mm/fault.c | 11 |
4 files changed, 42 insertions, 62 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index b719398..24efdfe 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 296da1d..1dce24b 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 5465e93..1efbed8 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 00a31de..fadd5f8 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 |