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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 19:53:16 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 19:53:16 -0400
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 b7193986cbf9..24efdfe277fc 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -51,10 +51,6 @@ config GENERIC_TIME
51 bool 51 bool
52 default y 52 default y
53 53
54config ARCH_USES_GETTIMEOFFSET
55 bool
56 default y
57
58config GENERIC_CMOS_UPDATE 54config GENERIC_CMOS_UPDATE
59 def_bool y 55 def_bool y
60 56
diff --git a/arch/alpha/include/asm/bitops.h b/arch/alpha/include/asm/bitops.h
index 296da1d5ed57..1dce24bc455a 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)
438 438
439/* 439/*
440 * Every architecture must define this function. It's the fastest 440 * Every architecture must define this function. It's the fastest
441 * way of searching a 140-bit bitmap where the first 100 bits are 441 * way of searching a 100-bit bitmap. It's guaranteed that at least
442 * unlikely to be set. It's guaranteed that at least one of the 140 442 * one of the 100 bits is cleared.
443 * bits is set.
444 */ 443 */
445static inline unsigned long 444static inline unsigned long
446sched_find_first_bit(unsigned long b[3]) 445sched_find_first_bit(const unsigned long b[2])
447{ 446{
448 unsigned long b0 = b[0], b1 = b[1], b2 = b[2]; 447 unsigned long b0, b1, ofs, tmp;
449 unsigned long ofs;
450 448
451 ofs = (b1 ? 64 : 128); 449 b0 = b[0];
452 b1 = (b1 ? b1 : b2); 450 b1 = b[1];
453 ofs = (b0 ? 0 : ofs); 451 ofs = (b0 ? 0 : 64);
454 b0 = (b0 ? b0 : b1); 452 tmp = (b0 ? b0 : b1);
455 453
456 return __ffs(b0) + ofs; 454 return __ffs(tmp) + ofs;
457} 455}
458 456
459#include <asm-generic/bitops/ext2-non-atomic.h> 457#include <asm-generic/bitops/ext2-non-atomic.h>
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index 5465e932e568..1efbed82c0fd 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -51,6 +51,7 @@
51#include <linux/mc146818rtc.h> 51#include <linux/mc146818rtc.h>
52#include <linux/time.h> 52#include <linux/time.h>
53#include <linux/timex.h> 53#include <linux/timex.h>
54#include <linux/clocksource.h>
54 55
55#include "proto.h" 56#include "proto.h"
56#include "irq_impl.h" 57#include "irq_impl.h"
@@ -332,6 +333,34 @@ rpcc_after_update_in_progress(void)
332 return rpcc(); 333 return rpcc();
333} 334}
334 335
336#ifndef CONFIG_SMP
337/* Until and unless we figure out how to get cpu cycle counters
338 in sync and keep them there, we can't use the rpcc. */
339static cycle_t read_rpcc(struct clocksource *cs)
340{
341 cycle_t ret = (cycle_t)rpcc();
342 return ret;
343}
344
345static struct clocksource clocksource_rpcc = {
346 .name = "rpcc",
347 .rating = 300,
348 .read = read_rpcc,
349 .mask = CLOCKSOURCE_MASK(32),
350 .flags = CLOCK_SOURCE_IS_CONTINUOUS
351};
352
353static inline void register_rpcc_clocksource(long cycle_freq)
354{
355 clocksource_calc_mult_shift(&clocksource_rpcc, cycle_freq, 4);
356 clocksource_register(&clocksource_rpcc);
357}
358#else /* !CONFIG_SMP */
359static inline void register_rpcc_clocksource(long cycle_freq)
360{
361}
362#endif /* !CONFIG_SMP */
363
335void __init 364void __init
336time_init(void) 365time_init(void)
337{ 366{
@@ -385,6 +414,8 @@ time_init(void)
385 __you_loose(); 414 __you_loose();
386 } 415 }
387 416
417 register_rpcc_clocksource(cycle_freq);
418
388 state.last_time = cc1; 419 state.last_time = cc1;
389 state.scaled_ticks_per_cycle 420 state.scaled_ticks_per_cycle
390 = ((unsigned long) HZ << FIX_SHIFT) / cycle_freq; 421 = ((unsigned long) HZ << FIX_SHIFT) / cycle_freq;
@@ -395,44 +426,6 @@ time_init(void)
395} 426}
396 427
397/* 428/*
398 * Use the cycle counter to estimate an displacement from the last time
399 * tick. Unfortunately the Alpha designers made only the low 32-bits of
400 * the cycle counter active, so we overflow on 8.2 seconds on a 500MHz
401 * part. So we can't do the "find absolute time in terms of cycles" thing
402 * that the other ports do.
403 */
404u32 arch_gettimeoffset(void)
405{
406#ifdef CONFIG_SMP
407 /* Until and unless we figure out how to get cpu cycle counters
408 in sync and keep them there, we can't use the rpcc tricks. */
409 return 0;
410#else
411 unsigned long delta_cycles, delta_usec, partial_tick;
412
413 delta_cycles = rpcc() - state.last_time;
414 partial_tick = state.partial_tick;
415 /*
416 * usec = cycles * ticks_per_cycle * 2**48 * 1e6 / (2**48 * ticks)
417 * = cycles * (s_t_p_c) * 1e6 / (2**48 * ticks)
418 * = cycles * (s_t_p_c) * 15625 / (2**42 * ticks)
419 *
420 * which, given a 600MHz cycle and a 1024Hz tick, has a
421 * dynamic range of about 1.7e17, which is less than the
422 * 1.8e19 in an unsigned long, so we are safe from overflow.
423 *
424 * Round, but with .5 up always, since .5 to even is harder
425 * with no clear gain.
426 */
427
428 delta_usec = (delta_cycles * state.scaled_ticks_per_cycle
429 + partial_tick) * 15625;
430 delta_usec = ((delta_usec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
431 return delta_usec * 1000;
432#endif
433}
434
435/*
436 * In order to set the CMOS clock precisely, set_rtc_mmss has to be 429 * In order to set the CMOS clock precisely, set_rtc_mmss has to be
437 * called 500 ms after the second nowtime has started, because when 430 * called 500 ms after the second nowtime has started, because when
438 * nowtime is written into the registers of the CMOS clock, it will 431 * 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 00a31deaa96e..fadd5f882ff9 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,
142 goto bad_area; 142 goto bad_area;
143 } 143 }
144 144
145 survive:
146 /* If for any reason at all we couldn't handle the fault, 145 /* If for any reason at all we couldn't handle the fault,
147 make sure we exit gracefully rather than endlessly redo 146 make sure we exit gracefully rather than endlessly redo
148 the fault. */ 147 the fault. */
@@ -188,16 +187,10 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
188 /* We ran out of memory, or some other thing happened to us that 187 /* We ran out of memory, or some other thing happened to us that
189 made us unable to handle the page fault gracefully. */ 188 made us unable to handle the page fault gracefully. */
190 out_of_memory: 189 out_of_memory:
191 if (is_global_init(current)) {
192 yield();
193 down_read(&mm->mmap_sem);
194 goto survive;
195 }
196 printk(KERN_ALERT "VM: killing process %s(%d)\n",
197 current->comm, task_pid_nr(current));
198 if (!user_mode(regs)) 190 if (!user_mode(regs))
199 goto no_context; 191 goto no_context;
200 do_group_exit(SIGKILL); 192 pagefault_out_of_memory();
193 return;
201 194
202 do_sigbus: 195 do_sigbus:
203 /* Send a sigbus, regardless of whether we were in kernel 196 /* Send a sigbus, regardless of whether we were in kernel