Eric Lee / smarc-ti-linux-kernel

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Commit 184748cc50b2dceb8287f9fb657eda48ff8fcfe7

Authored by Peter Zijlstra
Committed by Ingo Molnar
1 parent a4c98f8bbe
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() 

For future rework of try_to_wake_up() we'd like to push part of that
function onto the CPU the task is actually going to run on.

In order to do so we need a generic callback from the existing scheduler IPI.

This patch introduces such a generic callback: scheduler_ipi() and
implements it as a NOP.

BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions!

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl

Showing 26 changed files with 63 additions and 50 deletions Side-by-side Diff

arch/alpha/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -585,8 +585,7 @@
585 585  
586 586 switch (which) {
587 587 case IPI_RESCHEDULE:
588   - /* Reschedule callback. Everything to be done
589   - is done by the interrupt return path. */
  588 + scheduler_ipi();
590 589 break;
591 590  
592 591 case IPI_CALL_FUNC:
arch/arm/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -560,10 +560,7 @@
560 560 break;
561 561  
562 562 case IPI_RESCHEDULE:
563   - /*
564   - * nothing more to do - eveything is
565   - * done on the interrupt return path
566   - */
  563 + scheduler_ipi();
567 564 break;
568 565  
569 566 case IPI_CALL_FUNC:
arch/blackfin/mach-common/smp.c
Diff comments   View file @ 184748c
... ... @@ -164,6 +164,9 @@
164 164 while (msg_queue->count) {
165 165 msg = &msg_queue->ipi_message[msg_queue->head];
166 166 switch (msg->type) {
  167 + case BFIN_IPI_RESCHEDULE:
  168 + scheduler_ipi();
  169 + break;
167 170 case BFIN_IPI_CALL_FUNC:
168 171 spin_unlock_irqrestore(&msg_queue->lock, flags);
169 172 ipi_call_function(cpu, msg);
arch/cris/arch-v32/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -342,15 +342,18 @@
342 342  
343 343 ipi = REG_RD(intr_vect, irq_regs[smp_processor_id()], rw_ipi);
344 344  
  345 + if (ipi.vector & IPI_SCHEDULE) {
  346 + scheduler_ipi();
  347 + }
345 348 if (ipi.vector & IPI_CALL) {
346   - func(info);
  349 + func(info);
347 350 }
348 351 if (ipi.vector & IPI_FLUSH_TLB) {
349   - if (flush_mm == FLUSH_ALL)
350   - __flush_tlb_all();
351   - else if (flush_vma == FLUSH_ALL)
  352 + if (flush_mm == FLUSH_ALL)
  353 + __flush_tlb_all();
  354 + else if (flush_vma == FLUSH_ALL)
352 355 __flush_tlb_mm(flush_mm);
353   - else
  356 + else
354 357 __flush_tlb_page(flush_vma, flush_addr);
355 358 }
356 359  
arch/ia64/kernel/irq_ia64.c
Diff comments   View file @ 184748c
... ... @@ -31,6 +31,7 @@
31 31 #include <linux/irq.h>
32 32 #include <linux/ratelimit.h>
33 33 #include <linux/acpi.h>
  34 +#include <linux/sched.h>
34 35  
35 36 #include <asm/delay.h>
36 37 #include <asm/intrinsics.h>
... ... @@ -496,6 +497,7 @@
496 497 smp_local_flush_tlb();
497 498 kstat_incr_irqs_this_cpu(irq, desc);
498 499 } else if (unlikely(IS_RESCHEDULE(vector))) {
  500 + scheduler_ipi();
499 501 kstat_incr_irqs_this_cpu(irq, desc);
500 502 } else {
501 503 ia64_setreg(_IA64_REG_CR_TPR, vector);
arch/ia64/xen/irq_xen.c
Diff comments   View file @ 184748c
... ... @@ -92,6 +92,8 @@
92 92 static int xen_slab_ready;
93 93  
94 94 #ifdef CONFIG_SMP
  95 +#include <linux/sched.h>
  96 +
95 97 /* Dummy stub. Though we may check XEN_RESCHEDULE_VECTOR before __do_IRQ,
96 98 * it ends up to issue several memory accesses upon percpu data and
97 99 * thus adds unnecessary traffic to other paths.
98 100  
... ... @@ -99,7 +101,13 @@
99 101 static irqreturn_t
100 102 xen_dummy_handler(int irq, void *dev_id)
101 103 {
  104 + return IRQ_HANDLED;
  105 +}
102 106  
  107 +static irqreturn_t
  108 +xen_resched_handler(int irq, void *dev_id)
  109 +{
  110 + scheduler_ipi();
103 111 return IRQ_HANDLED;
104 112 }
105 113  
... ... @@ -110,7 +118,7 @@
110 118 };
111 119  
112 120 static struct irqaction xen_resched_irqaction = {
113   - .handler = xen_dummy_handler,
  121 + .handler = xen_resched_handler,
114 122 .flags = IRQF_DISABLED,
115 123 .name = "resched"
116 124 };
arch/m32r/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -122,8 +122,6 @@
122 122 *
123 123 * Description: This routine executes on CPU which received
124 124 * 'RESCHEDULE_IPI'.
125   - * Rescheduling is processed at the exit of interrupt
126   - * operation.
127 125 *
128 126 * Born on Date: 2002.02.05
129 127 *
... ... @@ -138,7 +136,7 @@
138 136 *==========================================================================*/
139 137 void smp_reschedule_interrupt(void)
140 138 {
141   - /* nothing to do */
  139 + scheduler_ipi();
142 140 }
143 141  
144 142 /*==========================================================================*
arch/mips/cavium-octeon/smp.c
Diff comments   View file @ 184748c
... ... @@ -44,6 +44,8 @@
44 44  
45 45 if (action & SMP_CALL_FUNCTION)
46 46 smp_call_function_interrupt();
  47 + if (action & SMP_RESCHEDULE_YOURSELF)
  48 + scheduler_ipi();
47 49  
48 50 /* Check if we've been told to flush the icache */
49 51 if (action & SMP_ICACHE_FLUSH)
arch/mips/kernel/smtc.c
Diff comments   View file @ 184748c
... ... @@ -929,7 +929,7 @@
929 929  
930 930 static void ipi_resched_interrupt(void)
931 931 {
932   - /* Return from interrupt should be enough to cause scheduler check */
  932 + scheduler_ipi();
933 933 }
934 934  
935 935 static void ipi_call_interrupt(void)
arch/mips/mti-malta/malta-int.c
Diff comments   View file @ 184748c
... ... @@ -309,6 +309,8 @@
309 309  
310 310 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
311 311 {
  312 + scheduler_ipi();
  313 +
312 314 return IRQ_HANDLED;
313 315 }
314 316  
arch/mips/pmc-sierra/yosemite/smp.c
Diff comments   View file @ 184748c
... ... @@ -55,6 +55,8 @@
55 55  
56 56 if (status & 0x2)
57 57 smp_call_function_interrupt();
  58 + if (status & 0x4)
  59 + scheduler_ipi();
58 60 break;
59 61  
60 62 case 1:
... ... @@ -63,6 +65,8 @@
63 65  
64 66 if (status & 0x2)
65 67 smp_call_function_interrupt();
  68 + if (status & 0x4)
  69 + scheduler_ipi();
66 70 break;
67 71 }
68 72 }
arch/mips/sgi-ip27/ip27-irq.c
Diff comments   View file @ 184748c
... ... @@ -147,8 +147,10 @@
147 147 #ifdef CONFIG_SMP
148 148 if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
149 149 LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
  150 + scheduler_ipi();
150 151 } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
151 152 LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
  153 + scheduler_ipi();
152 154 } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
153 155 LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
154 156 smp_call_function_interrupt();
arch/mips/sibyte/bcm1480/smp.c
Diff comments   View file @ 184748c
... ... @@ -20,6 +20,7 @@
20 20 #include <linux/delay.h>
21 21 #include <linux/smp.h>
22 22 #include <linux/kernel_stat.h>
  23 +#include <linux/sched.h>
23 24  
24 25 #include <asm/mmu_context.h>
25 26 #include <asm/io.h>
... ... @@ -189,10 +190,8 @@
189 190 /* Clear the mailbox to clear the interrupt */
190 191 __raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
191 192  
192   - /*
193   - * Nothing to do for SMP_RESCHEDULE_YOURSELF; returning from the
194   - * interrupt will do the reschedule for us
195   - */
  193 + if (action & SMP_RESCHEDULE_YOURSELF)
  194 + scheduler_ipi();
196 195  
197 196 if (action & SMP_CALL_FUNCTION)
198 197 smp_call_function_interrupt();
arch/mips/sibyte/sb1250/smp.c
Diff comments   View file @ 184748c
... ... @@ -21,6 +21,7 @@
21 21 #include <linux/interrupt.h>
22 22 #include <linux/smp.h>
23 23 #include <linux/kernel_stat.h>
  24 +#include <linux/sched.h>
24 25  
25 26 #include <asm/mmu_context.h>
26 27 #include <asm/io.h>
... ... @@ -177,10 +178,8 @@
177 178 /* Clear the mailbox to clear the interrupt */
178 179 ____raw_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
179 180  
180   - /*
181   - * Nothing to do for SMP_RESCHEDULE_YOURSELF; returning from the
182   - * interrupt will do the reschedule for us
183   - */
  181 + if (action & SMP_RESCHEDULE_YOURSELF)
  182 + scheduler_ipi();
184 183  
185 184 if (action & SMP_CALL_FUNCTION)
186 185 smp_call_function_interrupt();
arch/mn10300/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -494,14 +494,11 @@
494 494 * @irq: The interrupt number.
495 495 * @dev_id: The device ID.
496 496 *
497   - * We need do nothing here, since the scheduling will be effected on our way
498   - * back through entry.S.
499   - *
500 497 * Returns IRQ_HANDLED to indicate we handled the interrupt successfully.
501 498 */
502 499 static irqreturn_t smp_reschedule_interrupt(int irq, void *dev_id)
503 500 {
504   - /* do nothing */
  501 + scheduler_ipi();
505 502 return IRQ_HANDLED;
506 503 }
507 504  
arch/parisc/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -155,10 +155,7 @@
155 155  
156 156 case IPI_RESCHEDULE:
157 157 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
158   - /*
159   - * Reschedule callback. Everything to be
160   - * done is done by the interrupt return path.
161   - */
  158 + scheduler_ipi();
162 159 break;
163 160  
164 161 case IPI_CALL_FUNC:
arch/powerpc/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -116,7 +116,7 @@
116 116 generic_smp_call_function_interrupt();
117 117 break;
118 118 case PPC_MSG_RESCHEDULE:
119   - /* we notice need_resched on exit */
  119 + scheduler_ipi();
120 120 break;
121 121 case PPC_MSG_CALL_FUNC_SINGLE:
122 122 generic_smp_call_function_single_interrupt();
... ... @@ -146,7 +146,7 @@
146 146  
147 147 static irqreturn_t reschedule_action(int irq, void *data)
148 148 {
149   - /* we just need the return path side effect of checking need_resched */
  149 + scheduler_ipi();
150 150 return IRQ_HANDLED;
151 151 }
152 152  
arch/s390/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -165,11 +165,11 @@
165 165 kstat_cpu(smp_processor_id()).irqs[EXTINT_IPI]++;
166 166 /*
167 167 * handle bit signal external calls
168   - *
169   - * For the ec_schedule signal we have to do nothing. All the work
170   - * is done automatically when we return from the interrupt.
171 168 */
172 169 bits = xchg(&S390_lowcore.ext_call_fast, 0);
  170 +
  171 + if (test_bit(ec_schedule, &bits))
  172 + scheduler_ipi();
173 173  
174 174 if (test_bit(ec_call_function, &bits))
175 175 generic_smp_call_function_interrupt();
arch/sh/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -20,6 +20,7 @@
20 20 #include <linux/module.h>
21 21 #include <linux/cpu.h>
22 22 #include <linux/interrupt.h>
  23 +#include <linux/sched.h>
23 24 #include <asm/atomic.h>
24 25 #include <asm/processor.h>
25 26 #include <asm/system.h>
... ... @@ -323,6 +324,7 @@
323 324 generic_smp_call_function_interrupt();
324 325 break;
325 326 case SMP_MSG_RESCHEDULE:
  327 + scheduler_ipi();
326 328 break;
327 329 case SMP_MSG_FUNCTION_SINGLE:
328 330 generic_smp_call_function_single_interrupt();
arch/sparc/kernel/smp_32.c
Diff comments   View file @ 184748c
... ... @@ -125,7 +125,9 @@
125 125  
126 126 void smp_send_reschedule(int cpu)
127 127 {
128   - /* See sparc64 */
  128 + /*
  129 + * XXX missing reschedule IPI, see scheduler_ipi()
  130 + */
129 131 }
130 132  
131 133 void smp_send_stop(void)
arch/sparc/kernel/smp_64.c
Diff comments   View file @ 184748c
... ... @@ -1368,6 +1368,7 @@
1368 1368 void __irq_entry smp_receive_signal_client(int irq, struct pt_regs *regs)
1369 1369 {
1370 1370 clear_softint(1 << irq);
  1371 + scheduler_ipi();
1371 1372 }
1372 1373  
1373 1374 /* This is a nop because we capture all other cpus
arch/tile/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -189,12 +189,8 @@
189 189 /* Called when smp_send_reschedule() triggers IRQ_RESCHEDULE. */
190 190 static irqreturn_t handle_reschedule_ipi(int irq, void *token)
191 191 {
192   - /*
193   - * Nothing to do here; when we return from interrupt, the
194   - * rescheduling will occur there. But do bump the interrupt
195   - * profiler count in the meantime.
196   - */
197 192 __get_cpu_var(irq_stat).irq_resched_count++;
  193 + scheduler_ipi();
198 194  
199 195 return IRQ_HANDLED;
200 196 }
arch/um/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -173,7 +173,7 @@
173 173 break;
174 174  
175 175 case 'R':
176   - set_tsk_need_resched(current);
  176 + scheduler_ipi();
177 177 break;
178 178  
179 179 case 'S':
arch/x86/kernel/smp.c
Diff comments   View file @ 184748c
... ... @@ -194,14 +194,13 @@
194 194 }
195 195  
196 196 /*
197   - * Reschedule call back. Nothing to do,
198   - * all the work is done automatically when
199   - * we return from the interrupt.
  197 + * Reschedule call back.
200 198 */
201 199 void smp_reschedule_interrupt(struct pt_regs *regs)
202 200 {
203 201 ack_APIC_irq();
204 202 inc_irq_stat(irq_resched_count);
  203 + scheduler_ipi();
205 204 /*
206 205 * KVM uses this interrupt to force a cpu out of guest mode
207 206 */
... ... @@ -46,13 +46,12 @@
46 46 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
47 47  
48 48 /*
49   - * Reschedule call back. Nothing to do,
50   - * all the work is done automatically when
51   - * we return from the interrupt.
  49 + * Reschedule call back.
52 50 */
53 51 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
54 52 {
55 53 inc_irq_stat(irq_resched_count);
  54 + scheduler_ipi();
56 55  
57 56 return IRQ_HANDLED;
58 57 }
include/linux/sched.h
Diff comments   View file @ 184748c
... ... @@ -2189,8 +2189,10 @@
2189 2189 extern char *get_task_comm(char *to, struct task_struct *tsk);
2190 2190  
2191 2191 #ifdef CONFIG_SMP
  2192 +static inline void scheduler_ipi(void) { }
2192 2193 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2193 2194 #else
  2195 +static inline void scheduler_ipi(void) { }
2194 2196 static inline unsigned long wait_task_inactive(struct task_struct *p,
2195 2197 long match_state)
2196 2198 {