I was getting some pretty repeatable oopses while large numbers of
processes were exiting on my 16-way PIII while irqstacks, and 4k stacks
were turned on. It is hard to trigger, and only happens when you're
using 4k stacks, not just irqstacks.
I traced it down to when smp_* interrupts were running. It seems that
they use an interrupt entry path that doesn't include do_IRQ or
common_interrupt. They use a BUILD_INTERRUPT macro, instead. They were
blowing their 4k stacks when running softirqs.
So, what I did, was put the irqstack operations in a macro and call it
from common_interrupt, and the BUILD_INTERRUPT macros. I also had to
change the calling conventions of the newly-affected handlers.
Ben, was there a reason that you didn't include these functions in your
original irqstack patches? I always (wrongly) assumed that they were
really quick interrupts, and didn't use the stack heavily enough to be
worth modifying.
The a diff for the -mjb tree is attached. I'll cook up another set of
vanilla ones tomorrow.
Does anybody want to see irqstacks as a config option? These macros
would make it easier.
-- Dave Hansen haveblue@us.ibm.com
diff -ur linux-2.5.59-mjb1/arch/i386/kernel/apic.c linux-2.5.59-numaq-mjb1/arch/i386/kernel/apic.c --- linux-2.5.59-mjb1/arch/i386/kernel/apic.c Sun Jan 26 23:14:51 2003 +++ linux-2.5.59-numaq-mjb1/arch/i386/kernel/apic.c Sun Jan 26 14:23:22 2003 @@ -1038,7 +1038,8 @@ * interrupt as well. Thus we cannot inline the local irq ... ] */ -void smp_apic_timer_interrupt(struct pt_regs regs) +struct pt_regs * smp_apic_timer_interrupt(struct pt_regs* regs) __attribute__((regparm(1))); +struct pt_regs * smp_apic_timer_interrupt(struct pt_regs* regs) { int cpu = smp_processor_id(); @@ -1058,14 +1059,16 @@ * interrupt lock, which is the WrongThing (tm) to do. */ irq_enter(); - smp_local_timer_interrupt(®s); + smp_local_timer_interrupt(regs); irq_exit(); + return regs; } /* * This interrupt should _never_ happen with our APIC/SMP architecture */ -asmlinkage void smp_spurious_interrupt(void) +struct pt_regs * smp_spurious_interrupt(struct pt_regs* regs) __attribute__((regparm(1))); +struct pt_regs * smp_spurious_interrupt(struct pt_regs* regs) { unsigned long v; @@ -1083,13 +1086,15 @@ printk(KERN_INFO "spurious APIC interrupt on CPU#%d, should never happen.\n", smp_processor_id()); irq_exit(); + return regs; } /* * This interrupt should never happen with our APIC/SMP architecture */ -asmlinkage void smp_error_interrupt(void) +struct pt_regs * smp_error_interrupt(struct pt_regs* regs) __attribute__((regparm(1))); +struct pt_regs * smp_error_interrupt(struct pt_regs* regs) { unsigned long v, v1; @@ -1114,6 +1119,7 @@ printk (KERN_INFO "APIC error on CPU%d: %02lx(%02lx)\n", smp_processor_id(), v , v1); irq_exit(); + return regs; } /* diff -ur linux-2.5.59-mjb1/arch/i386/kernel/entry.S linux-2.5.59-numaq-mjb1/arch/i386/kernel/entry.S --- linux-2.5.59-mjb1/arch/i386/kernel/entry.S Sun Jan 26 23:16:19 2003 +++ linux-2.5.59-numaq-mjb1/arch/i386/kernel/entry.S Sun Jan 26 23:13:23 2003 @@ -138,7 +138,42 @@ .long 1b,2b; \ .previous - +#define SWITCH_TO_IRQSTACK \ + GET_THREAD_INFO(%ebx); \ + movl TI_IRQ_STACK(%ebx),%ecx; \ + movl TI_TASK(%ebx),%edx; \ + movl %esp,%eax; \ + leal (THREAD_SIZE-4)(%ecx),%esi;# %ecx+THREAD_SIZE is next stack\ + # -4 keeps us in the right one \ + testl %ecx,%ecx; # is there a valid irq_stack? \ + \ + # switch to the irq stack \ +#ifdef CONFIG_X86_HAVE_CMOV + cmovnz %esi,%esp; \ +#else \ + jz 1f; \ + mov %esi,%esp; \ +1: \ +#endif + \ + # update the task pointer in the irq stack \ + GET_THREAD_INFO(%esi); \ + movl %edx,TI_TASK(%esi); \ + \ + # update the preempt count in the irq stack \ + movl TI_PRE_COUNT(%ebx),%ecx; \ + movl %ecx,TI_PRE_COUNT(%esi); + +#define RESTORE_FROM_IRQSTACK \ + movl %eax,%esp; # potentially restore non-irq stack \ + \ + # copy flags from the irq stack back into the tasks thread_info \ + # esi is saved over the do_IRQ call and contains the irq stack \ + # thread_info pointer \ + # ebx contains the original thread_info pointer \ + movl TI_FLAGS(%esi),%eax; \ + movl $0,TI_FLAGS(%esi); \ + LOCK orl %eax,TI_FLAGS(%ebx); ENTRY(lcall7) pushfl # We get a different stack layout with call @@ -391,52 +426,16 @@ ALIGN common_interrupt: SAVE_ALL - - - GET_THREAD_INFO(%ebx) - movl TI_IRQ_STACK(%ebx),%ecx - movl TI_TASK(%ebx),%edx - movl %esp,%eax - leal (THREAD_SIZE-4)(%ecx),%esi # %ecx+THREAD_SIZE is next stack - # -4 keeps us in the right one - testl %ecx,%ecx # is there a valid irq_stack? - - # switch to the irq stack -#ifdef CONFIG_X86_HAVE_CMOV - cmovnz %esi,%esp -#else - jz 1f - mov %esi,%esp -1: -#endif - - # update the task pointer in the irq stack - GET_THREAD_INFO(%esi) - movl %edx,TI_TASK(%esi) - - # update the preempt count in the irq stack - movl TI_PRE_COUNT(%ebx),%ecx - movl %ecx,TI_PRE_COUNT(%esi) - + SWITCH_TO_IRQSTACK call do_IRQ - - movl %eax,%esp # potentially restore non-irq stack - - # copy flags from the irq stack back into the task's thread_info - # %esi is saved over the do_IRQ call and contains the irq stack - # thread_info pointer - # %ebx contains the original thread_info pointer - movl TI_FLAGS(%esi),%eax - movl $0,TI_FLAGS(%esi) - LOCK orl %eax,TI_FLAGS(%ebx) - + RESTORE_FROM_IRQSTACK jmp ret_from_intr #define BUILD_INTERRUPT(name, nr) \ ENTRY(name) \ - pushl $nr-256; \ - SAVE_ALL \ - call smp_/**/name; \ + SWITCH_TO_IRQSTACK \ + call smp_/**/name; \ + RESTORE_FROM_IRQSTACK \ jmp ret_from_intr; /* The include is where all of the SMP etc. interrupts come from */ diff -ur linux-2.5.59-mjb1/arch/i386/kernel/smp.c linux-2.5.59-numaq-mjb1/arch/i386/kernel/smp.c --- linux-2.5.59-mjb1/arch/i386/kernel/smp.c Sun Jan 26 23:16:19 2003 +++ linux-2.5.59-numaq-mjb1/arch/i386/kernel/smp.c Sun Jan 26 14:37:09 2003 @@ -305,7 +305,8 @@ * 2) Leave the mm if we are in the lazy tlb mode. */ -asmlinkage void smp_invalidate_interrupt (void) +struct pt_regs *smp_invalidate_interrupt(struct pt_regs *regs) __attribute__((regparm(1))); +struct pt_regs *smp_invalidate_interrupt(struct pt_regs *regs) { unsigned long cpu; @@ -336,6 +337,7 @@ out: put_cpu_no_resched(); + return regs; } static void flush_tlb_others (unsigned long cpumask, struct mm_struct *mm, @@ -598,12 +600,17 @@ * all the work is done automatically when * we return from the interrupt. */ -asmlinkage void smp_reschedule_interrupt(void) + +asmlinkage struct pt_regs * smp_reschedule_interrupt(struct pt_regs *regs) __attribute__((regparm(1))); +struct pt_regs * smp_reschedule_interrupt(struct pt_regs *regs) { ack_APIC_irq(); + return regs; } -asmlinkage void smp_call_function_interrupt(struct pt_regs regs) + +asmlinkage struct pt_regs * smp_call_function_interrupt(struct pt_regs *regs) __attribute__((regparm(1))); +struct pt_regs * smp_call_function_interrupt(struct pt_regs *regs) { void (*func) (void *info, struct pt_regs *) = (void (*)(void *, struct pt_regs*))call_data->func; void *info = call_data->info; @@ -620,12 +627,13 @@ * At this point the info structure may be out of scope unless wait==1 */ irq_enter(); - (*func)(info, ®s); + (*func)(info, regs); irq_exit(); if (wait) { mb(); atomic_inc(&call_data->finished); } + return regs; }
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This archive was generated by hypermail 2b29 : Fri Jan 31 2003 - 22:00:16 EST