diff -ur linux-2.5.40-clean/arch/i386/config.in linux-2.5.40/arch/i386/config.in
--- linux-2.5.40-clean/arch/i386/config.in 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/config.in 2002-10-02 12:59:55.000000000 -0700
@@ -35,6 +35,7 @@
#
# Define implied options from the CPU selection here
#
+define_bool CONFIG_X86_HAVE_CMOV n
if [ "$CONFIG_M386" = "y" ]; then
define_bool CONFIG_X86_CMPXCHG n
@@ -91,18 +92,21 @@
define_bool CONFIG_X86_GOOD_APIC y
define_bool CONFIG_X86_USE_PPRO_CHECKSUM y
define_bool CONFIG_X86_PPRO_FENCE y
+ define_bool CONFIG_X86_HAVE_CMOV y
fi
if [ "$CONFIG_MPENTIUMIII" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 5
define_bool CONFIG_X86_TSC y
define_bool CONFIG_X86_GOOD_APIC y
define_bool CONFIG_X86_USE_PPRO_CHECKSUM y
+ define_bool CONFIG_X86_HAVE_CMOV y
fi
if [ "$CONFIG_MPENTIUM4" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 7
define_bool CONFIG_X86_TSC y
define_bool CONFIG_X86_GOOD_APIC y
define_bool CONFIG_X86_USE_PPRO_CHECKSUM y
+ define_bool CONFIG_X86_HAVE_CMOV y
fi
if [ "$CONFIG_MK6" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 5
@@ -116,6 +120,7 @@
define_bool CONFIG_X86_GOOD_APIC y
define_bool CONFIG_X86_USE_3DNOW y
define_bool CONFIG_X86_USE_PPRO_CHECKSUM y
+ define_bool CONFIG_X86_HAVE_CMOV y
fi
if [ "$CONFIG_MELAN" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 4
@@ -132,6 +137,7 @@
if [ "$CONFIG_MCRUSOE" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 5
define_bool CONFIG_X86_TSC y
+ define_bool CONFIG_X86_HAVE_CMOV y
fi
if [ "$CONFIG_MWINCHIPC6" = "y" ]; then
define_int CONFIG_X86_L1_CACHE_SHIFT 5
diff -ur linux-2.5.40-clean/arch/i386/kernel/entry.S linux-2.5.40/arch/i386/kernel/entry.S
--- linux-2.5.40-clean/arch/i386/kernel/entry.S 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/entry.S 2002-10-02 13:00:09.000000000 -0700
@@ -136,7 +136,7 @@
movl %ecx,CS(%esp) #
movl %esp, %ebx
pushl %ebx
- andl $-8192, %ebx # GET_THREAD_INFO
+ GET_THREAD_INFO_WITH_ESP(%ebx)
movl TI_EXEC_DOMAIN(%ebx), %edx # Get the execution domain
movl 4(%edx), %edx # Get the lcall7 handler for the domain
pushl $0x7
@@ -158,7 +158,7 @@
movl %ecx,CS(%esp) #
movl %esp, %ebx
pushl %ebx
- andl $-8192, %ebx # GET_THREAD_INFO
+ GET_THREAD_INFO_WITH_ESP(%ebx)
movl TI_EXEC_DOMAIN(%ebx), %edx # Get the execution domain
movl 4(%edx), %edx # Get the lcall7 handler for the domain
pushl $0x27
@@ -334,7 +334,30 @@
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),%ebx
+ testl %ecx,%ecx # is there a valid irq_stack?
+ # switch to the irq stack
+#ifdef CONFIG_X86_HAVE_CMOV
+ cmovnz %ebx,%esp
+#warning using cmov
+#else
+#warning cannot use cmov
+ jnz 1f
+ mov %ebx,%esp
+1:
+#endif
+
+ # update the task pointer in the irq stack
+ GET_THREAD_INFO(%ebx)
+ movl %edx,TI_TASK(%ebx)
+
call do_IRQ
+ movl %eax,%esp # potentially restore non-irq stack
jmp ret_from_intr
#define BUILD_INTERRUPT(name, nr) \
diff -ur linux-2.5.40-clean/arch/i386/kernel/head.S linux-2.5.40/arch/i386/kernel/head.S
--- linux-2.5.40-clean/arch/i386/kernel/head.S 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/head.S 2002-10-02 12:59:55.000000000 -0700
@@ -15,6 +15,7 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/desc.h>
+#include <asm/thread_info.h>
#define OLD_CL_MAGIC_ADDR 0x90020
#define OLD_CL_MAGIC 0xA33F
@@ -305,7 +306,7 @@
ret
ENTRY(stack_start)
- .long init_thread_union+8192
+ .long init_thread_union+THREAD_SIZE
.long __KERNEL_DS
/* This is the default interrupt "handler" :-) */
diff -ur linux-2.5.40-clean/arch/i386/kernel/init_task.c linux-2.5.40/arch/i386/kernel/init_task.c
--- linux-2.5.40-clean/arch/i386/kernel/init_task.c 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/init_task.c 2002-10-02 12:59:55.000000000 -0700
@@ -13,6 +13,9 @@
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
struct mm_struct init_mm = INIT_MM(init_mm);
+union thread_union init_irq_union
+ __attribute__((__section__(".data.init_task")));
+
/*
* Initial thread structure.
*
@@ -22,7 +25,15 @@
*/
union thread_union init_thread_union
__attribute__((__section__(".data.init_task"))) =
- { INIT_THREAD_INFO(init_task) };
+ { {
+ task: &init_task,
+ exec_domain: &default_exec_domain,
+ flags: 0,
+ cpu: 0,
+ addr_limit: KERNEL_DS,
+ irq_stack: &init_irq_union,
+ } };
+
/*
* Initial task structure.
diff -ur linux-2.5.40-clean/arch/i386/kernel/irq.c linux-2.5.40/arch/i386/kernel/irq.c
--- linux-2.5.40-clean/arch/i386/kernel/irq.c 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/irq.c 2002-10-02 12:59:55.000000000 -0700
@@ -311,7 +311,8 @@
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
-asmlinkage unsigned int do_IRQ(struct pt_regs regs)
+struct pt_regs *do_IRQ(struct pt_regs *regs) __attribute__((regparm(1)));
+struct pt_regs *do_IRQ(struct pt_regs *regs)
{
/*
* We ack quickly, we don't want the irq controller
@@ -323,7 +324,7 @@
* 0 return value means that this irq is already being
* handled by some other CPU. (or is disabled)
*/
- int irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code */
+ int irq = regs->orig_eax & 0xff; /* high bits used in ret_from_ code */
int cpu = smp_processor_id();
irq_desc_t *desc = irq_desc + irq;
struct irqaction * action;
@@ -373,7 +374,7 @@
*/
for (;;) {
spin_unlock(&desc->lock);
- handle_IRQ_event(irq, ®s, action);
+ handle_IRQ_event(irq, regs, action);
spin_lock(&desc->lock);
if (likely(!(desc->status & IRQ_PENDING)))
@@ -392,7 +393,7 @@
irq_exit();
- return 1;
+ return regs;
}
/**
diff -ur linux-2.5.40-clean/arch/i386/kernel/process.c linux-2.5.40/arch/i386/kernel/process.c
--- linux-2.5.40-clean/arch/i386/kernel/process.c 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/process.c 2002-10-02 12:59:55.000000000 -0700
@@ -413,6 +413,7 @@
/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
+ next_p->thread_info->irq_stack = prev_p->thread_info->irq_stack;
unlazy_fpu(prev_p);
/*
diff -ur linux-2.5.40-clean/arch/i386/kernel/smpboot.c linux-2.5.40/arch/i386/kernel/smpboot.c
--- linux-2.5.40-clean/arch/i386/kernel/smpboot.c 2002-10-02 12:59:09.000000000 -0700
+++ linux-2.5.40/arch/i386/kernel/smpboot.c 2002-10-02 12:59:55.000000000 -0700
@@ -69,6 +69,10 @@
/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
+extern union thread_union init_irq_union;
+union thread_union *irq_stacks[NR_CPUS] __cacheline_aligned =
+ { &init_irq_union, };
+
/* Set when the idlers are all forked */
int smp_threads_ready;
@@ -763,6 +767,27 @@
return (send_status | accept_status);
}
+static void __init setup_irq_stack(struct task_struct *p, int cpu)
+{
+ unsigned long stk;
+
+ stk = __get_free_pages(GFP_KERNEL, THREAD_ORDER);
+ if (!stk)
+ panic("I can't seem to allocate my irq stack. Oh well, giving up.");
+
+ irq_stacks[cpu] = (void *)stk;
+ memset(irq_stacks[cpu], 0, THREAD_SIZE);
+ irq_stacks[cpu]->thread_info.cpu = cpu;
+ irq_stacks[cpu]->thread_info.preempt_count = 1;
+ /* interrupts are not preemptable */
+ p->thread_info->irq_stack = irq_stacks[cpu];
+
+ /* If we want to make the irq stack more than one unit
+ * deep, we can chain then off of the irq_stack pointer
+ * here.
+ */
+}
+
extern unsigned long cpu_initialized;
static void __init do_boot_cpu (int apicid)
@@ -786,6 +811,8 @@
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
+ setup_irq_stack(idle, cpu);
+
/*
* We remove it from the pidhash and the runqueue
* once we got the process:
@@ -803,7 +830,7 @@
/* So we see what's up */
printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
- stack_start.esp = (void *) (1024 + PAGE_SIZE + (char *)idle->thread_info);
+ stack_start.esp = (void *) (THREAD_SIZE + (char *)idle->thread_info);
/*
* This grunge runs the startup process for
diff -ur linux-2.5.40-clean/include/asm-i386/page.h linux-2.5.40/include/asm-i386/page.h
--- linux-2.5.40-clean/include/asm-i386/page.h 2002-10-02 12:59:03.000000000 -0700
+++ linux-2.5.40/include/asm-i386/page.h 2002-10-02 12:59:55.000000000 -0700
@@ -3,7 +3,11 @@
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
+#ifndef __ASSEMBLY__
#define PAGE_SIZE (1UL << PAGE_SHIFT)
+#else
+#define PAGE_SIZE (1 << PAGE_SHIFT)
+#endif
#define PAGE_MASK (~(PAGE_SIZE-1))
#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
diff -ur linux-2.5.40-clean/include/asm-i386/thread_info.h linux-2.5.40/include/asm-i386/thread_info.h
--- linux-2.5.40-clean/include/asm-i386/thread_info.h 2002-10-02 12:59:03.000000000 -0700
+++ linux-2.5.40/include/asm-i386/thread_info.h 2002-10-02 12:59:55.000000000 -0700
@@ -9,6 +9,7 @@
#ifdef __KERNEL__
+#include <asm/page.h>
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif
@@ -28,9 +29,11 @@
__s32 preempt_count; /* 0 => preemptable, <0 => BUG */
mm_segment_t addr_limit; /* thread address space:
+ 0 for interrupts: illegal
0-0xBFFFFFFF for user-thead
0-0xFFFFFFFF for kernel-thread
*/
+ struct thread_info *irq_stack; /* pointer to cpu irq stack */
__u8 supervisor_stack[0];
};
@@ -44,6 +47,7 @@
#define TI_CPU 0x0000000C
#define TI_PRE_COUNT 0x00000010
#define TI_ADDR_LIMIT 0x00000014
+#define TI_IRQ_STACK 0x00000018
#endif
@@ -54,42 +58,40 @@
*
* preempt_count needs to be 1 initially, until the scheduler is functional.
*/
+#define THREAD_ORDER 0
+
#ifndef __ASSEMBLY__
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .task = &tsk, \
- .exec_domain = &default_exec_domain, \
- .flags = 0, \
- .cpu = 0, \
- .preempt_count = 1, \
- .addr_limit = KERNEL_DS, \
-}
-
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
+/* thread information allocation */
+#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
+#define alloc_thread_info() ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER))
+#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER)
+#define get_thread_info(ti) get_task_struct((ti)->task)
+#define put_thread_info(ti) put_task_struct((ti)->task)
+
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
struct thread_info *ti;
- __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~8191UL));
+ __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
return ti;
}
-/* thread information allocation */
-#define THREAD_SIZE (2*PAGE_SIZE)
-#define alloc_thread_info() ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
-#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
-#define get_thread_info(ti) get_task_struct((ti)->task)
-#define put_thread_info(ti) put_task_struct((ti)->task)
-
#else /* !__ASSEMBLY__ */
+#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
+
/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
- movl $-8192, reg; \
+ movl $-THREAD_SIZE, reg; \
andl %esp, reg
+/* use this one if reg already contains %esp */
+#define GET_THREAD_INFO_WITH_ESP(reg) \
+ andl $-THREAD_SIZE, reg
+
#endif
/*
On Wed, Oct 02, 2002 at 02:18:36PM -0700, Dave Hansen wrote:
> I've resynced Ben's patch against 2.5.40. However, I'm getting some
> strange failures. The patch is good enough to pass LTP, but
> consistently freezes when I run tcpdump on it.
Try running tcpdump with the stack checking patch applied. That should
give you a decent backtrace for the problem.
-ben
On Oct 02, 2002 14:18 -0700, Dave Hansen wrote:
> I've resynced Ben's patch against 2.5.40. However, I'm getting some
> strange failures. The patch is good enough to pass LTP, but
> consistently freezes when I run tcpdump on it.
>
> Although I don't have CONFIG_PREEMPT on, I have the feeling that I
> need to disable preemption in common_interrupt() like it was before.
> Any insights would be appreciated.
I'm a little bit worried about this patch. Have you tried something
like NFS-over-ext3-over-LVM-over-MD or so, which can have a deep stack?
We hit a bunch of deep stack problems like this (overflowing an 8kB stack)
even without interrupts involved when developing Lustre. Granted, we
fixed some large stack allocations in the ext3 indexed-directory code
and in our own code, but I'm still worried that a 4kB stack is too small.
The Stanford checker folks would probably be able to run a test for
large stack allocations in 2.5.40 if you asked them nicely, and maybe
even do stack depths for call chains.
Alternately, you could set up an 8kB stack + IRQ stack and "red-zone"
the high page of the current 8kB stack and see if it is ever used.
Cheers, Andreas
--
Andreas Dilger
http://www-mddsp.enel.ucalgary.ca/People/adilger/
http://sourceforge.net/projects/ext2resize/
Benjamin LaHaise wrote:
> On Wed, Oct 02, 2002 at 02:18:36PM -0700, Dave Hansen wrote:
>
>>I've resynced Ben's patch against 2.5.40. However, I'm getting some
>>strange failures. The patch is good enough to pass LTP, but
>>consistently freezes when I run tcpdump on it.
>
> Try running tcpdump with the stack checking patch applied. That should
> give you a decent backtrace for the problem.
My first suspicion was that it was just overflowing, but not getting
the message out. I just realized that my latest testing (the last 24
hours) was on the original patch, not the updated one that you posted
later, which included the stack checking. I'm sure that I was having
the same problem with the overflow checking enabled and _not_ getting
any errors from it, but I'll redo the testing for my sanity's sake.
--
Dave Hansen
[email protected]
> I'm a little bit worried about this patch. Have you tried something
> like NFS-over-ext3-over-LVM-over-MD or so, which can have a deep stack?
No, I don't think we're that twisted.
But feel free ... and have fun getting LVM to work first ;-)
IMHO, bugfixing arcane corner-case bloat issues can come later, if all normal
configs work.
M.
On 2 October 2002 19:56, Andreas Dilger wrote:
> Alternately, you could set up an 8kB stack + IRQ stack and "red-zone"
> the high page of the current 8kB stack and see if it is ever used.
This debugging technique definitely works. Look how many sleeping calls
under locks apkm has caught recently!
--
vda