* [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks
@ 2004-03-16 6:35 Zwane Mwaikambo
2004-03-16 7:16 ` Ingo Molnar
2004-03-16 10:40 ` William Lee Irwin III
0 siblings, 2 replies; 4+ messages in thread
From: Zwane Mwaikambo @ 2004-03-16 6:35 UTC (permalink / raw)
To: Linux Kernel; +Cc: Ingo Molnar, Andrew Morton, Matt Mackall
The 4/4 code right now is setup for 8k stacks, this patch should allow for
arbitrary stack sizes. Some parts are rather ugly (e.g. STACK_PAGE_COUNT)
so (abusive too) comments are welcome.
I've tested it with 4k,8k and 16k stacks on UP and SMP, but i believe it
breaks with CONFIG_DEBUG_PAGEALLOC
Index: linux-2.6.4-mm2/include/asm-i386/fixmap.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/fixmap.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 fixmap.h
--- linux-2.6.4-mm2/include/asm-i386/fixmap.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
+++ linux-2.6.4-mm2/include/asm-i386/fixmap.h 15 Mar 2004 16:01:20 -0000
@@ -115,10 +115,10 @@ extern void __set_fixmap (enum fixed_add
* Leave one empty page between vmalloc'ed areas and
* the start of the fixmap.
*
- * IMPORTANT: dont change FIXADDR_TOP without adjusting KM_VSTACK0
- * and KM_VSTACK1 so that the virtual stack is 8K aligned.
+ * IMPORTANT: we have to align FIXADDR_TOP so that the virtual stack
+ * is THREAD_SIZE aligned.
*/
-#define FIXADDR_TOP (0xffffe000UL)
+#define FIXADDR_TOP (0xffffe000UL & ~(THREAD_SIZE-1))
#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
Index: linux-2.6.4-mm2/include/asm-i386/kmap_types.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/kmap_types.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 kmap_types.h
--- linux-2.6.4-mm2/include/asm-i386/kmap_types.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
+++ linux-2.6.4-mm2/include/asm-i386/kmap_types.h 15 Mar 2004 23:09:53 -0000
@@ -2,15 +2,16 @@
#define _ASM_KMAP_TYPES_H
#include <linux/config.h>
+#include <linux/thread_info.h>
enum km_type {
/*
- * IMPORTANT: don't move these 3 entries, and only add entries in
- * pairs: the 4G/4G virtual stack must be 8K aligned on each cpu.
+ * IMPORTANT: don't move these 3 entries, be wary when adding entries,
+ * the 4G/4G virtual stack must be THREAD_SIZE aligned on each cpu.
*/
KM_BOUNCE_READ,
- KM_VSTACK1,
- KM_VSTACK0,
+ KM_VSTACK_BASE,
+ KM_VSTACK_TOP = KM_VSTACK_BASE + STACK_PAGE_COUNT-1,
KM_LDT_PAGE15,
KM_LDT_PAGE0 = KM_LDT_PAGE15 + 16-1,
@@ -30,8 +31,8 @@ enum km_type {
KM_SOFTIRQ0,
KM_SOFTIRQ1,
/*
- * Add new entries in pairs:
- * the 4G/4G virtual stack must be 8K aligned on each cpu.
+ * Be wary when adding entries:
+ * the 4G/4G virtual stack must be THREAD_SIZE aligned on each cpu.
*/
KM_TYPE_NR
};
Index: linux-2.6.4-mm2/include/asm-i386/processor.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/processor.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 processor.h
--- linux-2.6.4-mm2/include/asm-i386/processor.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
+++ linux-2.6.4-mm2/include/asm-i386/processor.h 15 Mar 2004 15:44:57 -0000
@@ -401,10 +401,16 @@ struct tss_struct {
#define ARCH_MIN_TASKALIGN 16
+#ifdef CONFIG_4KSTACKS
+#define STACK_PAGE_COUNT (4096/PAGE_SIZE)
+#else
+#define STACK_PAGE_COUNT (8192/PAGE_SIZE) /* THREAD_SIZE/PAGE_SIZE */
+#endif
+
struct thread_struct {
/* cached TLS descriptors. */
struct desc_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
- void *stack_page0, *stack_page1;
+ void *stack_page[STACK_PAGE_COUNT];
unsigned long esp0;
unsigned long sysenter_cs;
unsigned long eip;
Index: linux-2.6.4-mm2/include/asm-i386/thread_info.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/thread_info.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 thread_info.h
--- linux-2.6.4-mm2/include/asm-i386/thread_info.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
+++ linux-2.6.4-mm2/include/asm-i386/thread_info.h 15 Mar 2004 15:49:56 -0000
@@ -49,8 +49,10 @@ struct thread_info {
#endif
#define PREEMPT_ACTIVE 0x4000000
+
+/* if you change THREAD_SIZE here, don't forget to change STACK_PAGE_COUNT */
#ifdef CONFIG_4KSTACKS
-#define THREAD_SIZE (4096)
+#define THREAD_SIZE (4096)
#else
#define THREAD_SIZE (8192)
#endif
Index: linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 entry_trampoline.c
--- linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c 15 Mar 2004 05:53:30 -0000 1.1.1.1
+++ linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c 15 Mar 2004 08:52:48 -0000
@@ -21,7 +21,9 @@ extern char __entry_tramp_start, __entry
void __init init_entry_mappings(void)
{
#ifdef CONFIG_X86_HIGH_ENTRY
+
void *tramp;
+ int p;
/*
* We need a high IDT and GDT for the 4G/4G split:
@@ -37,7 +39,7 @@ void __init init_entry_mappings(void)
/*
* Virtual kernel stack:
*/
- BUG_ON(__kmap_atomic_vaddr(KM_VSTACK0) & (THREAD_SIZE-1));
+ BUG_ON(__kmap_atomic_vaddr(KM_VSTACK_TOP) & (THREAD_SIZE-1));
BUG_ON(sizeof(struct desc_struct)*NR_CPUS*GDT_ENTRIES > 2*PAGE_SIZE);
BUG_ON((unsigned int)&__entry_tramp_end - (unsigned int)&__entry_tramp_start > 2*PAGE_SIZE);
@@ -45,15 +47,15 @@ void __init init_entry_mappings(void)
* set up the initial thread's virtual stack related
* fields:
*/
- current->thread.stack_page0 = virt_to_page((char *)current->thread_info);
- current->thread.stack_page1 = virt_to_page((char *)current->thread_info + PAGE_SIZE);
- current->thread_info->virtual_stack = (void *)__kmap_atomic_vaddr(KM_VSTACK0);
-
- __kunmap_atomic_type(KM_VSTACK0);
- __kunmap_atomic_type(KM_VSTACK1);
- __kmap_atomic(current->thread.stack_page0, KM_VSTACK0);
- __kmap_atomic(current->thread.stack_page1, KM_VSTACK1);
+ for (p = 0; p < ARRAY_SIZE(current->thread.stack_page); p++)
+ current->thread.stack_page[p] = virt_to_page((char *)current->thread_info + (p*PAGE_SIZE));
+
+ current->thread_info->virtual_stack = (void *)__kmap_atomic_vaddr(KM_VSTACK_TOP);
+ for (p = 0; p < ARRAY_SIZE(current->thread.stack_page); p++) {
+ __kunmap_atomic_type(KM_VSTACK_TOP-p);
+ __kmap_atomic(current->thread.stack_page[p], KM_VSTACK_TOP-p);
+ }
#endif
current->thread_info->real_stack = (void *)current->thread_info;
current->thread_info->user_pgd = NULL;
Index: linux-2.6.4-mm2/arch/i386/kernel/process.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.4-mm2/arch/i386/kernel/process.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 process.c
--- linux-2.6.4-mm2/arch/i386/kernel/process.c 15 Mar 2004 05:53:30 -0000 1.1.1.1
+++ linux-2.6.4-mm2/arch/i386/kernel/process.c 15 Mar 2004 08:08:42 -0000
@@ -345,7 +345,7 @@ int copy_thread(int nr, unsigned long cl
{
struct pt_regs * childregs;
struct task_struct *tsk;
- int err;
+ int err, i;
childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
struct_cpy(childregs, regs);
@@ -360,10 +360,11 @@ int copy_thread(int nr, unsigned long cl
* get the two stack pages, for the virtual stack.
*
* IMPORTANT: this code relies on the fact that the task
- * structure is an 8K aligned piece of physical memory.
+ * structure is an THREAD_SIZE aligned piece of physical memory.
*/
- p->thread.stack_page0 = virt_to_page((unsigned long)p->thread_info);
- p->thread.stack_page1 = virt_to_page((unsigned long)p->thread_info + PAGE_SIZE);
+ for (i = 0; i < ARRAY_SIZE(p->thread.stack_page); i++)
+ p->thread.stack_page[i] =
+ virt_to_page((unsigned long)p->thread_info + (i*PAGE_SIZE));
p->thread.eip = (unsigned long) ret_from_fork;
p->thread_info->real_stack = p->thread_info;
@@ -519,22 +520,23 @@ struct task_struct fastcall * __switch_t
__unlazy_fpu(prev_p);
#ifdef CONFIG_X86_HIGH_ENTRY
+{
+ int i;
/*
* Set the ptes of the virtual stack. (NOTE: a one-page TLB flush is
* needed because otherwise NMIs could interrupt the
* user-return code with a virtual stack and stale TLBs.)
*/
- __kunmap_atomic_type(KM_VSTACK0);
- __kunmap_atomic_type(KM_VSTACK1);
- __kmap_atomic(next->stack_page0, KM_VSTACK0);
- __kmap_atomic(next->stack_page1, KM_VSTACK1);
-
+ for (i = 0; i < ARRAY_SIZE(next->stack_page); i++) {
+ __kunmap_atomic_type(KM_VSTACK_TOP-i);
+ __kmap_atomic(next->stack_page[i], KM_VSTACK_TOP-i);
+ }
/*
* NOTE: here we rely on the task being the stack as well
*/
next_p->thread_info->virtual_stack =
- (void *)__kmap_atomic_vaddr(KM_VSTACK0);
-
+ (void *)__kmap_atomic_vaddr(KM_VSTACK_TOP);
+}
#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
/*
* If next was preempted on entry from userspace to kernel,
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks
2004-03-16 6:35 [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks Zwane Mwaikambo
@ 2004-03-16 7:16 ` Ingo Molnar
2004-03-16 10:40 ` William Lee Irwin III
1 sibling, 0 replies; 4+ messages in thread
From: Ingo Molnar @ 2004-03-16 7:16 UTC (permalink / raw)
To: Zwane Mwaikambo; +Cc: Linux Kernel, Andrew Morton, Matt Mackall
looks good to me!
Ingo
* Zwane Mwaikambo <zwane@linuxpower.ca> wrote:
> The 4/4 code right now is setup for 8k stacks, this patch should allow for
> arbitrary stack sizes. Some parts are rather ugly (e.g. STACK_PAGE_COUNT)
> so (abusive too) comments are welcome.
>
> I've tested it with 4k,8k and 16k stacks on UP and SMP, but i believe it
> breaks with CONFIG_DEBUG_PAGEALLOC
>
> Index: linux-2.6.4-mm2/include/asm-i386/fixmap.h
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/fixmap.h,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 fixmap.h
> --- linux-2.6.4-mm2/include/asm-i386/fixmap.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/include/asm-i386/fixmap.h 15 Mar 2004 16:01:20 -0000
> @@ -115,10 +115,10 @@ extern void __set_fixmap (enum fixed_add
> * Leave one empty page between vmalloc'ed areas and
> * the start of the fixmap.
> *
> - * IMPORTANT: dont change FIXADDR_TOP without adjusting KM_VSTACK0
> - * and KM_VSTACK1 so that the virtual stack is 8K aligned.
> + * IMPORTANT: we have to align FIXADDR_TOP so that the virtual stack
> + * is THREAD_SIZE aligned.
> */
> -#define FIXADDR_TOP (0xffffe000UL)
> +#define FIXADDR_TOP (0xffffe000UL & ~(THREAD_SIZE-1))
> #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
> #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
>
> Index: linux-2.6.4-mm2/include/asm-i386/kmap_types.h
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/kmap_types.h,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 kmap_types.h
> --- linux-2.6.4-mm2/include/asm-i386/kmap_types.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/include/asm-i386/kmap_types.h 15 Mar 2004 23:09:53 -0000
> @@ -2,15 +2,16 @@
> #define _ASM_KMAP_TYPES_H
>
> #include <linux/config.h>
> +#include <linux/thread_info.h>
>
> enum km_type {
> /*
> - * IMPORTANT: don't move these 3 entries, and only add entries in
> - * pairs: the 4G/4G virtual stack must be 8K aligned on each cpu.
> + * IMPORTANT: don't move these 3 entries, be wary when adding entries,
> + * the 4G/4G virtual stack must be THREAD_SIZE aligned on each cpu.
> */
> KM_BOUNCE_READ,
> - KM_VSTACK1,
> - KM_VSTACK0,
> + KM_VSTACK_BASE,
> + KM_VSTACK_TOP = KM_VSTACK_BASE + STACK_PAGE_COUNT-1,
>
> KM_LDT_PAGE15,
> KM_LDT_PAGE0 = KM_LDT_PAGE15 + 16-1,
> @@ -30,8 +31,8 @@ enum km_type {
> KM_SOFTIRQ0,
> KM_SOFTIRQ1,
> /*
> - * Add new entries in pairs:
> - * the 4G/4G virtual stack must be 8K aligned on each cpu.
> + * Be wary when adding entries:
> + * the 4G/4G virtual stack must be THREAD_SIZE aligned on each cpu.
> */
> KM_TYPE_NR
> };
> Index: linux-2.6.4-mm2/include/asm-i386/processor.h
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/processor.h,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 processor.h
> --- linux-2.6.4-mm2/include/asm-i386/processor.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/include/asm-i386/processor.h 15 Mar 2004 15:44:57 -0000
> @@ -401,10 +401,16 @@ struct tss_struct {
>
> #define ARCH_MIN_TASKALIGN 16
>
> +#ifdef CONFIG_4KSTACKS
> +#define STACK_PAGE_COUNT (4096/PAGE_SIZE)
> +#else
> +#define STACK_PAGE_COUNT (8192/PAGE_SIZE) /* THREAD_SIZE/PAGE_SIZE */
> +#endif
> +
> struct thread_struct {
> /* cached TLS descriptors. */
> struct desc_struct tls_array[GDT_ENTRY_TLS_ENTRIES];
> - void *stack_page0, *stack_page1;
> + void *stack_page[STACK_PAGE_COUNT];
> unsigned long esp0;
> unsigned long sysenter_cs;
> unsigned long eip;
> Index: linux-2.6.4-mm2/include/asm-i386/thread_info.h
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/include/asm-i386/thread_info.h,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 thread_info.h
> --- linux-2.6.4-mm2/include/asm-i386/thread_info.h 15 Mar 2004 05:53:41 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/include/asm-i386/thread_info.h 15 Mar 2004 15:49:56 -0000
> @@ -49,8 +49,10 @@ struct thread_info {
> #endif
>
> #define PREEMPT_ACTIVE 0x4000000
> +
> +/* if you change THREAD_SIZE here, don't forget to change STACK_PAGE_COUNT */
> #ifdef CONFIG_4KSTACKS
> -#define THREAD_SIZE (4096)
> +#define THREAD_SIZE (4096)
> #else
> #define THREAD_SIZE (8192)
> #endif
> Index: linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 entry_trampoline.c
> --- linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c 15 Mar 2004 05:53:30 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/arch/i386/kernel/entry_trampoline.c 15 Mar 2004 08:52:48 -0000
> @@ -21,7 +21,9 @@ extern char __entry_tramp_start, __entry
> void __init init_entry_mappings(void)
> {
> #ifdef CONFIG_X86_HIGH_ENTRY
> +
> void *tramp;
> + int p;
>
> /*
> * We need a high IDT and GDT for the 4G/4G split:
> @@ -37,7 +39,7 @@ void __init init_entry_mappings(void)
> /*
> * Virtual kernel stack:
> */
> - BUG_ON(__kmap_atomic_vaddr(KM_VSTACK0) & (THREAD_SIZE-1));
> + BUG_ON(__kmap_atomic_vaddr(KM_VSTACK_TOP) & (THREAD_SIZE-1));
> BUG_ON(sizeof(struct desc_struct)*NR_CPUS*GDT_ENTRIES > 2*PAGE_SIZE);
> BUG_ON((unsigned int)&__entry_tramp_end - (unsigned int)&__entry_tramp_start > 2*PAGE_SIZE);
>
> @@ -45,15 +47,15 @@ void __init init_entry_mappings(void)
> * set up the initial thread's virtual stack related
> * fields:
> */
> - current->thread.stack_page0 = virt_to_page((char *)current->thread_info);
> - current->thread.stack_page1 = virt_to_page((char *)current->thread_info + PAGE_SIZE);
> - current->thread_info->virtual_stack = (void *)__kmap_atomic_vaddr(KM_VSTACK0);
> -
> - __kunmap_atomic_type(KM_VSTACK0);
> - __kunmap_atomic_type(KM_VSTACK1);
> - __kmap_atomic(current->thread.stack_page0, KM_VSTACK0);
> - __kmap_atomic(current->thread.stack_page1, KM_VSTACK1);
> + for (p = 0; p < ARRAY_SIZE(current->thread.stack_page); p++)
> + current->thread.stack_page[p] = virt_to_page((char *)current->thread_info + (p*PAGE_SIZE));
> +
> + current->thread_info->virtual_stack = (void *)__kmap_atomic_vaddr(KM_VSTACK_TOP);
>
> + for (p = 0; p < ARRAY_SIZE(current->thread.stack_page); p++) {
> + __kunmap_atomic_type(KM_VSTACK_TOP-p);
> + __kmap_atomic(current->thread.stack_page[p], KM_VSTACK_TOP-p);
> + }
> #endif
> current->thread_info->real_stack = (void *)current->thread_info;
> current->thread_info->user_pgd = NULL;
> Index: linux-2.6.4-mm2/arch/i386/kernel/process.c
> ===================================================================
> RCS file: /home/cvsroot/linux-2.6.4-mm2/arch/i386/kernel/process.c,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 process.c
> --- linux-2.6.4-mm2/arch/i386/kernel/process.c 15 Mar 2004 05:53:30 -0000 1.1.1.1
> +++ linux-2.6.4-mm2/arch/i386/kernel/process.c 15 Mar 2004 08:08:42 -0000
> @@ -345,7 +345,7 @@ int copy_thread(int nr, unsigned long cl
> {
> struct pt_regs * childregs;
> struct task_struct *tsk;
> - int err;
> + int err, i;
>
> childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
> struct_cpy(childregs, regs);
> @@ -360,10 +360,11 @@ int copy_thread(int nr, unsigned long cl
> * get the two stack pages, for the virtual stack.
> *
> * IMPORTANT: this code relies on the fact that the task
> - * structure is an 8K aligned piece of physical memory.
> + * structure is an THREAD_SIZE aligned piece of physical memory.
> */
> - p->thread.stack_page0 = virt_to_page((unsigned long)p->thread_info);
> - p->thread.stack_page1 = virt_to_page((unsigned long)p->thread_info + PAGE_SIZE);
> + for (i = 0; i < ARRAY_SIZE(p->thread.stack_page); i++)
> + p->thread.stack_page[i] =
> + virt_to_page((unsigned long)p->thread_info + (i*PAGE_SIZE));
>
> p->thread.eip = (unsigned long) ret_from_fork;
> p->thread_info->real_stack = p->thread_info;
> @@ -519,22 +520,23 @@ struct task_struct fastcall * __switch_t
> __unlazy_fpu(prev_p);
>
> #ifdef CONFIG_X86_HIGH_ENTRY
> +{
> + int i;
> /*
> * Set the ptes of the virtual stack. (NOTE: a one-page TLB flush is
> * needed because otherwise NMIs could interrupt the
> * user-return code with a virtual stack and stale TLBs.)
> */
> - __kunmap_atomic_type(KM_VSTACK0);
> - __kunmap_atomic_type(KM_VSTACK1);
> - __kmap_atomic(next->stack_page0, KM_VSTACK0);
> - __kmap_atomic(next->stack_page1, KM_VSTACK1);
> -
> + for (i = 0; i < ARRAY_SIZE(next->stack_page); i++) {
> + __kunmap_atomic_type(KM_VSTACK_TOP-i);
> + __kmap_atomic(next->stack_page[i], KM_VSTACK_TOP-i);
> + }
> /*
> * NOTE: here we rely on the task being the stack as well
> */
> next_p->thread_info->virtual_stack =
> - (void *)__kmap_atomic_vaddr(KM_VSTACK0);
> -
> + (void *)__kmap_atomic_vaddr(KM_VSTACK_TOP);
> +}
> #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
> /*
> * If next was preempted on entry from userspace to kernel,
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks
2004-03-16 6:35 [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks Zwane Mwaikambo
2004-03-16 7:16 ` Ingo Molnar
@ 2004-03-16 10:40 ` William Lee Irwin III
2004-03-16 17:08 ` Zwane Mwaikambo
1 sibling, 1 reply; 4+ messages in thread
From: William Lee Irwin III @ 2004-03-16 10:40 UTC (permalink / raw)
To: Zwane Mwaikambo; +Cc: Linux Kernel, Ingo Molnar, Andrew Morton, Matt Mackall
On Tue, Mar 16, 2004 at 01:35:36AM -0500, Zwane Mwaikambo wrote:
> +#ifdef CONFIG_4KSTACKS
> +#define STACK_PAGE_COUNT (4096/PAGE_SIZE)
> +#else
> +#define STACK_PAGE_COUNT (8192/PAGE_SIZE) /* THREAD_SIZE/PAGE_SIZE */
> +#endif
This looks like it wants to be:
#define STACK_PAGE_COUNT (PAGE_ALIGN(THREAD_SIZE)/PAGE_SIZE)
(There are reasons to want THREAD_SIZE < PAGE_SIZE having to do with
elevating PAGE_SIZE as opposed to shrinking THREAD_SIZE outright.)
It looks like kmap_types.h should inherits PAGE_* from processor.h
which in turn should inherit them from page.h
Did the headers barf on this or something? I can't imagine you didn't
think of it already.
-- wli
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks
2004-03-16 10:40 ` William Lee Irwin III
@ 2004-03-16 17:08 ` Zwane Mwaikambo
0 siblings, 0 replies; 4+ messages in thread
From: Zwane Mwaikambo @ 2004-03-16 17:08 UTC (permalink / raw)
To: William Lee Irwin III
Cc: Linux Kernel, Ingo Molnar, Andrew Morton, Matt Mackall
On Tue, 16 Mar 2004, William Lee Irwin III wrote:
> On Tue, Mar 16, 2004 at 01:35:36AM -0500, Zwane Mwaikambo wrote:
> > +#ifdef CONFIG_4KSTACKS
> > +#define STACK_PAGE_COUNT (4096/PAGE_SIZE)
> > +#else
> > +#define STACK_PAGE_COUNT (8192/PAGE_SIZE) /* THREAD_SIZE/PAGE_SIZE */
> > +#endif
>
> This looks like it wants to be:
>
> #define STACK_PAGE_COUNT (PAGE_ALIGN(THREAD_SIZE)/PAGE_SIZE)
>
> (There are reasons to want THREAD_SIZE < PAGE_SIZE having to do with
> elevating PAGE_SIZE as opposed to shrinking THREAD_SIZE outright.)
Ah yes, i forgot about that case thanks for pointing it out.
> It looks like kmap_types.h should inherits PAGE_* from processor.h
> which in turn should inherit them from page.h
>
> Did the headers barf on this or something? I can't imagine you didn't
> think of it already.
Yes it does inherit PAGE_*, but i needed to specify the same thing in
processor.h so i made it one define to make grepping easier and the
intention more obvious.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2004-03-16 6:35 [PATCH][2.6-mm] Fix 4G/4G w/ 8k+ stacks Zwane Mwaikambo
2004-03-16 7:16 ` Ingo Molnar
2004-03-16 10:40 ` William Lee Irwin III
2004-03-16 17:08 ` Zwane Mwaikambo
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