* [PATCH] to support hookable flush_tlb* functions
@ 2003-01-24 14:24 Thomas Schlichter
2003-01-24 21:21 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: Thomas Schlichter @ 2003-01-24 14:24 UTC (permalink / raw)
To: linux-kernel, torvalds; +Cc: Patrick R. Schulz
[-- Attachment #1: Type: text/plain, Size: 1717 bytes --]
Hello,
with this mail I send a patch that allows kernel modules to hook into the
different flush_tlb* functions defined in <asm/tlbflush.h> or <asm/pgtable.h> in
order to synchronize devices TLBs.
This is necessary for devices that provide their own TLB and cannot participate
on the CPU busses shootdown protocol. With this patch it is possible to assure
TLB consistency.
Currently this extension could possibly be used by high performance
interconnects like QsNet from Quadrics (www.quadrics.com), and in the near
future by even more high performance, low latency NICs that will implement
direct user space DMA transfers to not pinned user pages. TLBs are there a
mandatory requirement.
Currently I am writing my diploma thesis about the development of such a device
where I need this patch, and as it looks good to me I want to provide it to the
public community so it can be reviewed and even more tested. (the i386 parts are
tested work fine for me)
The patch consists of two parts, one generic part and for each supported
architecture an other part that depends on the generic one.
Attached to this mail is only the generic part and the architecture dependend
part for i386 compatible machines just not to waste everyones bandwidth... But
if requested I can send you patches for the other architectures, too.
The i386 patch also includes some cleanups by renaming __flush_tlb_* to
local_flush_tlb_*.
I hope some time this patches will make it into the kernel sources. (perhaps
even into 2.6.x ?)
Sincerely yours
Thomas Schlichter
P.S.: To test this patch I've also written a module that counts the different
flush_tlb* calls and shows them in /proc/tlbstat. If requested I could send you
this, too.
[-- Attachment #2: tlbhook_generic.patch --]
[-- Type: application/octet-stream, Size: 5106 bytes --]
diff -urP linux-2.5.59/include/linux/tlbhook.h linux-2.5.59_patched/include/linux/tlbhook.h
--- linux-2.5.59/include/linux/tlbhook.h Thu Jan 1 01:00:00 1970
+++ linux-2.5.59_patched/include/linux/tlbhook.h Wed Jan 22 22:29:30 2003
@@ -0,0 +1,122 @@
+#ifndef _LINUX_TLBHOOK_H
+#define _LINUX_TLBHOOK_H
+
+#include <linux/mm.h>
+
+typedef struct tlb_hook_struct {
+ void (*flush_tlb)( void );
+ void (*flush_tlb_all)( void );
+ void (*flush_tlb_mm)( struct mm_struct *mm );
+ void (*flush_tlb_page)( struct vm_area_struct *vma,
+ unsigned long addr );
+ void (*flush_tlb_range)( struct vm_area_struct *vma,
+ unsigned long start, unsigned long end );
+ void (*flush_tlb_kernel_range)( unsigned long start,
+ unsigned long end );
+ void (*flush_tlb_pgtables)( struct mm_struct *mm,
+ unsigned long start, unsigned long end );
+
+ struct tlb_hook_struct *next;
+ struct tlb_hook_struct *last;
+} tlb_hook_t;
+
+extern tlb_hook_t *tlb_hook_root;
+
+extern int register_tlb_hook( tlb_hook_t *hook );
+extern int unregister_tlb_hook( tlb_hook_t *hook );
+
+static inline void flush_tlb_hook( void )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb )
+ hook->flush_tlb( );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_all_hook( void )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb_all )
+ hook->flush_tlb_all( );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_mm_hook( struct mm_struct *mm )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb_mm )
+ hook->flush_tlb_mm( mm );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_page_hook( struct vm_area_struct *vma,
+ unsigned long addr )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb_page )
+ hook->flush_tlb_page( vma, addr );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_range_hook( struct vm_area_struct *vma,
+ unsigned long start, unsigned long end )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb_range )
+ hook->flush_tlb_range( vma, start, end );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_kernel_range_hook( unsigned long start,
+ unsigned long end )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook)
+ {
+ if( hook->flush_tlb_kernel_range )
+ hook->flush_tlb_kernel_range( start, end );
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_pgtables_hook( struct mm_struct *mm,
+ unsigned long start, unsigned long end )
+{
+ tlb_hook_t *hook = tlb_hook_root;
+
+ while( hook )
+ {
+ if( hook->flush_tlb_pgtables )
+ hook->flush_tlb_pgtables( mm, start, end );
+ hook = hook->next;
+ }
+}
+
+#endif /* _LINUX_TLBHOOK_H */
diff -urP linux-2.5.59/mm/Makefile linux-2.5.59_patched/mm/Makefile
--- linux-2.5.59/mm/Makefile Fri Jan 17 03:22:20 2003
+++ linux-2.5.59_patched/mm/Makefile Wed Jan 22 22:34:06 2003
@@ -2,7 +2,8 @@
# Makefile for the linux memory manager.
#
-export-objs := shmem.o filemap.o mempool.o page_alloc.o page-writeback.o
+export-objs := shmem.o filemap.o mempool.o page_alloc.o page-writeback.o \
+ tlbhook.o
mmu-y := nommu.o
mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
@@ -11,6 +12,6 @@
obj-y := bootmem.o filemap.o mempool.o oom_kill.o \
page_alloc.o page-writeback.o pdflush.o readahead.o \
- slab.o swap.o truncate.o vcache.o vmscan.o $(mmu-y)
+ slab.o swap.o tlbhook.o truncate.o vcache.o vmscan.o $(mmu-y)
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o
diff -urP linux-2.5.59/mm/tlbhook.c linux-2.5.59_patched/mm/tlbhook.c
--- linux-2.5.59/mm/tlbhook.c Thu Jan 1 01:00:00 1970
+++ linux-2.5.59_patched/mm/tlbhook.c Wed Jan 22 22:38:42 2003
@@ -0,0 +1,70 @@
+#include <linux/module.h>
+#include <linux/tlbhook.h>
+
+static spinlock_t tlb_hook_lock = SPIN_LOCK_UNLOCKED;
+
+tlb_hook_t *tlb_hook_root = NULL;
+
+
+/* register hooks for the flush_tlb* functions */
+int register_tlb_hook( tlb_hook_t *hook )
+{
+ tlb_hook_t *last;
+
+ if( !hook )
+ return -EINVAL;
+
+ hook->next = NULL;
+
+ // lock the tlb_hook_struct to avoid race conditions
+ spin_lock( &tlb_hook_lock );
+
+ if( tlb_hook_root )
+ {
+ last = tlb_hook_root->last;
+ tlb_hook_root->last = hook;
+
+ hook->last = last;
+ last->next = hook;
+ } else {
+ hook->last = hook;
+ tlb_hook_root = hook;
+ }
+
+ spin_unlock( &tlb_hook_lock );
+
+ return 0;
+}
+
+
+/* unregister hooks for the flush_tlb* functions */
+int unregister_tlb_hook( tlb_hook_t *hook )
+{
+ if( !hook )
+ return -EINVAL;
+
+ // lock the tlb_hook_struct to avoid race conditions
+ spin_lock( &tlb_hook_lock );
+
+ if( hook == tlb_hook_root )
+ {
+ tlb_hook_root = hook->next;
+ } else {
+ hook->last->next = hook->next;
+ }
+
+ if( hook->next )
+ {
+ hook->next->last = hook->last;
+ } else if( tlb_hook_root ) {
+ tlb_hook_root->last = hook->last;
+ }
+
+ spin_unlock( &tlb_hook_lock );
+
+ return 0;
+}
+
+
+EXPORT_SYMBOL( register_tlb_hook );
+EXPORT_SYMBOL( unregister_tlb_hook );
[-- Attachment #3: tlbhook_i386.patch --]
[-- Type: application/octet-stream, Size: 9481 bytes --]
diff -urP linux-2.5.59/arch/i386/kernel/smp.c linux-2.5.59_patched/arch/i386/kernel/smp.c
--- linux-2.5.59/arch/i386/kernel/smp.c Fri Jan 17 03:21:38 2003
+++ linux-2.5.59_patched/arch/i386/kernel/smp.c Wed Jan 22 23:19:45 2003
@@ -327,7 +327,7 @@
if (flush_va == FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(flush_va);
+ local_flush_tlb_one(flush_va);
} else
leave_mm(cpu);
}
@@ -382,7 +382,7 @@
spin_unlock(&tlbstate_lock);
}
-void flush_tlb_current_task(void)
+void smp_flush_tlb(void)
{
struct mm_struct *mm = current->mm;
unsigned long cpu_mask;
@@ -396,7 +396,7 @@
preempt_enable();
}
-void flush_tlb_mm (struct mm_struct * mm)
+void smp_flush_tlb_mm (struct mm_struct * mm)
{
unsigned long cpu_mask;
@@ -415,7 +415,7 @@
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
+void smp_flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long cpu_mask;
@@ -425,7 +425,7 @@
if (current->active_mm == mm) {
if(current->mm)
- __flush_tlb_one(va);
+ local_flush_tlb_one(va);
else
leave_mm(smp_processor_id());
}
@@ -440,7 +440,7 @@
{
unsigned long cpu = smp_processor_id();
- __flush_tlb_all();
+ local_flush_tlb_all();
if (cpu_tlbstate[cpu].state == TLBSTATE_LAZY)
leave_mm(cpu);
}
@@ -450,7 +450,7 @@
do_flush_tlb_all_local();
}
-void flush_tlb_all(void)
+void smp_flush_tlb_all(void)
{
smp_call_function (flush_tlb_all_ipi,0,1,1);
diff -urP linux-2.5.59/arch/i386/mach-voyager/voyager_smp.c linux-2.5.59_patched/arch/i386/mach-voyager/voyager_smp.c
--- linux-2.5.59/arch/i386/mach-voyager/voyager_smp.c Fri Jan 17 03:22:02 2003
+++ linux-2.5.59_patched/arch/i386/mach-voyager/voyager_smp.c Wed Jan 22 23:18:03 2003
@@ -892,7 +892,7 @@
if (flush_va == FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(flush_va);
+ local_flush_tlb_one(flush_va);
} else
leave_mm(cpu);
}
@@ -948,7 +948,7 @@
}
void
-flush_tlb_current_task(void)
+smp_flush_tlb(void)
{
struct mm_struct *mm = current->mm;
unsigned long cpu_mask;
@@ -965,7 +965,7 @@
void
-flush_tlb_mm (struct mm_struct * mm)
+smp_flush_tlb_mm (struct mm_struct * mm)
{
unsigned long cpu_mask;
@@ -985,7 +985,7 @@
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
+void smp_flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long cpu_mask;
@@ -995,7 +995,7 @@
cpu_mask = mm->cpu_vm_mask & ~(1 << smp_processor_id());
if (current->active_mm == mm) {
if(current->mm)
- __flush_tlb_one(va);
+ local_flush_tlb_one(va);
else
leave_mm(smp_processor_id());
}
@@ -1217,7 +1217,7 @@
{
unsigned long cpu = smp_processor_id();
- __flush_tlb_all();
+ local_flush_tlb_all();
if (cpu_tlbstate[cpu].state == TLBSTATE_LAZY)
leave_mm(cpu);
}
@@ -1231,7 +1231,7 @@
/* flush the TLB of every active CPU in the system */
void
-flush_tlb_all(void)
+smp_flush_tlb_all(void)
{
smp_call_function (flush_tlb_all_function, 0, 1, 1);
diff -urP linux-2.5.59/arch/i386/mm/highmem.c linux-2.5.59_patched/arch/i386/mm/highmem.c
--- linux-2.5.59/arch/i386/mm/highmem.c Fri Jan 17 03:22:14 2003
+++ linux-2.5.59_patched/arch/i386/mm/highmem.c Wed Jan 22 23:14:33 2003
@@ -42,7 +42,7 @@
BUG();
#endif
set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
return (void*) vaddr;
}
@@ -66,7 +66,7 @@
* this pte without first remap it
*/
pte_clear(kmap_pte-idx);
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
#endif
dec_preempt_count();
diff -urP linux-2.5.59/arch/i386/mm/init.c linux-2.5.59_patched/arch/i386/mm/init.c
--- linux-2.5.59/arch/i386/mm/init.c Fri Jan 17 03:22:27 2003
+++ linux-2.5.59_patched/arch/i386/mm/init.c Wed Jan 22 23:15:05 2003
@@ -369,7 +369,7 @@
if (cpu_has_pae)
set_in_cr4(X86_CR4_PAE);
#endif
- __flush_tlb_all();
+ local_flush_tlb_all();
kmap_init();
zone_sizes_init();
diff -urP linux-2.5.59/arch/i386/mm/pageattr.c linux-2.5.59_patched/arch/i386/mm/pageattr.c
--- linux-2.5.59/arch/i386/mm/pageattr.c Fri Jan 17 03:22:04 2003
+++ linux-2.5.59_patched/arch/i386/mm/pageattr.c Wed Jan 22 23:14:01 2003
@@ -53,7 +53,7 @@
/* Flush all to work around Errata in early athlons regarding
* large page flushing.
*/
- __flush_tlb_all();
+ local_flush_tlb_all();
}
static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
diff -urP linux-2.5.59/arch/i386/mm/pgtable.c linux-2.5.59_patched/arch/i386/mm/pgtable.c
--- linux-2.5.59/arch/i386/mm/pgtable.c Fri Jan 17 03:23:01 2003
+++ linux-2.5.59_patched/arch/i386/mm/pgtable.c Wed Jan 22 23:15:32 2003
@@ -81,7 +81,7 @@
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
}
/*
@@ -114,7 +114,7 @@
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
}
void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
diff -urP linux-2.5.59/include/asm-i386/tlbflush.h linux-2.5.59_patched/include/asm-i386/tlbflush.h
--- linux-2.5.59/include/asm-i386/tlbflush.h Fri Jan 17 03:22:49 2003
+++ linux-2.5.59_patched/include/asm-i386/tlbflush.h Wed Jan 22 23:12:10 2003
@@ -2,10 +2,10 @@
#define _I386_TLBFLUSH_H
#include <linux/config.h>
-#include <linux/mm.h>
+#include <linux/tlbhook.h>
#include <asm/processor.h>
-#define __flush_tlb() \
+#define local_flush_tlb() \
do { \
unsigned int tmpreg; \
\
@@ -37,12 +37,12 @@
extern unsigned long pgkern_mask;
-# define __flush_tlb_all() \
+# define local_flush_tlb_all() \
do { \
if (cpu_has_pge) \
__flush_tlb_global(); \
else \
- __flush_tlb(); \
+ local_flush_tlb(); \
} while (0)
#define cpu_has_invlpg (boot_cpu_data.x86 > 3)
@@ -51,14 +51,14 @@
__asm__ __volatile__("invlpg %0": :"m" (*(char *) addr))
#ifdef CONFIG_X86_INVLPG
-# define __flush_tlb_one(addr) __flush_tlb_single(addr)
+# define local_flush_tlb_one(addr) __flush_tlb_single(addr)
#else
-# define __flush_tlb_one(addr) \
+# define local_flush_tlb_one(addr) \
do { \
if (cpu_has_invlpg) \
__flush_tlb_single(addr); \
else \
- __flush_tlb(); \
+ local_flush_tlb(); \
} while (0)
#endif
@@ -79,47 +79,94 @@
#ifndef CONFIG_SMP
-#define flush_tlb() __flush_tlb()
-#define flush_tlb_all() __flush_tlb_all()
-#define local_flush_tlb() __flush_tlb()
+static inline void flush_tlb(void)
+{
+ flush_tlb_hook();
+ local_flush_tlb();
+}
+
+static inline void flush_tlb_all(void)
+{
+ flush_tlb_all_hook();
+ local_flush_tlb_all();
+}
static inline void flush_tlb_mm(struct mm_struct *mm)
{
+ flush_tlb_mm_hook(mm);
if (mm == current->active_mm)
- __flush_tlb();
+ local_flush_tlb();
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
+ flush_tlb_page_hook(vma, addr);
if (vma->vm_mm == current->active_mm)
- __flush_tlb_one(addr);
+ local_flush_tlb_one(addr);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
+ flush_tlb_range_hook(vma, start, end);
if (vma->vm_mm == current->active_mm)
- __flush_tlb();
+ local_flush_tlb();
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+ unsigned long end)
+{
+ flush_tlb_kernel_range_hook(start, end);
+ local_flush_tlb_all();
}
#else
#include <asm/smp.h>
-#define local_flush_tlb() \
- __flush_tlb()
+extern void smp_flush_tlb(void);
+extern void smp_flush_tlb_all(void);
+extern void smp_flush_tlb_mm(struct mm_struct *);
+extern void smp_flush_tlb_page(struct vm_area_struct *, unsigned long);
+
+static inline void flush_tlb(void)
+{
+ flush_tlb_hook();
+ smp_flush_tlb();
+}
+
+static inline void flush_tlb_all(void)
+{
+ flush_tlb_all_hook();
+ smp_flush_tlb_all();
+}
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+ flush_tlb_mm_hook(mm);
+ smp_flush_tlb_mm(mm);
+}
-extern void flush_tlb_all(void);
-extern void flush_tlb_current_task(void);
-extern void flush_tlb_mm(struct mm_struct *);
-extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ flush_tlb_page_hook(vma, addr);
+ smp_flush_tlb_page(vma, addr);
+}
-#define flush_tlb() flush_tlb_current_task()
+static inline void flush_tlb_range(struct vm_area_struct * vma,
+ unsigned long start, unsigned long end)
+{
+ flush_tlb_range_hook(vma, start, end);
+ smp_flush_tlb_mm(vma->vm_mm);
+}
-static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long start, unsigned long end)
+static inline void flush_tlb_kernel_range(unsigned long start,
+ unsigned long end)
{
- flush_tlb_mm(vma->vm_mm);
+ flush_tlb_kernel_range_hook(start, end);
+ smp_flush_tlb_all();
}
#define TLBSTATE_OK 1
@@ -136,11 +183,10 @@
#endif
-#define flush_tlb_kernel_range(start, end) flush_tlb_all()
-
static inline void flush_tlb_pgtables(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
+ flush_tlb_pgtables_hook(mm, start, end);
/* i386 does not keep any page table caches in TLB */
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] to support hookable flush_tlb* functions
2003-01-24 14:24 [PATCH] to support hookable flush_tlb* functions Thomas Schlichter
@ 2003-01-24 21:21 ` Andrew Morton
2003-01-24 22:39 ` David S. Miller
2003-01-26 23:30 ` Thomas Schlichter
0 siblings, 2 replies; 4+ messages in thread
From: Andrew Morton @ 2003-01-24 21:21 UTC (permalink / raw)
To: Thomas Schlichter; +Cc: linux-kernel, torvalds, schulz
Thomas Schlichter <schlicht@rumms.uni-mannheim.de> wrote:
>
> Hello,
>
> with this mail I send a patch that allows kernel modules to hook into the
> different flush_tlb* functions defined in <asm/tlbflush.h> or <asm/pgtable.h> in
> order to synchronize devices TLBs.
Looks sensible enough.
A few coding-style nits:
+typedef struct tlb_hook_struct {
+...
+} tlb_hook_t;
typedefs are unpopular. Please just use
struct tlb_hook {
...
};
+static inline void flush_tlb_hook( void )
extraneous whitespace - Linus style is flush_tlb_hook(void)
+ while( hook )
while (hook)
+ {
+ if( hook->flush_tlb )
if (hook->flush_tlb)
+ hook->flush_tlb( );
hook->flush_tlb();
etc...
The unregister_hook implementation is racy - the hook could be in use on
another CPU. That's OK - we have the RCU infrastructure which will allow
hooks to be torn down safely. And nice people who can help others who are
using that code.
> The i386 patch also includes some cleanups by renaming __flush_tlb_* to
> local_flush_tlb_*.
That makes plenty of sense.
> I hope some time this patches will make it into the kernel sources. (perhaps
> even into 2.6.x ?)
Well the big questions are: where are the drivers for these devices? When
can we expect to see significant demand for these devices? Will there be
significant demand across the lifetime of the 2.6 kernel?
BTW, when you say "low latency NICs that will implement direct user space DMA
transfers to not pinned user pages", what do you mean by "not pinned"?
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] to support hookable flush_tlb* functions
2003-01-24 21:21 ` Andrew Morton
@ 2003-01-24 22:39 ` David S. Miller
2003-01-26 23:30 ` Thomas Schlichter
1 sibling, 0 replies; 4+ messages in thread
From: David S. Miller @ 2003-01-24 22:39 UTC (permalink / raw)
To: Andrew Morton; +Cc: Thomas Schlichter, linux-kernel, torvalds, schulz
On Fri, 2003-01-24 at 13:21, Andrew Morton wrote:
> Well the big questions are: where are the drivers for these devices?
Andrew, have a look at:
http://www.dolphinics.com/support/os/source.html
it is possibly the most popular example.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] to support hookable flush_tlb* functions
2003-01-24 21:21 ` Andrew Morton
2003-01-24 22:39 ` David S. Miller
@ 2003-01-26 23:30 ` Thomas Schlichter
1 sibling, 0 replies; 4+ messages in thread
From: Thomas Schlichter @ 2003-01-26 23:30 UTC (permalink / raw)
To: Andrew Morton, Ingo Oeser; +Cc: linux-kernel, torvalds, schulz
[-- Attachment #1: Type: text/plain, Size: 2606 bytes --]
Hi,
24. Jan. 2003 22:21, Andrew Morton wrote:
> A few coding-style nits:
>
> +typedef struct tlb_hook_struct {
> +...
> +} tlb_hook_t;
>
> typedefs are unpopular. Please just use
>
> struct tlb_hook {
> ...
> };
>
> +static inline void flush_tlb_hook( void )
>
> extraneous whitespace - Linus style is flush_tlb_hook(void)
>
> + while( hook )
>
> while (hook)
>
> + {
> + if( hook->flush_tlb )
>
> if (hook->flush_tlb)
>
> + hook->flush_tlb( );
>
> hook->flush_tlb();
>
> etc...
Thanks for these nits, they should be fixed in the new attached version of the
patches...
> The unregister_hook implementation is racy - the hook could be in use on
> another CPU. That's OK - we have the RCU infrastructure which will allow
> hooks to be torn down safely. And nice people who can help others who are
> using that code.
I do not know what you ment with the RCU infrastructure, but the
unregister-race should be fixed in the new patches, I hope...
> > The i386 patch also includes some cleanups by renaming __flush_tlb_* to
> > local_flush_tlb_*.
>
> That makes plenty of sense.
Fine... ;-)
> > I hope some time this patches will make it into the kernel sources.
> > (perhaps even into 2.6.x ?)
>
> Well the big questions are: where are the drivers for these devices? When
> can we expect to see significant demand for these devices? Will there be
> significant demand across the lifetime of the 2.6 kernel?
Well, I cannot say this for sure as we just do universitary research, but I
really think this may be interesting even for companies which already create
their own kernel patches for existing products...
> BTW, when you say "low latency NICs that will implement direct user space
> DMA transfers to not pinned user pages", what do you mean by "not pinned"?
Well, with "not pinned" I mean the users memory pages need not to be pinned
before the transfer begins...
If the pages are not present they have to be swapped in by the kernel and be
pinned for the transfer, else the NIC may pin the page itself and start the
transfer.
The address translation may be performed directly from the network device or
via an interrupt in the kernel. The translation is then stored in the devices
TLB which may be flushed when the page is unpinned (then this patch is not
neccessary) or just if the translation is invalidated from the kernel (then
this patch is neccessary).
The second approach has the advantage that the TLB hit ratio can be improved
without having many user-pages pinned, and so removed from the memory pool,
for a long time...
Regards
Thomas Schlichter
[-- Attachment #2: tlbhook_generic.patch --]
[-- Type: text/x-diff, Size: 5437 bytes --]
diff -urP linux-2.5.59/include/linux/tlbhook.h linux-2.5.59_patched/include/linux/tlbhook.h
--- linux-2.5.59/include/linux/tlbhook.h Thu Jan 1 01:00:00 1970
+++ linux-2.5.59_patched/include/linux/tlbhook.h Sat Jan 25 10:33:51 2003
@@ -0,0 +1,151 @@
+#ifndef _LINUX_TLBHOOK_H
+#define _LINUX_TLBHOOK_H
+
+#include <linux/mm.h>
+
+struct tlb_hook_struct {
+ void (*flush_tlb)(void);
+ void (*flush_tlb_all)(void);
+ void (*flush_tlb_mm)(struct mm_struct *mm);
+ void (*flush_tlb_page)(struct vm_area_struct *vma,
+ unsigned long addr);
+ void (*flush_tlb_range)(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end);
+ void (*flush_tlb_kernel_range)(unsigned long start,
+ unsigned long end);
+ void (*flush_tlb_pgtables)(struct mm_struct *mm,
+ unsigned long start, unsigned long end);
+
+ struct tlb_hook_struct *next;
+ struct tlb_hook_struct *last;
+ volatile int used;
+};
+
+extern struct tlb_hook_struct *tlb_hook_root;
+
+extern int register_tlb_hook(struct tlb_hook_struct *hook);
+extern int unregister_tlb_hook(struct tlb_hook_struct *hook);
+
+static inline void flush_tlb_hook(void)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb)
+ {
+ hook->used = 1;
+ hook->flush_tlb();
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_all_hook(void)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_all)
+ {
+ hook->used = 1;
+ hook->flush_tlb_all();
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_mm_hook(struct mm_struct *mm)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_mm)
+ {
+ hook->used = 1;
+ hook->flush_tlb_mm(mm);
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_page_hook(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_page)
+ {
+ hook->used = 1;
+ hook->flush_tlb_page(vma, addr);
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_range_hook(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_range)
+ {
+ hook->used = 1;
+ hook->flush_tlb_range(vma, start, end);
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_kernel_range_hook(unsigned long start,
+ unsigned long end)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_kernel_range)
+ {
+ hook->used = 1;
+ hook->flush_tlb_kernel_range(start, end);
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+
+static inline void flush_tlb_pgtables_hook(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ struct tlb_hook_struct *hook = tlb_hook_root;
+
+ while(hook)
+ {
+ if(hook->flush_tlb_pgtables)
+ {
+ hook->used = 1;
+ hook->flush_tlb_pgtables(mm, start, end);
+ hook->used = 0;
+ }
+ hook = hook->next;
+ }
+}
+
+#endif /* _LINUX_TLBHOOK_H */
diff -urP linux-2.5.59/mm/Makefile linux-2.5.59_patched/mm/Makefile
--- linux-2.5.59/mm/Makefile Fri Jan 17 03:22:20 2003
+++ linux-2.5.59_patched/mm/Makefile Sat Jan 25 03:45:01 2003
@@ -2,7 +2,8 @@
# Makefile for the linux memory manager.
#
-export-objs := shmem.o filemap.o mempool.o page_alloc.o page-writeback.o
+export-objs := shmem.o filemap.o mempool.o page_alloc.o page-writeback.o \
+ tlbhook.o
mmu-y := nommu.o
mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \
@@ -11,6 +12,6 @@
obj-y := bootmem.o filemap.o mempool.o oom_kill.o \
page_alloc.o page-writeback.o pdflush.o readahead.o \
- slab.o swap.o truncate.o vcache.o vmscan.o $(mmu-y)
+ slab.o swap.o tlbhook.o truncate.o vcache.o vmscan.o $(mmu-y)
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o
diff -urP linux-2.5.59/mm/tlbhook.c linux-2.5.59_patched/mm/tlbhook.c
--- linux-2.5.59/mm/tlbhook.c Thu Jan 1 01:00:00 1970
+++ linux-2.5.59_patched/mm/tlbhook.c Sat Jan 25 10:43:33 2003
@@ -0,0 +1,68 @@
+#include <linux/module.h>
+#include <linux/tlbhook.h>
+
+static spinlock_t tlb_hook_lock = SPIN_LOCK_UNLOCKED;
+
+struct tlb_hook_struct *tlb_hook_root = NULL;
+
+
+/* register hooks for the flush_tlb* functions */
+int register_tlb_hook(struct tlb_hook_struct *hook)
+{
+ if(!hook)
+ return -EINVAL;
+
+ hook->last = NULL;
+ hook->used = 0;
+
+ // lock the tlb_hook_struct to avoid race conditions
+ spin_lock(&tlb_hook_lock);
+
+ hook->next = tlb_hook_root;
+ if(tlb_hook_root)
+ {
+ tlb_hook_root->last = hook;
+ }
+ tlb_hook_root = hook;
+
+ spin_unlock(&tlb_hook_lock);
+
+ return 0;
+}
+
+
+/* unregister hooks for the flush_tlb* functions */
+int unregister_tlb_hook(struct tlb_hook_struct *hook)
+{
+ if(!hook)
+ return -EINVAL;
+
+ // lock the tlb_hook_struct to avoid race conditions
+ spin_lock(&tlb_hook_lock);
+
+ if(hook->last)
+ {
+ hook->last->next = hook->next;
+ } else {
+ tlb_hook_root = hook->next;
+ }
+
+ if(hook->next)
+ {
+ hook->next->last = hook->last;
+ }
+
+ spin_unlock(&tlb_hook_lock);
+
+ // wait until hook is unused
+ while(hook->used)
+ {
+ cpu_relax();
+ }
+
+ return 0;
+}
+
+
+EXPORT_SYMBOL(register_tlb_hook);
+EXPORT_SYMBOL(unregister_tlb_hook);
[-- Attachment #3: tlbhook_i386.patch --]
[-- Type: text/x-diff, Size: 9489 bytes --]
diff -urP linux-2.5.59/arch/i386/kernel/smp.c linux-2.5.59_patched/arch/i386/kernel/smp.c
--- linux-2.5.59/arch/i386/kernel/smp.c Fri Jan 17 03:21:38 2003
+++ linux-2.5.59_patched/arch/i386/kernel/smp.c Sun Jan 26 21:02:22 2003
@@ -327,7 +327,7 @@
if (flush_va == FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(flush_va);
+ local_flush_tlb_one(flush_va);
} else
leave_mm(cpu);
}
@@ -382,7 +382,7 @@
spin_unlock(&tlbstate_lock);
}
-void flush_tlb_current_task(void)
+void smp_flush_tlb(void)
{
struct mm_struct *mm = current->mm;
unsigned long cpu_mask;
@@ -396,7 +396,7 @@
preempt_enable();
}
-void flush_tlb_mm (struct mm_struct * mm)
+void smp_flush_tlb_mm(struct mm_struct * mm)
{
unsigned long cpu_mask;
@@ -415,7 +415,7 @@
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
+void smp_flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long cpu_mask;
@@ -425,7 +425,7 @@
if (current->active_mm == mm) {
if(current->mm)
- __flush_tlb_one(va);
+ local_flush_tlb_one(va);
else
leave_mm(smp_processor_id());
}
@@ -440,7 +440,7 @@
{
unsigned long cpu = smp_processor_id();
- __flush_tlb_all();
+ local_flush_tlb_all();
if (cpu_tlbstate[cpu].state == TLBSTATE_LAZY)
leave_mm(cpu);
}
@@ -450,7 +450,7 @@
do_flush_tlb_all_local();
}
-void flush_tlb_all(void)
+void smp_flush_tlb_all(void)
{
smp_call_function (flush_tlb_all_ipi,0,1,1);
diff -urP linux-2.5.59/arch/i386/mach-voyager/voyager_smp.c linux-2.5.59_patched/arch/i386/mach-voyager/voyager_smp.c
--- linux-2.5.59/arch/i386/mach-voyager/voyager_smp.c Fri Jan 17 03:22:02 2003
+++ linux-2.5.59_patched/arch/i386/mach-voyager/voyager_smp.c Sun Jan 26 21:02:22 2003
@@ -892,7 +892,7 @@
if (flush_va == FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(flush_va);
+ local_flush_tlb_one(flush_va);
} else
leave_mm(cpu);
}
@@ -948,7 +948,7 @@
}
void
-flush_tlb_current_task(void)
+smp_flush_tlb(void)
{
struct mm_struct *mm = current->mm;
unsigned long cpu_mask;
@@ -965,7 +965,7 @@
void
-flush_tlb_mm (struct mm_struct * mm)
+smp_flush_tlb_mm(struct mm_struct * mm)
{
unsigned long cpu_mask;
@@ -985,7 +985,7 @@
preempt_enable();
}
-void flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
+void smp_flush_tlb_page(struct vm_area_struct * vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long cpu_mask;
@@ -995,7 +995,7 @@
cpu_mask = mm->cpu_vm_mask & ~(1 << smp_processor_id());
if (current->active_mm == mm) {
if(current->mm)
- __flush_tlb_one(va);
+ local_flush_tlb_one(va);
else
leave_mm(smp_processor_id());
}
@@ -1217,7 +1217,7 @@
{
unsigned long cpu = smp_processor_id();
- __flush_tlb_all();
+ local_flush_tlb_all();
if (cpu_tlbstate[cpu].state == TLBSTATE_LAZY)
leave_mm(cpu);
}
@@ -1231,7 +1231,7 @@
/* flush the TLB of every active CPU in the system */
void
-flush_tlb_all(void)
+smp_flush_tlb_all(void)
{
smp_call_function (flush_tlb_all_function, 0, 1, 1);
diff -urP linux-2.5.59/arch/i386/mm/highmem.c linux-2.5.59_patched/arch/i386/mm/highmem.c
--- linux-2.5.59/arch/i386/mm/highmem.c Fri Jan 17 03:22:14 2003
+++ linux-2.5.59_patched/arch/i386/mm/highmem.c Sun Jan 26 21:02:22 2003
@@ -42,7 +42,7 @@
BUG();
#endif
set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
return (void*) vaddr;
}
@@ -66,7 +66,7 @@
* this pte without first remap it
*/
pte_clear(kmap_pte-idx);
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
#endif
dec_preempt_count();
diff -urP linux-2.5.59/arch/i386/mm/init.c linux-2.5.59_patched/arch/i386/mm/init.c
--- linux-2.5.59/arch/i386/mm/init.c Fri Jan 17 03:22:27 2003
+++ linux-2.5.59_patched/arch/i386/mm/init.c Sun Jan 26 21:02:22 2003
@@ -369,7 +369,7 @@
if (cpu_has_pae)
set_in_cr4(X86_CR4_PAE);
#endif
- __flush_tlb_all();
+ local_flush_tlb_all();
kmap_init();
zone_sizes_init();
diff -urP linux-2.5.59/arch/i386/mm/pageattr.c linux-2.5.59_patched/arch/i386/mm/pageattr.c
--- linux-2.5.59/arch/i386/mm/pageattr.c Fri Jan 17 03:22:04 2003
+++ linux-2.5.59_patched/arch/i386/mm/pageattr.c Sun Jan 26 21:02:22 2003
@@ -53,7 +53,7 @@
/* Flush all to work around Errata in early athlons regarding
* large page flushing.
*/
- __flush_tlb_all();
+ local_flush_tlb_all();
}
static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
diff -urP linux-2.5.59/arch/i386/mm/pgtable.c linux-2.5.59_patched/arch/i386/mm/pgtable.c
--- linux-2.5.59/arch/i386/mm/pgtable.c Fri Jan 17 03:23:01 2003
+++ linux-2.5.59_patched/arch/i386/mm/pgtable.c Sun Jan 26 21:02:22 2003
@@ -81,7 +81,7 @@
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
}
/*
@@ -114,7 +114,7 @@
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one(vaddr);
+ local_flush_tlb_one(vaddr);
}
void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
diff -urP linux-2.5.59/include/asm-i386/tlbflush.h linux-2.5.59_patched/include/asm-i386/tlbflush.h
--- linux-2.5.59/include/asm-i386/tlbflush.h Fri Jan 17 03:22:49 2003
+++ linux-2.5.59_patched/include/asm-i386/tlbflush.h Sun Jan 26 21:02:22 2003
@@ -2,10 +2,10 @@
#define _I386_TLBFLUSH_H
#include <linux/config.h>
-#include <linux/mm.h>
+#include <linux/tlbhook.h>
#include <asm/processor.h>
-#define __flush_tlb() \
+#define local_flush_tlb() \
do { \
unsigned int tmpreg; \
\
@@ -37,12 +37,12 @@
extern unsigned long pgkern_mask;
-# define __flush_tlb_all() \
+# define local_flush_tlb_all() \
do { \
if (cpu_has_pge) \
__flush_tlb_global(); \
else \
- __flush_tlb(); \
+ local_flush_tlb(); \
} while (0)
#define cpu_has_invlpg (boot_cpu_data.x86 > 3)
@@ -51,14 +51,14 @@
__asm__ __volatile__("invlpg %0": :"m" (*(char *) addr))
#ifdef CONFIG_X86_INVLPG
-# define __flush_tlb_one(addr) __flush_tlb_single(addr)
+# define local_flush_tlb_one(addr) __flush_tlb_single(addr)
#else
-# define __flush_tlb_one(addr) \
+# define local_flush_tlb_one(addr) \
do { \
if (cpu_has_invlpg) \
__flush_tlb_single(addr); \
else \
- __flush_tlb(); \
+ local_flush_tlb(); \
} while (0)
#endif
@@ -79,47 +79,94 @@
#ifndef CONFIG_SMP
-#define flush_tlb() __flush_tlb()
-#define flush_tlb_all() __flush_tlb_all()
-#define local_flush_tlb() __flush_tlb()
+static inline void flush_tlb(void)
+{
+ flush_tlb_hook();
+ local_flush_tlb();
+}
+
+static inline void flush_tlb_all(void)
+{
+ flush_tlb_all_hook();
+ local_flush_tlb_all();
+}
static inline void flush_tlb_mm(struct mm_struct *mm)
{
+ flush_tlb_mm_hook(mm);
if (mm == current->active_mm)
- __flush_tlb();
+ local_flush_tlb();
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
+ flush_tlb_page_hook(vma, addr);
if (vma->vm_mm == current->active_mm)
- __flush_tlb_one(addr);
+ local_flush_tlb_one(addr);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
+ flush_tlb_range_hook(vma, start, end);
if (vma->vm_mm == current->active_mm)
- __flush_tlb();
+ local_flush_tlb();
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+ unsigned long end)
+{
+ flush_tlb_kernel_range_hook(start, end);
+ local_flush_tlb_all();
}
#else
#include <asm/smp.h>
-#define local_flush_tlb() \
- __flush_tlb()
+extern void smp_flush_tlb(void);
+extern void smp_flush_tlb_all(void);
+extern void smp_flush_tlb_mm(struct mm_struct *);
+extern void smp_flush_tlb_page(struct vm_area_struct *, unsigned long);
+
+static inline void flush_tlb(void)
+{
+ flush_tlb_hook();
+ smp_flush_tlb();
+}
+
+static inline void flush_tlb_all(void)
+{
+ flush_tlb_all_hook();
+ smp_flush_tlb_all();
+}
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+ flush_tlb_mm_hook(mm);
+ smp_flush_tlb_mm(mm);
+}
-extern void flush_tlb_all(void);
-extern void flush_tlb_current_task(void);
-extern void flush_tlb_mm(struct mm_struct *);
-extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ flush_tlb_page_hook(vma, addr);
+ smp_flush_tlb_page(vma, addr);
+}
-#define flush_tlb() flush_tlb_current_task()
+static inline void flush_tlb_range(struct vm_area_struct * vma,
+ unsigned long start, unsigned long end)
+{
+ flush_tlb_range_hook(vma, start, end);
+ smp_flush_tlb_mm(vma->vm_mm);
+}
-static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long start, unsigned long end)
+static inline void flush_tlb_kernel_range(unsigned long start,
+ unsigned long end)
{
- flush_tlb_mm(vma->vm_mm);
+ flush_tlb_kernel_range_hook(start, end);
+ smp_flush_tlb_all();
}
#define TLBSTATE_OK 1
@@ -136,11 +183,10 @@
#endif
-#define flush_tlb_kernel_range(start, end) flush_tlb_all()
-
static inline void flush_tlb_pgtables(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
+ flush_tlb_pgtables_hook(mm, start, end);
/* i386 does not keep any page table caches in TLB */
}
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2003-01-26 23:21 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-01-24 14:24 [PATCH] to support hookable flush_tlb* functions Thomas Schlichter
2003-01-24 21:21 ` Andrew Morton
2003-01-24 22:39 ` David S. Miller
2003-01-26 23:30 ` Thomas Schlichter
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