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提交 b26a4051 创建 作者: Frans Kaashoek's avatar Frans Kaashoek
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per-core freelist for kmalloc/kfree

上级 d57e7faf
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正在显示 包含 32 行增加 和 19 行删除
kalloc.c
浏览文件 @ b26a4051
...@@ -13,10 +13,10 @@ ...@@ -13,10 +13,10 @@
#include "kalloc.h" #include "kalloc.h"
#include "xv6-mtrace.h" #include "xv6-mtrace.h"
struct kmem kmems[NCPU]; void kminit(void);
struct kmem kmems[NCPU];
extern char end[]; // first address after kernel loaded from ELF file extern char end[]; // first address after kernel loaded from ELF file
struct spinlock free_lock;
static void __attribute__((unused)) static void __attribute__((unused))
kmemprint(void) kmemprint(void)
...@@ -45,8 +45,7 @@ kinit(void) ...@@ -45,8 +45,7 @@ kinit(void)
p = (char*)PGROUNDUP((uint)end); p = (char*)PGROUNDUP((uint)end);
for(; p + PGSIZE <= (char*)PHYSTOP; p += PGSIZE) for(; p + PGSIZE <= (char*)PHYSTOP; p += PGSIZE)
kfree(p); kfree(p);
kminit();
initlock(&free_lock, "malloc");
} }
//PAGEBREAK: 21 //PAGEBREAK: 21
...@@ -137,8 +136,22 @@ union header { ...@@ -137,8 +136,22 @@ union header {
typedef union header Header; typedef union header Header;
static Header base; static struct freelist {
static Header *freep; // last allocated block Header base;
Header *freep; // last allocated block
struct spinlock lock;
char name[MAXNAME];
} freelists[NCPU];
void
kminit(void)
{
for (int c = 0; c < NCPU; c++) {
freelists[c].name[0] = (char) c + '0';
safestrcpy(freelists[c].name+1, "freelist", MAXNAME-1);
initlock(&freelists[c].lock, freelists[c].name);
}
}
static void static void
domfree(void *ap) domfree(void *ap)
...@@ -146,7 +159,7 @@ domfree(void *ap) ...@@ -146,7 +159,7 @@ domfree(void *ap)
Header *bp, *p; Header *bp, *p;
bp = (Header*)ap - 1; bp = (Header*)ap - 1;
for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr) for(p = freelists[cpu->id].freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr)
if(p >= p->s.ptr && (bp > p || bp < p->s.ptr)) if(p >= p->s.ptr && (bp > p || bp < p->s.ptr))
break; break;
if(bp + bp->s.size == p->s.ptr){ if(bp + bp->s.size == p->s.ptr){
...@@ -159,15 +172,15 @@ domfree(void *ap) ...@@ -159,15 +172,15 @@ domfree(void *ap)
p->s.ptr = bp->s.ptr; p->s.ptr = bp->s.ptr;
} else } else
p->s.ptr = bp; p->s.ptr = bp;
freep = p; freelists[cpu->id].freep = p;
} }
void void
kmfree(void *ap) kmfree(void *ap)
{ {
acquire(&free_lock); acquire(&freelists[cpu->id].lock);
domfree(ap); domfree(ap);
release(&free_lock); release(&freelists[cpu->id].lock);
} }
// Caller should hold free_locky // Caller should hold free_locky
...@@ -188,7 +201,7 @@ morecore(uint nu) ...@@ -188,7 +201,7 @@ morecore(uint nu)
hp = (Header*)p; hp = (Header*)p;
hp->s.size = nu; hp->s.size = nu;
domfree((void*)(hp + 1)); domfree((void*)(hp + 1));
return freep; return freelists[cpu->id].freep;
} }
void* void*
...@@ -198,11 +211,11 @@ kmalloc(uint nbytes) ...@@ -198,11 +211,11 @@ kmalloc(uint nbytes)
uint nunits; uint nunits;
void *r = 0; void *r = 0;
acquire(&free_lock); acquire(&freelists[cpu->id].lock);
nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1; nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1;
if((prevp = freep) == 0){ if((prevp = freelists[cpu->id].freep) == 0){
base.s.ptr = freep = prevp = &base; freelists[cpu->id].base.s.ptr = freelists[cpu->id].freep = prevp = &freelists[cpu->id].base;
base.s.size = 0; freelists[cpu->id].base.s.size = 0;
} }
for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){ for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){
if(p->s.size >= nunits){ if(p->s.size >= nunits){
...@@ -213,14 +226,14 @@ kmalloc(uint nbytes) ...@@ -213,14 +226,14 @@ kmalloc(uint nbytes)
p += p->s.size; p += p->s.size;
p->s.size = nunits; p->s.size = nunits;
} }
freep = prevp; freelists[cpu->id].freep = prevp;
r = (void*)(p + 1); r = (void*)(p + 1);
break; break;
} }
if(p == freep) if(p == freelists[cpu->id].freep)
if((p = morecore(nunits)) == 0) if((p = morecore(nunits)) == 0)
break; break;
} }
release(&free_lock); release(&freelists[cpu->id].lock);
return r; return r;
} }
rcu.c
浏览文件 @ b26a4051
...@@ -131,7 +131,7 @@ rcu_begin_write(struct spinlock *l) ...@@ -131,7 +131,7 @@ rcu_begin_write(struct spinlock *l)
acquire(l); acquire(l);
} }
// XXX if a process never rcu_end_write() infrequently we have a problem; run // XXX if a process never calls rcu_end_write() we have a problem; run
// rcu_gc from a kernel thread periodically? // rcu_gc from a kernel thread periodically?
void void
rcu_end_write(struct spinlock *l) rcu_end_write(struct spinlock *l)
......
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