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提交 c8c08ec4 创建 作者: Nickolai Zeldovich's avatar Nickolai Zeldovich
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more use of atomic<>

上级 96f1dc3a
隐藏空白字符变更
内嵌 并排
正在显示 包含 34 行增加 和 21 行删除
atomic_2.h
浏览文件 @ c8c08ec4
...@@ -642,6 +642,22 @@ namespace __atomic2 ...@@ -642,6 +642,22 @@ namespace __atomic2
return __p1o == __p1n; return __p1o == __p1n;
} }
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst)
{
return compare_exchange_strong(__p1, __p2, __m,
__calculate_memory_order(__m));
}
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst) volatile
{
return compare_exchange_strong(__p1, __p2, __m,
__calculate_memory_order(__m));
}
__pointer_type __pointer_type
fetch_add(ptrdiff_t __d, memory_order __m = memory_order_seq_cst) fetch_add(ptrdiff_t __d, memory_order __m = memory_order_seq_cst)
{ return __sync_fetch_and_add(&_M_p, __d); } { return __sync_fetch_and_add(&_M_p, __d); }
......
fs.cc
浏览文件 @ c8c08ec4
...@@ -146,7 +146,7 @@ ino_hash(const pair<u32, u32> &p) ...@@ -146,7 +146,7 @@ ino_hash(const pair<u32, u32> &p)
static xns<pair<u32, u32>, inode*, ino_hash> *ins; static xns<pair<u32, u32>, inode*, ino_hash> *ins;
static struct { u32 x __mpalign__; } icache_free[NCPU]; static struct { atomic<u32> x __mpalign__; } icache_free[NCPU];
void void
initinode(void) initinode(void)
...@@ -299,7 +299,7 @@ iget(u32 dev, u32 inum) ...@@ -299,7 +299,7 @@ iget(u32 dev, u32 inum)
ins->remove(mkpair(victim->dev, victim->inum), &victim); ins->remove(mkpair(victim->dev, victim->inum), &victim);
gc_delayed(victim); gc_delayed(victim);
} else { } else {
if (!__sync_bool_compare_and_swap(&icache_free[mycpu()->id].x, cur_free, cur_free-1)) if (!icache_free[mycpu()->id].x.compare_exchange_strong(cur_free, cur_free-1))
goto retry_evict; goto retry_evict;
} }
...@@ -420,7 +420,7 @@ iput(struct inode *ip) ...@@ -420,7 +420,7 @@ iput(struct inode *ip)
ins->remove(mkpair(ip->dev, ip->inum), &ip); ins->remove(mkpair(ip->dev, ip->inum), &ip);
gc_delayed(ip); gc_delayed(ip);
__sync_fetch_and_add(&icache_free[mycpu()->id].x, 1); icache_free[mycpu()->id].x++;
return; return;
} }
release(&ip->lock); release(&ip->lock);
......
gc.cc
浏览文件 @ c8c08ec4
...@@ -35,8 +35,8 @@ enum { gc_debug = 0 }; ...@@ -35,8 +35,8 @@ enum { gc_debug = 0 };
#define NGC 10000 #define NGC 10000
struct headinfo { struct headinfo {
rcu_freed *head; atomic<rcu_freed*> head;
u64 epoch; atomic<u64> epoch;
}; };
static struct gc_state { static struct gc_state {
...@@ -51,10 +51,10 @@ static struct gc_state { ...@@ -51,10 +51,10 @@ static struct gc_state {
} __mpalign__ gc_state[NCPU] __mpalign__; } __mpalign__ gc_state[NCPU] __mpalign__;
static struct { struct spinlock l __mpalign__; } gc_lock; static struct { struct spinlock l __mpalign__; } gc_lock;
u64 global_epoch __mpalign__; atomic<u64> global_epoch __mpalign__;
static int static int
gc_free_tofreelist(rcu_freed **head, u64 epoch) gc_free_tofreelist(atomic<rcu_freed*> *head, u64 epoch)
{ {
int nfree = 0; int nfree = 0;
rcu_freed *r, *nr; rcu_freed *r, *nr;
...@@ -79,21 +79,19 @@ gc_move_to_tofree_cpu(int c, u64 epoch) ...@@ -79,21 +79,19 @@ gc_move_to_tofree_cpu(int c, u64 epoch)
{ {
rcu_freed *head; rcu_freed *head;
u32 fe = (epoch - (NEPOCH-2)) % NEPOCH; u32 fe = (epoch - (NEPOCH-2)) % NEPOCH;
int cas;
assert(gc_state[c].delayed[fe].epoch == epoch-(NEPOCH-2)); // XXX race with setting epoch = 0 assert(gc_state[c].delayed[fe].epoch == epoch-(NEPOCH-2)); // XXX race with setting epoch = 0
// unhook list for fe epoch atomically; this shouldn't fail // unhook list for fe epoch atomically; this shouldn't fail
head = gc_state[c].delayed[fe].head; head = gc_state[c].delayed[fe].head;
cas = __sync_bool_compare_and_swap(&(gc_state[c].delayed[fe].head), head, 0); while (!gc_state[c].delayed[fe].head.compare_exchange_strong(head, (rcu_freed*)0)) {}
assert(cas);
// insert list into tofree list so that each core can free in parallel and free its elements // insert list into tofree list so that each core can free in parallel and free its elements
if(gc_state[c].tofree[fe].epoch != gc_state[c].delayed[fe].epoch) { if(gc_state[c].tofree[fe].epoch != gc_state[c].delayed[fe].epoch) {
cprintf("%d: tofree epoch %lu delayed epoch %lu\n", c, gc_state[c].tofree[fe].epoch, cprintf("%d: tofree epoch %lu delayed epoch %lu\n", c,
gc_state[c].delayed[fe].epoch); gc_state[c].tofree[fe].epoch.load(),
gc_state[c].delayed[fe].epoch.load());
assert(0); assert(0);
} }
cas = __sync_bool_compare_and_swap(&(gc_state[c].tofree[fe].head), 0, head); assert(gc_state[c].tofree[fe].head.exchange(head) == 0);
assert(cas);
// move delayed NEPOCH's adhead // move delayed NEPOCH's adhead
gc_state[c].delayed[fe].epoch += NEPOCH; gc_state[c].delayed[fe].epoch += NEPOCH;
...@@ -111,8 +109,7 @@ gc_move_to_tofree(u64 epoch) ...@@ -111,8 +109,7 @@ gc_move_to_tofree(u64 epoch)
for (int c = 0; c < ncpu; c++) { for (int c = 0; c < ncpu; c++) {
gc_move_to_tofree_cpu(c, epoch); gc_move_to_tofree_cpu(c, epoch);
} }
int ok = __sync_bool_compare_and_swap(&global_epoch, epoch, epoch+1); assert(global_epoch.compare_exchange_strong(epoch, epoch+1));
assert(ok);
} }
// If all threads have seen global_epoch, we can move elements in global_epoch-2 to tofreelist // If all threads have seen global_epoch, we can move elements in global_epoch-2 to tofreelist
...@@ -164,15 +161,15 @@ gc_delayed(rcu_freed *e) ...@@ -164,15 +161,15 @@ gc_delayed(rcu_freed *e)
u64 myepoch = myproc()->epoch; u64 myepoch = myproc()->epoch;
u64 minepoch = gc_state[c].delayed[myepoch % NEPOCH].epoch; u64 minepoch = gc_state[c].delayed[myepoch % NEPOCH].epoch;
if (gc_debug) if (gc_debug)
cprintf("(%d, %d): gc_delayed: %lu ndelayed %d\n", c, myproc()->pid, global_epoch, gc_state[c].ndelayed.load()); cprintf("(%d, %d): gc_delayed: %lu ndelayed %d\n", c, myproc()->pid,
global_epoch.load(), gc_state[c].ndelayed.load());
if (myepoch != minepoch) { if (myepoch != minepoch) {
cprintf("%d: myepoch %lu minepoch %lu\n", myproc()->pid, myepoch, minepoch); cprintf("%d: myepoch %lu minepoch %lu\n", myproc()->pid, myepoch, minepoch);
panic("gc_delayed_int"); panic("gc_delayed_int");
} }
e->_rcu_epoch = myepoch; e->_rcu_epoch = myepoch;
do { e->_rcu_next = gc_state[c].delayed[myepoch % NEPOCH].head;
e->_rcu_next = gc_state[c].delayed[myepoch % NEPOCH].head; while (!gc_state[c].delayed[myepoch % NEPOCH].head.compare_exchange_strong(e->_rcu_next, e)) {}
} while (!__sync_bool_compare_and_swap(&(gc_state[c].delayed[myepoch % NEPOCH].head), e->_rcu_next, e));
popcli(); popcli();
} }
...@@ -226,7 +223,7 @@ gc_worker(void *x) ...@@ -226,7 +223,7 @@ gc_worker(void *x)
u64 global = global_epoch; u64 global = global_epoch;
myproc()->epoch = global_epoch; // move the gc thread to next epoch myproc()->epoch = global_epoch; // move the gc thread to next epoch
for (i = gc_state[mycpu()->id].min_epoch; i < global-2; i++) { for (i = gc_state[mycpu()->id].min_epoch; i < global-2; i++) {
int nfree = gc_free_tofreelist(&(gc_state[mycpu()->id].tofree[i%NEPOCH].head), i); int nfree = gc_free_tofreelist(&gc_state[mycpu()->id].tofree[i%NEPOCH].head, i);
gc_state[mycpu()->id].tofree[i%NEPOCH].epoch += NEPOCH; gc_state[mycpu()->id].tofree[i%NEPOCH].epoch += NEPOCH;
gc_state[mycpu()->id].ndelayed -= nfree; gc_state[mycpu()->id].ndelayed -= nfree;
if (0 && nfree > 0) { if (0 && nfree > 0) {
......
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