[lustre-devel] [PATCH 23/32] lustre: ptlrpc: make ptlrpc_last_xid an atomic64_t
NeilBrown
neilb at suse.com
Wed Mar 13 17:11:51 PDT 2019
This variable is treated like ant atomic64_t,
so change it's type and simplify the code.
Signed-off-by: NeilBrown <neilb at suse.com>
---
drivers/staging/lustre/lustre/ptlrpc/client.c | 39 ++++++-------------------
1 file changed, 10 insertions(+), 29 deletions(-)
diff --git a/drivers/staging/lustre/lustre/ptlrpc/client.c b/drivers/staging/lustre/lustre/ptlrpc/client.c
index 2514a142e799..ddf44c854200 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/client.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/client.c
@@ -2999,8 +2999,7 @@ void ptlrpc_abort_set(struct ptlrpc_request_set *set)
}
}
-static u64 ptlrpc_last_xid;
-static spinlock_t ptlrpc_last_xid_lock;
+static atomic64_t ptlrpc_last_xid;
/**
* Initialize the XID for the node. This is common among all requests on
@@ -3021,19 +3020,20 @@ static spinlock_t ptlrpc_last_xid_lock;
void ptlrpc_init_xid(void)
{
time64_t now = ktime_get_real_seconds();
+ u64 xid;
- spin_lock_init(&ptlrpc_last_xid_lock);
if (now < YEAR_2004) {
- get_random_bytes(&ptlrpc_last_xid, sizeof(ptlrpc_last_xid));
- ptlrpc_last_xid >>= 2;
- ptlrpc_last_xid |= (1ULL << 61);
+ get_random_bytes(&xid, sizeof(xid));
+ xid >>= 2;
+ xid |= (1ULL << 61);
} else {
- ptlrpc_last_xid = (u64)now << 20;
+ xid = (u64)now << 20;
}
/* Always need to be aligned to a power-of-two for multi-bulk BRW */
BUILD_BUG_ON(((PTLRPC_BULK_OPS_COUNT - 1) & PTLRPC_BULK_OPS_COUNT) != 0);
- ptlrpc_last_xid &= PTLRPC_BULK_OPS_MASK;
+ xid &= PTLRPC_BULK_OPS_MASK;
+ atomic64_set(&ptlrpc_last_xid, xid);
}
/**
@@ -3050,14 +3050,7 @@ void ptlrpc_init_xid(void)
*/
u64 ptlrpc_next_xid(void)
{
- u64 next;
-
- spin_lock(&ptlrpc_last_xid_lock);
- next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
- ptlrpc_last_xid = next;
- spin_unlock(&ptlrpc_last_xid_lock);
-
- return next;
+ return atomic64_add_return(PTLRPC_BULK_OPS_COUNT, &ptlrpc_last_xid);
}
/**
@@ -3131,19 +3124,7 @@ void ptlrpc_set_bulk_mbits(struct ptlrpc_request *req)
*/
u64 ptlrpc_sample_next_xid(void)
{
-#if BITS_PER_LONG == 32
- /* need to avoid possible word tearing on 32-bit systems */
- u64 next;
-
- spin_lock(&ptlrpc_last_xid_lock);
- next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
- spin_unlock(&ptlrpc_last_xid_lock);
-
- return next;
-#else
- /* No need to lock, since returned value is racy anyways */
- return ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
-#endif
+ return atomic64_read(&ptlrpc_last_xid) + PTLRPC_BULK_OPS_COUNT;
}
EXPORT_SYMBOL(ptlrpc_sample_next_xid);
More information about the lustre-devel
mailing list