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authorJens Axboe <axboe@kernel.dk>2024-05-11 08:25:55 -0600
committerJens Axboe <axboe@kernel.dk>2024-05-11 08:25:55 -0600
commitfe6532b44af402d0900c5be3e5359f4b293524b1 (patch)
tree6cd3f9e365f14126b69979b85df2cf458f4bb23b /lib/dynamic_queue_limits.c
parentad1978dbbd827c1a1a7d22d9cc9ba71989dae48a (diff)
parentcddd2dc6390b90e62cec2768424d1d90f6d04161 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next into net-accept-more
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1557 commits) net: qede: use extack in qede_parse_actions() net: qede: propagate extack through qede_flow_spec_validate() net: qede: use faked extack in qede_flow_spec_to_rule() net: qede: use extack in qede_parse_flow_attr() net: qede: add extack in qede_add_tc_flower_fltr() net: qede: use extack in qede_flow_parse_udp_v4() net: qede: use extack in qede_flow_parse_udp_v6() net: qede: use extack in qede_flow_parse_tcp_v4() net: qede: use extack in qede_flow_parse_tcp_v6() net: qede: use extack in qede_flow_parse_v4_common() net: qede: use extack in qede_flow_parse_v6_common() net: qede: use extack in qede_set_v4_tuple_to_profile() net: qede: use extack in qede_set_v6_tuple_to_profile() net: qede: use extack in qede_flow_parse_ports() net: usb: smsc95xx: stop lying about skb->truesize net: dsa: microchip: Fix spellig mistake "configur" -> "configure" af_unix: Add dead flag to struct scm_fp_list. net: ethernet: adi: adin1110: Replace linux/gpio.h by proper one octeontx2-pf: Reuse Transmit queue/Send queue index of HTB class gve: Use ethtool_sprintf/puts() to fill stats strings ...
Diffstat (limited to 'lib/dynamic_queue_limits.c')
-rw-r--r--lib/dynamic_queue_limits.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
index a1389db1c30a..e49deddd3de9 100644
--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -15,12 +15,10 @@
#define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0)
#define AFTER_EQ(A, B) ((int)((A) - (B)) >= 0)
-static void dql_check_stall(struct dql *dql)
+static void dql_check_stall(struct dql *dql, unsigned short stall_thrs)
{
- unsigned short stall_thrs;
unsigned long now;
- stall_thrs = READ_ONCE(dql->stall_thrs);
if (!stall_thrs)
return;
@@ -86,9 +84,16 @@ void dql_completed(struct dql *dql, unsigned int count)
{
unsigned int inprogress, prev_inprogress, limit;
unsigned int ovlimit, completed, num_queued;
+ unsigned short stall_thrs;
bool all_prev_completed;
num_queued = READ_ONCE(dql->num_queued);
+ /* Read stall_thrs in advance since it belongs to the same (first)
+ * cache line as ->num_queued. This way, dql_check_stall() does not
+ * need to touch the first cache line again later, reducing the window
+ * of possible false sharing.
+ */
+ stall_thrs = READ_ONCE(dql->stall_thrs);
/* Can't complete more than what's in queue */
BUG_ON(count > num_queued - dql->num_completed);
@@ -178,7 +183,7 @@ void dql_completed(struct dql *dql, unsigned int count)
dql->num_completed = completed;
dql->prev_num_queued = num_queued;
- dql_check_stall(dql);
+ dql_check_stall(dql, stall_thrs);
}
EXPORT_SYMBOL(dql_completed);