diff mbox series

[net-next,12/14] net_sched: sch_hhf: implement lockless hhf_dump()

Message ID 20240415132054.3822230-13-edumazet@google.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net_sched: first series for RTNL-less qdisc dumps | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 926 this patch: 926
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 937 this patch: 937
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 937 this patch: 937
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 63 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-18--00-00 (tests: 961)

Commit Message

Eric Dumazet April 15, 2024, 1:20 p.m. UTC 
Instead of relying on RTNL, hhf_dump() can use READ_ONCE()
annotations, paired with WRITE_ONCE() ones in hhf_change().

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/sched/sch_hhf.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

Comments

Simon Horman April 17, 2024, 5:26 p.m. UTC | #1 
On Mon, Apr 15, 2024 at 01:20:52PM +0000, Eric Dumazet wrote:
> Instead of relying on RTNL, hhf_dump() can use READ_ONCE()
> annotations, paired with WRITE_ONCE() ones in hhf_change().
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Simon Horman <horms@kernel.org>
diff mbox series

Patch

diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index 3f906df1435b2edea4286ba56bab68066be238b1..44d9efe1a96a89bdb44a6d48071b3eed90fd5554 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -534,27 +534,31 @@  static int hhf_change(struct Qdisc *sch, struct nlattr *opt,
 	sch_tree_lock(sch);
 
 	if (tb[TCA_HHF_BACKLOG_LIMIT])
-		sch->limit = nla_get_u32(tb[TCA_HHF_BACKLOG_LIMIT]);
+		WRITE_ONCE(sch->limit, nla_get_u32(tb[TCA_HHF_BACKLOG_LIMIT]));
 
-	q->quantum = new_quantum;
-	q->hhf_non_hh_weight = new_hhf_non_hh_weight;
+	WRITE_ONCE(q->quantum, new_quantum);
+	WRITE_ONCE(q->hhf_non_hh_weight, new_hhf_non_hh_weight);
 
 	if (tb[TCA_HHF_HH_FLOWS_LIMIT])
-		q->hh_flows_limit = nla_get_u32(tb[TCA_HHF_HH_FLOWS_LIMIT]);
+		WRITE_ONCE(q->hh_flows_limit,
+			   nla_get_u32(tb[TCA_HHF_HH_FLOWS_LIMIT]));
 
 	if (tb[TCA_HHF_RESET_TIMEOUT]) {
 		u32 us = nla_get_u32(tb[TCA_HHF_RESET_TIMEOUT]);
 
-		q->hhf_reset_timeout = usecs_to_jiffies(us);
+		WRITE_ONCE(q->hhf_reset_timeout,
+			   usecs_to_jiffies(us));
 	}
 
 	if (tb[TCA_HHF_ADMIT_BYTES])
-		q->hhf_admit_bytes = nla_get_u32(tb[TCA_HHF_ADMIT_BYTES]);
+		WRITE_ONCE(q->hhf_admit_bytes,
+			   nla_get_u32(tb[TCA_HHF_ADMIT_BYTES]));
 
 	if (tb[TCA_HHF_EVICT_TIMEOUT]) {
 		u32 us = nla_get_u32(tb[TCA_HHF_EVICT_TIMEOUT]);
 
-		q->hhf_evict_timeout = usecs_to_jiffies(us);
+		WRITE_ONCE(q->hhf_evict_timeout,
+			   usecs_to_jiffies(us));
 	}
 
 	qlen = sch->q.qlen;
@@ -657,15 +661,18 @@  static int hhf_dump(struct Qdisc *sch, struct sk_buff *skb)
 	if (opts == NULL)
 		goto nla_put_failure;
 
-	if (nla_put_u32(skb, TCA_HHF_BACKLOG_LIMIT, sch->limit) ||
-	    nla_put_u32(skb, TCA_HHF_QUANTUM, q->quantum) ||
-	    nla_put_u32(skb, TCA_HHF_HH_FLOWS_LIMIT, q->hh_flows_limit) ||
+	if (nla_put_u32(skb, TCA_HHF_BACKLOG_LIMIT, READ_ONCE(sch->limit)) ||
+	    nla_put_u32(skb, TCA_HHF_QUANTUM, READ_ONCE(q->quantum)) ||
+	    nla_put_u32(skb, TCA_HHF_HH_FLOWS_LIMIT,
+			READ_ONCE(q->hh_flows_limit)) ||
 	    nla_put_u32(skb, TCA_HHF_RESET_TIMEOUT,
-			jiffies_to_usecs(q->hhf_reset_timeout)) ||
-	    nla_put_u32(skb, TCA_HHF_ADMIT_BYTES, q->hhf_admit_bytes) ||
+			jiffies_to_usecs(READ_ONCE(q->hhf_reset_timeout))) ||
+	    nla_put_u32(skb, TCA_HHF_ADMIT_BYTES,
+			READ_ONCE(q->hhf_admit_bytes)) ||
 	    nla_put_u32(skb, TCA_HHF_EVICT_TIMEOUT,
-			jiffies_to_usecs(q->hhf_evict_timeout)) ||
-	    nla_put_u32(skb, TCA_HHF_NON_HH_WEIGHT, q->hhf_non_hh_weight))
+			jiffies_to_usecs(READ_ONCE(q->hhf_evict_timeout))) ||
+	    nla_put_u32(skb, TCA_HHF_NON_HH_WEIGHT,
+			READ_ONCE(q->hhf_non_hh_weight)))
 		goto nla_put_failure;
 
 	return nla_nest_end(skb, opts);