hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

net: sched: Allow statistics reads from softirq. 

Eric reported that the rate estimator reads statics from the softirq
which in turn triggers a warning introduced in the statistics rework.

The warning is too cautious. The updates happen in the softirq context
so reads from softirq are fine since the writes can not be preempted.
The updates/writes happen during qdisc_run() which ensures one writer
and the softirq context.
The remaining bad context for reading statistics remains in hard-IRQ
because it may preempt a writer.

Fixes: 29cbcd8582 ("net: sched: Remove Qdisc::running sequence counter")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sebastian Andrzej Siewior 2021-10-19 12:12:04 +02:00 committed by David S. Miller
parent dc90604b58
commit e22db7bd55
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/core/gen_stats.c
View File

@ -154,7 +154,7 @@ void gnet_stats_add_basic(struct gnet_stats_basic_sync *bstats,
u64 bytes = 0;
u64 packets = 0;
WARN_ON_ONCE((cpu || running) && !in_task());
WARN_ON_ONCE((cpu || running) && in_hardirq());
if (cpu) {
gnet_stats_add_basic_cpu(bstats, cpu);