[PATCH 09/12] task_isolation: net: don't flush backlog on CPUs running isolated tasks
From: Alex Belits <hidden>
Date: 2020-03-04 16:14:00
Also in:
linux-arch, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Yuri Norov <redacted> If CPU runs isolated task, there's no any backlog on it, and so we don't need to flush it. Currently flush_all_backlogs() enqueues corresponding work on all CPUs including ones that run isolated tasks. It leads to breaking task isolation for nothing. In this patch, backlog flushing is enqueued only on non-isolated CPUs. Signed-off-by: Alex Belits <redacted> --- net/core/dev.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index c6c985fe7b1b..6d32abb1f06d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -74,6 +74,7 @@ #include <linux/cpu.h> #include <linux/types.h> #include <linux/kernel.h> +#include <linux/isolation.h> #include <linux/hash.h> #include <linux/slab.h> #include <linux/sched.h>
@@ -5518,9 +5519,12 @@ static void flush_all_backlogs(void) get_online_cpus(); - for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + if (task_isolation_on_cpu(cpu)) + continue; queue_work_on(cpu, system_highpri_wq, per_cpu_ptr(&flush_works, cpu)); + } for_each_online_cpu(cpu) flush_work(per_cpu_ptr(&flush_works, cpu));
--
2.20.1