lede/target/linux/generic/backport-5.10/604-v5.12-net-fix-hangup-on-napi_disable-for-threaded-napi.patch
Beginner e35805c6ea
kernel: bump 5.10 to 5.10.56 (#7635)
* kernel: bump 5.10 to 5.10.52

Add the new CONFIG_BATTERY_RT5033 to the generic configuration, as reported by
Paul Blazejowski. Resort the kconfig while at it.

No deleted or manually refreshed patches.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel/generic: add a missing symbol to the 5.10 kconfig

Add CONFIG_HAVE_ARM_ARCH_TIMER (disabled). A make kernel_oldconfig on cortexa9
will otherwise prompt for its selection. The 5.4 configuration already contains
the same symbol.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel/generic: sort the 5.10 kconfig symbols

Sort the kernel configuration using scripts/kconfig.pl.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel: bump 5.10 to 5.10.53

No deleted or manually refreshed patches.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel: bump 5.10 to 5.10.54

Deleted (upstreamed) patches:
mediatek/patches-5.10/000-spi-fix-fifo.patch

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel: bump 5.10 to 5.10.55

No deleted or manually refreshed patches.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

* kernel: bump 5.10 to 5.10.56

No patches needed refreshing

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>

Co-authored-by: Rui Salvaterra <rsalvaterra@gmail.com>
2021-08-10 14:18:30 +08:00

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2.0 KiB
Diff

From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 9 Apr 2021 17:24:17 +0200
Subject: [PATCH] net: fix hangup on napi_disable for threaded napi
napi_disable() is subject to an hangup, when the threaded
mode is enabled and the napi is under heavy traffic.
If the relevant napi has been scheduled and the napi_disable()
kicks in before the next napi_threaded_wait() completes - so
that the latter quits due to the napi_disable_pending() condition,
the existing code leaves the NAPI_STATE_SCHED bit set and the
napi_disable() loop waiting for such bit will hang.
This patch addresses the issue by dropping the NAPI_STATE_DISABLE
bit test in napi_thread_wait(). The later napi_threaded_poll()
iteration will take care of clearing the NAPI_STATE_SCHED.
This also addresses a related problem reported by Jakub:
before this patch a napi_disable()/napi_enable() pair killed
the napi thread, effectively disabling the threaded mode.
On the patched kernel napi_disable() simply stops scheduling
the relevant thread.
v1 -> v2:
- let the main napi_thread_poll() loop clear the SCHED bit
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: 29863d41bb6e ("net: implement threaded-able napi poll loop support")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/883923fa22745a9589e8610962b7dc59df09fb1f.1617981844.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6991,7 +6991,7 @@ static int napi_thread_wait(struct napi_
set_current_state(TASK_INTERRUPTIBLE);
- while (!kthread_should_stop() && !napi_disable_pending(napi)) {
+ while (!kthread_should_stop()) {
/* Testing SCHED_THREADED bit here to make sure the current
* kthread owns this napi and could poll on this napi.
* Testing SCHED bit is not enough because SCHED bit might be
@@ -7009,6 +7009,7 @@ static int napi_thread_wait(struct napi_
set_current_state(TASK_INTERRUPTIBLE);
}
__set_current_state(TASK_RUNNING);
+
return -1;
}