Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-12 Thread Frederic Weisbecker
Le Thu, Jun 12, 2025 at 11:06:07AM +0800, Xiongfeng Wang a écrit : > +cc (Qi, my colleague who helps testing the modification) > > On 2025/6/10 20:23, Frederic Weisbecker wrote: > > Le Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes a écrit : > >> During rcu_read_unlock_special(), if this ha

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-11 Thread Xiongfeng Wang
+cc (Qi, my colleague who helps testing the modification) On 2025/6/10 20:23, Frederic Weisbecker wrote: > Le Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes a écrit : >> During rcu_read_unlock_special(), if this happens during irq_exit(), we ...skipped... We have tested the below modifica

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-11 Thread Boqun Feng
On Wed, Jun 11, 2025 at 09:16:05AM -0700, Paul E. McKenney wrote: > On Wed, Jun 11, 2025 at 09:05:06AM -0700, Boqun Feng wrote: > > On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > > > During rcu_read_unlock_special(), if this happens during irq_exit(), we > > > can lockup if an IP

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-11 Thread Boqun Feng
On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > During rcu_read_unlock_special(), if this happens during irq_exit(), we > can lockup if an IPI is issued. This is because the IPI itself triggers > the irq_exit() path causing a recursive lock up. > > This is precisely what Xiongfen

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-11 Thread Paul E. McKenney
On Wed, Jun 11, 2025 at 09:05:06AM -0700, Boqun Feng wrote: > On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > > During rcu_read_unlock_special(), if this happens during irq_exit(), we > > can lockup if an IPI is issued. This is because the IPI itself triggers > > the irq_exit() pa

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-10 Thread Joel Fernandes
On 6/10/2025 8:23 AM, Frederic Weisbecker wrote: > Le Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes a écrit : >> During rcu_read_unlock_special(), if this happens during irq_exit(), we >> can lockup if an IPI is issued. This is because the IPI itself triggers >> the irq_exit() path causi

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-10 Thread Frederic Weisbecker
Le Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes a écrit : > During rcu_read_unlock_special(), if this happens during irq_exit(), we > can lockup if an IPI is issued. This is because the IPI itself triggers > the irq_exit() path causing a recursive lock up. > > This is precisely what Xiong

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-09 Thread Boqun Feng
On Tue, Jun 10, 2025 at 01:26:46AM +0200, Frederic Weisbecker wrote: > Le Mon, Jun 09, 2025 at 12:49:06PM -0700, Boqun Feng a écrit : > > Hi Joel, > > > > On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > > > During rcu_read_unlock_special(), if this happens during irq_exit(), we >

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-09 Thread Frederic Weisbecker
Le Mon, Jun 09, 2025 at 12:49:06PM -0700, Boqun Feng a écrit : > Hi Joel, > > On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > > During rcu_read_unlock_special(), if this happens during irq_exit(), we > > can lockup if an IPI is issued. This is because the IPI itself triggers > >

Re: [PATCH 2/2] rcu: Fix lockup when RCU reader used while IRQ exiting

2025-06-09 Thread Boqun Feng
Hi Joel, On Mon, Jun 09, 2025 at 02:01:24PM -0400, Joel Fernandes wrote: > During rcu_read_unlock_special(), if this happens during irq_exit(), we > can lockup if an IPI is issued. This is because the IPI itself triggers > the irq_exit() path causing a recursive lock up. > > This is precisely wha