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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?u6S4Q8fCGcKU3cEin2sl1hdu8i/n8cu2CwsnawcaNOKy/XeYn+uv7H3ocyra?= =?us-ascii?Q?PZYtF4c9ALgwfojZeQA4mJoM52ajPyLegpHbg3YIgBtKOdhlfj9P50GCqjDU?= =?us-ascii?Q?UsILWRTqm5lYLKCZRku3P0b1Gf9xLXNp39ZWB9v29X+hMcjhdXeL3XfotuuA?= =?us-ascii?Q?88u+dNwIJm7tXNHiVTi27gMzN1lM15N69dLRbrAACeihRFE8MUNSt3x3OIwv?= =?us-ascii?Q?3mAYGgn9o/mQxxU1iUnZihLxd0nPtLTjTjyU+H4IvqtPdn0RzI1esc7duC+U?= =?us-ascii?Q?BjnAJCnktCnuBcWzAUlem6VA20/BYYzCM97xb1zjSZv5kGEpLk41hXrEFwNq?= =?us-ascii?Q?NU7IjOJ3iMuB//0/5eV+sjbG915U5C8GWt38l4yPvM0w4eZqHscVMRtFUX7f?= =?us-ascii?Q?Z87YpAqKL55+qcRXhwSjUXbVIRLzgTPGbhJCsuG4SD7co8qL7k+36lkUVFx7?= =?us-ascii?Q?9Ca6nAfDDX+IZqbK82kaP1uaG6jpPVkPUjlX2tGQb942S6qMd9GYHQNwcfjc?= =?us-ascii?Q?W7UNiDHcAGUaKithcAb3gGd//ePlmWks+RSgl6MkEtb2Yhlfp4NYOH0gWjQM?= =?us-ascii?Q?90v0hoJbVrLVz5FmmuAR5EG//ImT2muM474hZiVxz8bO8kqQF6P6dWiGak6V?= =?us-ascii?Q?8eYyYPF/+rkUADjTi6aVqYmYZXl/Rm2y2+rXH1YXQoR8/4etymBQh/GzGlso?= =?us-ascii?Q?M/xeWiJ9Tsm5GQL6uV3ZeqHx5gWasHuMJ1htPzkWBYLIY1EpfKUQOp5Do7gW?= =?us-ascii?Q?2S0qtxz1l7H8gLsGeEzMsiZyaYT1HhQJg5dgDdKd9aEFDfHeoaPJ3plrPH6h?= =?us-ascii?Q?R9Lmd6RZ9tpP1LHis9SfS5pJWKCnuOSGOR0zZn50YBTRTOIM/QMg8wf1mRBb?= =?us-ascii?Q?WTA5mNTFtQsej/9NRNEmWnVfNZgyQZ75wffdFBMuBydJ/HIZCl2I1Xx+1jv3?= =?us-ascii?Q?jbhhQB0o3YskwFPZe1FVfAHV+2rzC6iGJZohcq0PI6wl6OpKbBIKB2L1aM5Z?= =?us-ascii?Q?AHecjV/q2dux/qY8TTS2N98fHUoGC9ISWvvUrh1r7K/nrqCG9AcKFMSRQPbo?= =?us-ascii?Q?Yd2XHEhJNm8nxSj9+Xhl0au95Ib7aHBlOcS3J8zm+1+kpcUyY3U/1Aw/qqgK?= =?us-ascii?Q?j0Rw7MBygsSm5j653d0d5mBZMtBYNrxGMlSjW7iWj0awyaAJMIi/Fb45zsBO?= =?us-ascii?Q?32Ko5J4IQ/UBKBHFQgPxs3ZQvj2fZJLzhl4pqh7lNS9wixrKxhcoj3aHSaln?= =?us-ascii?Q?28YzZwX7FJNo1FG7geFEU/k7e9iKZjJaYMpCyRsMMq0a3eSDWJRcXxnQjrI0?= =?us-ascii?Q?Ty0HJ2BX+s5Llmaekl8UpK3TLqvowl0Xe3LWk1RiVRrUhHxI+5DBhccNO286?= =?us-ascii?Q?FdqVTFL0b5JLF/apehsITeXox73PLZTZnKnLIiB0Z7Huug2JQaKAEflncQvM?= =?us-ascii?Q?8b1Oi+i3j4VFyBCea2V/hoCGqjOrcJvHRU36wuJmXmGbPTjedI6+8CbuJ+hZ?= =?us-ascii?Q?R4VaOOCF9DtGRs45nSSt5CKdMHH5lCeXzbMjma0bVcmEvKwMZyAq6iqbdJgb?= =?us-ascii?Q?bJbIdcfWSJsgSAp9ieQI+z34GSw/KheFDAzJSHNsaAf9zanC958+CUiKKAeI?= =?us-ascii?Q?SeTm1DjrdEZYWN/lL9hk4UV/3sifOiseAg72Fe2Wx7ahV1gqXnUVnvGbKHV7?= =?us-ascii?Q?+QCBFjKlpJXmxhx8r1YvrEKxu5gSRQNx+IZ61aBbK08T5SK6xxeq7Oj9vQp7?= =?us-ascii?Q?DGLWq6TPkg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 64865cfb-a546-4db5-a944-08df2d7449f0 X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB7742.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Oct 2026 00:02:39.3146 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: RxF3+ry/3DAgsQFwSmDljD73bIayPDsnoCp3xbg6rvDaEJp90lTLsgBOvk71rcnYCaxUG/KXPTG309m4L26wtg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6171 On Sun, Oct 18, 2026 at 02:51:18AM +0000, Zqiang wrote: > > > > > > > > On Oct 15, 2026, at 5:46 AM, Zqiang wrote: > > > > > > The RCU Tasks Rude grace period is implemented by invoking the > > > schedule_on_each_cpu() with an empty work function, which forces > > > a context switch on every online CPU and guarantees that all > > > rude-tasks read-side critical sections have completed. However, > > > schedule_on_each_cpu() can fail (via alloc_percpu() returning > > > -ENOMEM) and returns immediately, in which case those context > > > switches never happen, too-short grace period happen. > > > > > > This commit therefore wraps the schedule_on_each_cpu() call in > > > WARN_ONCE() so that this failure is reported as a "Too-short > > > grace period" warning. > > > > > > Signed-off-by: Zqiang > > > --- > > > kernel/rcu/tasks.h | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h > > > index fcac7361ec51..91c25717402e 100644 > > > --- a/kernel/rcu/tasks.h > > > +++ b/kernel/rcu/tasks.h > > > @@ -1361,7 +1361,8 @@ static void rcu_tasks_be_rude(struct work_struct *work) > > > static void rcu_tasks_rude_wait_gp(struct rcu_tasks *rtp) > > > { > > > rtp->n_ipis += cpumask_weight(cpu_online_mask); > > > - schedule_on_each_cpu(rcu_tasks_be_rude); > > > + WARN_ONCE(schedule_on_each_cpu(rcu_tasks_be_rude), > > > + "%s: Too-short grace period, OOM is now expected behavior!!!\n", rtp->name); > > > > > Is that the best error message? OOM is expected when grace periods do not conclude. > > > > Hi, Joel > > I will resend v2, use DEFINE_PER_CPU() to replace alloc_percpu() to allocate work_struct objects. Thank you! Looking forward to it, Joel Fernandes