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Thu, 29 Jan 2026 08:21:05 -0800 (PST) Date: Thu, 29 Jan 2026 17:21:02 +0100 From: Petr Mladek To: Pnina Feder Cc: akpm@linux-foundation.org, bhe@redhat.com, linux-kernel@vger.kernel.org, lkp@intel.com, mgorman@suse.de, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, tglx@linutronix.de, vkondra@mobileye.com Subject: Re: [PATCH v8] panic: add panic_force_cpu= parameter to redirect panic to a specific CPU Message-ID: References: <20260122102457.1154599-1-pnina.feder@mobileye.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260122102457.1154599-1-pnina.feder@mobileye.com> On Thu 2026-01-22 12:24:57, Pnina Feder wrote: > Some platforms require panic handling to execute on a specific CPU for > crash dump to work reliably. This can be due to firmware limitations, > interrupt routing constraints, or platform-specific requirements where > only a single CPU is able to safely enter the crash kernel. > > Add the panic_force_cpu= kernel command-line parameter to redirect panic > execution to a designated CPU. When the parameter is provided, the CPU > that initially triggers panic forwards the panic context to the target > CPU via IPI, which then proceeds with the normal panic and kexec flow. > > The IPI delivery is implemented as a weak function (panic_smp_redirect_cpu) > so architectures with NMI support can override it for more reliable delivery. > > If the specified CPU is invalid, offline, or a panic is already in > progress on another CPU, the redirection is skipped and panic continues > on the current CPU. > > Signed-off-by: Pnina Feder I can't see any obvious problem any longer ;-) Feel free to use: Reviewed-by: Petr Mladek Best Regards, Petr