From: Eric DeVolder <eric.devolder@oracle.com> To: linux-kernel@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, ebiederm@xmission.com, dyoung@redhat.com, bhe@redhat.com, vgoyal@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, nramas@linux.microsoft.com, thomas.lendacky@amd.com, robh@kernel.org, efault@gmx.de, rppt@kernel.org, david@redhat.com, sourabhjain@linux.ibm.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, eric.devolder@oracle.com Subject: [PATCH v9 5/7] kexec: exclude hot remove cpu from elfcorehdr notes Date: Mon, 13 Jun 2022 18:42:38 -0400 [thread overview] Message-ID: <20220613224240.79400-6-eric.devolder@oracle.com> (raw) In-Reply-To: <20220613224240.79400-1-eric.devolder@oracle.com> Due to use of CPUHP_AP_ONLINE_DYN, upon CPU unplug, the CPU is still in the for_each_present_cpu() list when within the handle_hotplug_event(). Thus the CPU must be explicitly excluded when building the new list of CPUs. This change identifies in handle_hotplug_event() the CPU to be excluded, and the check for excluding the CPU in crash_prepare_elf64_headers(). Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Acked-by: Baoquan He <bhe@redhat.com> --- kernel/crash_core.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 84eb10a4241f..47f667df1c0b 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -358,6 +358,11 @@ int crash_prepare_elf64_headers(struct kimage *image, struct crash_mem *mem, /* Prepare one phdr of type PT_NOTE for each present CPU */ for_each_present_cpu(cpu) { +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG) + /* Skip the soon-to-be offlined cpu */ + if (image->hotplug_event && (cpu == image->offlinecpu)) + continue; +#endif phdr->p_type = PT_NOTE; notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); phdr->p_offset = phdr->p_paddr = notes_addr; @@ -650,6 +655,16 @@ static void handle_hotplug_event(unsigned int hp_action, unsigned int cpu) /* Flag to differentiate between normal load and hotplug */ image->hotplug_event = true; + /* + * Due to use of CPUHP_AP_ONLINE_DYN, upon unplug and during + * this callback, the CPU is still in the for_each_present_cpu() + * list. Must explicitly look to exclude this CPU when building + * new list. + */ + image->offlinecpu = + (hp_action == KEXEC_CRASH_HP_REMOVE_CPU) ? + cpu : KEXEC_CRASH_HP_INVALID_CPU; + /* Now invoke arch-specific update handler */ arch_crash_handle_hotplug_event(image, hp_action, cpu); -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Eric DeVolder <eric.devolder@oracle.com> To: linux-kernel@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, ebiederm@xmission.com, dyoung@redhat.com, bhe@redhat.com, vgoyal@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, nramas@linux.microsoft.com, thomas.lendacky@amd.com, robh@kernel.org, efault@gmx.de, rppt@kernel.org, david@redhat.com, sourabhjain@linux.ibm.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, eric.devolder@oracle.com Subject: [PATCH v9 5/7] kexec: exclude hot remove cpu from elfcorehdr notes Date: Mon, 13 Jun 2022 18:42:38 -0400 [thread overview] Message-ID: <20220613224240.79400-6-eric.devolder@oracle.com> (raw) In-Reply-To: <20220613224240.79400-1-eric.devolder@oracle.com> Due to use of CPUHP_AP_ONLINE_DYN, upon CPU unplug, the CPU is still in the for_each_present_cpu() list when within the handle_hotplug_event(). Thus the CPU must be explicitly excluded when building the new list of CPUs. This change identifies in handle_hotplug_event() the CPU to be excluded, and the check for excluding the CPU in crash_prepare_elf64_headers(). Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Acked-by: Baoquan He <bhe@redhat.com> --- kernel/crash_core.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 84eb10a4241f..47f667df1c0b 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -358,6 +358,11 @@ int crash_prepare_elf64_headers(struct kimage *image, struct crash_mem *mem, /* Prepare one phdr of type PT_NOTE for each present CPU */ for_each_present_cpu(cpu) { +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG) + /* Skip the soon-to-be offlined cpu */ + if (image->hotplug_event && (cpu == image->offlinecpu)) + continue; +#endif phdr->p_type = PT_NOTE; notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); phdr->p_offset = phdr->p_paddr = notes_addr; @@ -650,6 +655,16 @@ static void handle_hotplug_event(unsigned int hp_action, unsigned int cpu) /* Flag to differentiate between normal load and hotplug */ image->hotplug_event = true; + /* + * Due to use of CPUHP_AP_ONLINE_DYN, upon unplug and during + * this callback, the CPU is still in the for_each_present_cpu() + * list. Must explicitly look to exclude this CPU when building + * new list. + */ + image->offlinecpu = + (hp_action == KEXEC_CRASH_HP_REMOVE_CPU) ? + cpu : KEXEC_CRASH_HP_INVALID_CPU; + /* Now invoke arch-specific update handler */ arch_crash_handle_hotplug_event(image, hp_action, cpu); -- 2.31.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2022-06-13 22:44 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-13 22:42 [PATCH v9 0/7] crash: Kernel handling of CPU and memory hot un/plug Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 1/7] crash: move crash_prepare_elf64_headers Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 2/7] crash: prototype change for crash_prepare_elf64_headers Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 3/7] crash: add generic infrastructure for crash hotplug support Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 4/7] kexec: exclude elfcorehdr from the segment digest Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder [this message] 2022-06-13 22:42 ` [PATCH v9 5/7] kexec: exclude hot remove cpu from elfcorehdr notes Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 6/7] crash: memory and cpu hotplug sysfs attributes Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-13 22:42 ` [PATCH v9 7/7] x86/crash: Add x86 crash hotplug support Eric DeVolder 2022-06-13 22:42 ` Eric DeVolder 2022-06-20 5:06 ` Sourabh Jain 2022-06-20 5:06 ` Sourabh Jain 2022-07-07 12:55 ` Eric DeVolder 2022-07-07 12:55 ` Eric DeVolder 2022-07-11 9:57 ` Baoquan He 2022-07-11 9:57 ` Baoquan He 2022-07-12 20:31 ` Eric DeVolder 2022-07-12 20:31 ` Eric DeVolder 2022-07-08 19:38 ` Fabio M. De Francesco 2022-07-08 19:38 ` Fabio M. De Francesco 2022-07-08 21:07 ` Eric DeVolder 2022-07-08 21:07 ` Eric DeVolder 2022-07-09 18:41 ` Fabio M. De Francesco 2022-07-09 18:41 ` Fabio M. De Francesco 2022-07-05 15:17 ` [PATCH v9 0/7] crash: Kernel handling of CPU and memory hot un/plug Eric DeVolder 2022-07-05 15:17 ` Eric DeVolder 2022-07-06 1:16 ` Baoquan He 2022-07-06 1:16 ` Baoquan He 2022-07-07 13:05 ` Eric DeVolder 2022-07-07 13:05 ` Eric DeVolder 2022-07-20 19:08 ` Eric DeVolder 2022-07-20 19:08 ` Eric DeVolder 2022-07-21 0:07 ` Baoquan He 2022-07-21 0:07 ` Baoquan He
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