From: Baoquan He <bhe@redhat.com>
To: kexec@lists.infradead.org
Subject: [PATCH v8 5/7] kexec: exclude hot remove cpu from elfcorehdr notes
Date: Wed, 11 May 2022 18:13:09 +0800 [thread overview]
Message-ID: <20220511101309.GI122876@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20220505184603.1548-6-eric.devolder@oracle.com>
On 05/05/22 at 02:46pm, Eric DeVolder wrote:
> 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>
LGTM,
Acked-by: Baoquan He <bhe@redhat.com>
> ---
> kernel/crash_core.c | 10 ++++++++++
> kernel/kexec_file.c | 5 +++++
> 2 files changed, 15 insertions(+)
>
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index f197af50def6..7ba43f058d82 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -520,6 +520,16 @@ static void handle_hotplug_event(unsigned int hp_action, unsigned int cpu)
> /* Flag to differentiate between normal load and hotplug */
> kexec_crash_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.
> + */
> + kexec_crash_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(kexec_crash_image, hp_action, cpu);
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index aacdf93c3507..d68e5769b428 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -1314,6 +1314,11 @@ 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;
> --
> 2.27.0
>
next prev parent reply other threads:[~2022-05-11 10:13 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-05 18:45 [PATCH v8 0/7] crash: Kernel handling of CPU and memory hot un/plug Eric DeVolder
2022-05-05 18:45 ` [PATCH v8 1/7] x86/crash: fix minor typo/bug in debug message Eric DeVolder
[not found] ` <72764a3c-8b8c-8652-945e-9b15f31cda15@linux.ibm.com>
2022-05-09 5:26 ` Baoquan He
2022-05-09 15:41 ` Eric DeVolder
2022-05-05 18:45 ` [PATCH v8 2/7] crash: prototype change for crash_prepare_elf64_headers Eric DeVolder
2022-05-12 8:42 ` David Hildenbrand
2022-05-12 16:10 ` Eric DeVolder
2022-05-05 18:45 ` [PATCH v8 3/7] crash: add generic infrastructure for crash hotplug support Eric DeVolder
2022-05-06 7:12 ` Baoquan He
2022-05-09 15:43 ` Eric DeVolder
2022-05-11 10:09 ` Baoquan He
2022-05-12 8:52 ` David Hildenbrand
2022-05-12 16:10 ` Eric DeVolder
2022-05-31 13:15 ` David Hildenbrand
2022-05-31 22:25 ` Eric DeVolder
2022-06-15 9:53 ` David Hildenbrand
2022-05-23 8:36 ` Sourabh Jain
2022-05-23 15:04 ` Eric DeVolder
2022-05-05 18:46 ` [PATCH v8 4/7] kexec: exclude elfcorehdr from the segment digest Eric DeVolder
2022-05-11 10:11 ` Baoquan He
2022-05-05 18:46 ` [PATCH v8 5/7] kexec: exclude hot remove cpu from elfcorehdr notes Eric DeVolder
2022-05-11 10:13 ` Baoquan He [this message]
2022-05-05 18:46 ` [PATCH v8 6/7] x86/crash: Add x86 crash hotplug support for kexec_file_load Eric DeVolder
2022-05-25 5:25 ` Sourabh Jain
2022-05-25 13:51 ` Eric DeVolder
2022-05-05 18:46 ` [PATCH v8 7/7] x86/crash: Add x86 crash hotplug support for kexec_load Eric DeVolder
2022-05-25 14:26 ` Sourabh Jain
2022-05-31 22:18 ` Eric DeVolder
2022-05-25 15:13 ` [PATCH v8 0/7] crash: Kernel handling of CPU and memory hot un/plug Sourabh Jain
2022-05-26 13:16 ` Eric DeVolder
2022-05-26 13:39 ` Sourabh Jain
2022-05-26 13:44 ` Eric DeVolder
2022-05-31 13:18 ` David Hildenbrand
2022-05-31 22:22 ` Eric DeVolder
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