Re: [PATCH v2 2/2] crash: update stale NR_CPUS_DEFAULT references in elfcorehdr sizing docs

[Bradley Morgan]

On 25 August 2026 08:50:43 BST, "Ionut Nechita (Wind River)"
<ionut.nechita@xxxxxxxxxxxxx> wrote:
>From: Ionut Nechita <ionut.nechita@xxxxxxxxxxxxx>
>
>The elfcorehdr over-allocation for crash hotplug is now computed from
>CONFIG_NR_CPUS rather than CONFIG_NR_CPUS_DEFAULT, but two pieces of
>documentation still name the old symbol: the comment above
>crash_handle_hotplug_event() and the CRASH_MAX_MEMORY_RANGES help text.
>
>Update both so they describe what the code actually does and do not
>mislead people sizing CRASH_MAX_MEMORY_RANGES.
>
>Documentation only, no functional change.
>
>Suggested-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
>Suggested-by: Bradley Morgan <include@xxxxxxxxx>

Reviewed-by: Bradley Morgan <include@xxxxxxxxx>

You shockingly didn't CC me!1!1

>Signed-off-by: Ionut Nechita <ionut.nechita@xxxxxxxxxxxxx>
>---
> kernel/Kconfig.kexec | 2 +-
> kernel/crash_core.c  | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
>index 15632358bcf7..a97ed9605602 100644
>--- a/kernel/Kconfig.kexec
>+++ b/kernel/Kconfig.kexec
>@@ -167,7 +167,7 @@ config CRASH_MAX_MEMORY_RANGES
> 	  memory regions that the elfcorehdr buffer/segment can accommodate.
> 	  These regions are obtained via walk_system_ram_res(); eg. the
> 	  'System RAM' entries in /proc/iomem.
>-	  This value is combined with NR_CPUS_DEFAULT and multiplied by
>+	  This value is combined with NR_CPUS and multiplied by
> 	  sizeof(Elf64_Phdr) to determine the final elfcorehdr memory buffer/
> 	  segment size.
> 	  The value 8192, for example, covers a (sparsely populated) 1TiB system
>diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>index 2b36aa9fade0..d0bd2d0cf899 100644
>--- a/kernel/crash_core.c
>+++ b/kernel/crash_core.c
>@@ -648,7 +648,7 @@ int crash_check_hotplug_support(void)
>  * new list of CPUs and memory. To make changes to the elfcorehdr, it
>  * should be large enough to permit a growing number of CPU and Memory
>  * resources. One can estimate the elfcorehdr memory size based on
>- * NR_CPUS_DEFAULT and CRASH_MAX_MEMORY_RANGES. The elfcorehdr is
>+ * NR_CPUS and CRASH_MAX_MEMORY_RANGES. The elfcorehdr is
>  * excluded from SHA verification by default if the architecture
>  * supports crash hotplug.
>  */
>


Thanks!