Re: [PATCH v3 12/17] x86/crash: Use num_possible_cpus() for elfcorehdr size
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From: Sourabh Jain <hidden>
Date: 2026-09-02 06:15:34
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kexec, linux-fsdevel, linux-mm, lkml, loongarch
Hello Jinjie, This patch makes the below patch redundant.. https://lore.kernel.org/all/20260826073527.21487-2-ionut.nechita@windriver.com/ (local) I suggest dropping the first patch from the above series and including the second patch from that series in this patch series with the updated comment. - Sourabh Jain On 26/08/26 14:55, Jinjie Ruan wrote:
quoted hunk ↗ jump to hunk
Use num_possible_cpus() instead of CONFIG_NR_CPUS to calculate the elfcorehdr buffer size, matching what crash_prepare_elf64_headers() already uses for the actual header content. This avoids over-allocation when the system has fewer possible CPUs than the compile-time limit, and aligns x86 with PowerPC. Signed-off-by: Jinjie Ruan <redacted> --- arch/x86/kernel/crash.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index a3bf786286d4..afe2aea19f47 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c@@ -369,9 +369,9 @@ int crash_load_segments(struct kimage *image) * maximum CPUs and maximum memory ranges. */ if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) - pnum = 2 + CONFIG_NR_CPUS + CONFIG_CRASH_MAX_MEMORY_RANGES; + pnum = 2 + num_possible_cpus() + CONFIG_CRASH_MAX_MEMORY_RANGES; else - pnum += 2 + CONFIG_NR_CPUS; + pnum += 2 + num_possible_cpus(); if (pnum < (unsigned long)PN_XNUM) { kbuf.memsz = elf64_phdr_size(pnum);@@ -429,7 +429,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void) unsigned int sz; /* kernel_map, VMCOREINFO and maximum CPUs */ - sz = 2 + CONFIG_NR_CPUS; + sz = 2 + num_possible_cpus(); if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) sz += CONFIG_CRASH_MAX_MEMORY_RANGES; sz *= sizeof(Elf64_Phdr);