[Crash-utility] Re: [PATCH 2/2] Fix "kmem [-s]" command on Linux 7.1 and later

Hi Dave, thank you for testing the patches. On 2026/08/10 19:39, Dave Young wrote: hmm, based on the kernel patches and the observed behavior, I suspect this makedumpfile patch, which fixes a wrong exclusion on Linux 7.1. https://github.com/makedumpfile/makedumpfile/commit/f50c015f150f93dc69f81... Does your makedumpfile include this patch? Thanks, Kazu >> >> Attached the kernel config, it is a very small config I tuned for testing with a kvm guest. If you need more info just let me know. >> >> >> >> On 8/2/26 1:15 PM, Dave Young wrote: >>> Add Kairui and Baoquan who could help to review the patch >>> >>> On 7/24/26 9:27 AM, HAGIO KAZUHITO(萩尾 一仁) wrote: >>>> From: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; >>>> >>>> Kernel commit 5ba6bc27b1f9 ("slab: decouple pointer to barn from >>>> kmem_cache_node") changed kmem_cache.node array into struct >>>> kmem_cache_per_node_ptrs kmem_cache.per_node array. >>>> >>>> Without the patch, "kmem <slab address>" and "kmem -s" option fail with >>>> the following error. >>>> >>>> crash> kmem -s >>>> >>>> kmem: invalid structure member offset: kmem_cache_local_node >>>> FILE: memory.c LINE: 19563 FUNCTION: get_kmem_cache_slub_data() >>>> >>>> Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; >>>> --- >>>> This patch needs to be applied on the top of the patch [1], so 2/2. >>>> [1] [PATCH] Fix compound_head() and "bt -F" option on Linux 7.1 and later >>>> https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg02256.html >>>> >>>> defs.h | 3 +++ >>>> memory.c | 19 +++++++++++++++---- >>>> symbols.c | 4 ++++ >>>> 3 files changed, 22 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/defs.h b/defs.h >>>> index 88b7bbeb2372..ef34db90113f 100644 >>>> --- a/defs.h >>>> +++ b/defs.h >>>> @@ -2296,6 +2296,8 @@ struct offset_table { /* stash of commonly-used offsets */ >>>> long folio__folio_order; >>>> long folio__flags_1; >>>> long page_compound_info; >>>> + long kmem_cache_per_node; >>>> + long kmem_cache_per_node_ptrs_node; >>>> }; >>>> >>>> struct size_table { /* stash of commonly-used sizes */ >>>> @@ -2478,6 +2480,7 @@ struct size_table { /* stash of commonly-used sizes */ >>>> long page_compound_order; >>>> long folio__folio_order; >>>> long folio__flags_1; >>>> + long kmem_cache_per_node_ptrs; >>>> }; >>>> >>>> struct array_table { >>>> diff --git a/memory.c b/memory.c >>>> index 7102e951f1d5..7c3ab506217a 100644 >>>> --- a/memory.c >>>> +++ b/memory.c >>>> @@ -871,6 +871,8 @@ vm_init(void) >>>> MEMBER_OFFSET_INIT(kmem_cache_inuse, "kmem_cache", "inuse"); >>>> MEMBER_OFFSET_INIT(kmem_cache_align, "kmem_cache", "align"); >>>> MEMBER_OFFSET_INIT(kmem_cache_node, "kmem_cache", "node"); >>>> + if (INVALID_MEMBER(kmem_cache_node)) >>>> + MEMBER_OFFSET_INIT(kmem_cache_per_node, "kmem_cache", "per_node"); >>>> MEMBER_OFFSET_INIT(kmem_cache_cpu_slab, "kmem_cache", "cpu_slab"); >>>> MEMBER_OFFSET_INIT(kmem_cache_list, "kmem_cache", "list"); >>>> MEMBER_OFFSET_INIT(kmem_cache_red_left_pad, "kmem_cache", "red_left_pad"); >>>> @@ -922,7 +924,12 @@ vm_init(void) >>>> if (INVALID_MEMBER(page_objects)) >>>> ANON_MEMBER_OFFSET_INIT(page_objects, "slab", "objects"); >>>> } >>>> - if (VALID_MEMBER(kmem_cache_node)) { >>>> + if (VALID_MEMBER(kmem_cache_per_node)) { /* Linux 7.1 and later */ >>>> + MEMBER_OFFSET_INIT(kmem_cache_per_node_ptrs_node, >>>> + "kmem_cache_per_node_ptrs", "node"); >>>> + STRUCT_SIZE_INIT(kmem_cache_per_node_ptrs, "kmem_cache_per_node_ptrs"); >>>> + vt->flags |= CONFIG_NUMA; >>>> + } else if (VALID_MEMBER(kmem_cache_node)) { >>>> ARRAY_LENGTH_INIT(len, NULL, "kmem_cache.node", NULL, 0); >>>> vt->flags |= CONFIG_NUMA; >>>> } >>>> @@ -19555,9 +19562,13 @@ get_kmem_cache_slub_data(long cmd, struct meminfo *si) >>>> for (n = 0; n < vt->numnodes; n++) { >>>> if (vt->flags & CONFIG_NUMA) { >>>> nt = &vt->node_table[n]; >>>> - node_ptr = ULONG(si->cache_buf + >>>> - OFFSET(kmem_cache_node) + >>>> - (sizeof(void *) * nt->node_id)); >>>> + if (VALID_MEMBER(kmem_cache_per_node)) /* Linux 7.1 and later */ >>>> + node_ptr = ULONG(si->cache_buf + OFFSET(kmem_cache_per_node) + >>>> + (SIZE(kmem_cache_per_node_ptrs) * nt->node_id) + >>>> + OFFSET(kmem_cache_per_node_ptrs_node)); >>>> + else >>>> + node_ptr = ULONG(si->cache_buf + OFFSET(kmem_cache_node) + >>>> + (sizeof(void *) * nt->node_id)); >>>> } else >>>> node_ptr = si->cache + >>>> OFFSET(kmem_cache_local_node); >>>> diff --git a/symbols.c b/symbols.c >>>> index 2071bdf77819..ae7fa7b416a4 100644 >>>> --- a/symbols.c >>>> +++ b/symbols.c >>>> @@ -10932,6 +10932,9 @@ dump_offset_table(char *spec, ulong makestruct) >>>> OFFSET(kmem_cache_oo)); >>>> fprintf(fp, " kmem_cache_random: %ld\n", >>>> OFFSET(kmem_cache_random)); >>>> + fprintf(fp, " kmem_cache_per_node: %ld\n", OFFSET(kmem_cache_per_node)); >>>> + >>>> + fprintf(fp, " kmem_cache_per_node_ptrs_node: %ld\n", OFFSET(kmem_cache_per_node_ptrs_node)); >>>> >>>> fprintf(fp, " kmem_cache_node_nr_partial: %ld\n", >>>> OFFSET(kmem_cache_node_nr_partial)); >>>> @@ -12043,6 +12046,7 @@ dump_offset_table(char *spec, ulong makestruct) >>>> fprintf(fp, " kmem_cache: %ld\n", SIZE(kmem_cache)); >>>> fprintf(fp, " kmem_cache_node: %ld\n", SIZE(kmem_cache_node)); >>>> fprintf(fp, " kmem_cache_cpu: %ld\n", SIZE(kmem_cache_cpu)); >>>> + fprintf(fp, " kmem_cache_per_node_ptrs: %ld\n", SIZE(kmem_cache_per_node_ptrs)); >>>> >>>> fprintf(fp, " swap_info_struct: %ld\n", >>>> SIZE(swap_info_struct)); >>> -- >>> Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io >>> To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io >>> https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ >>> Contribution Guidelines: https://github.com/crash-utility/crash/wiki >>> >>> -- >>> Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io >>> To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io >>> https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ >>> Contribution Guidelines: https://github.com/crash-utility/crash/wiki