Re: [PATCH 1/1] alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output

[Johannes Weiner <hannes@cmpxchg.org>]

On Tue, Sep 09, 2025 at 04:49:42PM -0700, Suren Baghdasaryan wrote:
> While rare, memory allocation profiling can contain inaccurate counters
> if slab object extension vector allocation fails. That allocation might
> succeed later but prior to that, slab allocations that would have used
> that object extension vector will not be accounted for. To indicate
> incorrect counters, mark them with an asterisk in the /proc/allocinfo
> output.
> Bump up /proc/allocinfo version to reflect change in the file format.
> 
> Example output with invalid counters:
> allocinfo - version: 2.0
>            0        0 arch/x86/kernel/kdebugfs.c:105 func:create_setup_data_nodes
>            0        0 arch/x86/kernel/alternative.c:2090 func:alternatives_smp_module_add
>           0*       0* arch/x86/kernel/alternative.c:127 func:__its_alloc
>            0        0 arch/x86/kernel/fpu/regset.c:160 func:xstateregs_set
>            0        0 arch/x86/kernel/fpu/xstate.c:1590 func:fpstate_realloc
>            0        0 arch/x86/kernel/cpu/aperfmperf.c:379 func:arch_enable_hybrid_capacity_scale
>            0        0 arch/x86/kernel/cpu/amd_cache_disable.c:258 func:init_amd_l3_attrs
>       49152*      48* arch/x86/kernel/cpu/mce/core.c:2709 func:mce_device_create
>        32768        1 arch/x86/kernel/cpu/mce/genpool.c:132 func:mce_gen_pool_create
>            0        0 arch/x86/kernel/cpu/mce/amd.c:1341 func:mce_threshold_create_device
> 
> Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Thanks Suren!