From 8147bc15b409c8ca52e98c6692273dd9bc5c6905 Mon Sep 17 00:00:00 2001 From: Yueyang Pan Date: Wed, 3 Sep 2025 04:16:14 -0700 Subject: [PATCH] mm/show_mem: add trylock while printing alloc info In production, show_mem() can be called concurrently from two different entities, for example one from oom_kill_process() another from __alloc_pages_slowpath from another kthread. This patch adds a spinlock and invokes trylock before printing out the kernel alloc info in show_mem(). This way two alloc info won't interleave with each other, which then makes parsing easier. Link: https://lkml.kernel.org/r/4ed91296e0c595d945a38458f7a8d9611b0c1e52.1756897825.git.pyyjason@gmail.com Signed-off-by: Yueyang Pan Acked-by: Usama Arif Acked-by: Vlastimil Babka Acked-by: Zi Yan Acked-by: Suren Baghdasaryan Acked-by: Shakeel Butt Cc: Brendan Jackman Cc: Johannes Weiner Cc: Michal Hocko Cc: Vishal Moola (Oracle) Signed-off-by: Andrew Morton --- mm/show_mem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/show_mem.c b/mm/show_mem.c index 22bb8b045671a..90a9a37116e78 100644 --- a/mm/show_mem.c +++ b/mm/show_mem.c @@ -425,7 +425,9 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx) printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages)); #endif #ifdef CONFIG_MEM_ALLOC_PROFILING - { + static DEFINE_SPINLOCK(mem_alloc_profiling_spinlock); + + if (spin_trylock(&mem_alloc_profiling_spinlock)) { struct codetag_bytes tags[10]; size_t i, nr; @@ -452,6 +454,7 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx) ct->lineno, ct->function); } } + spin_unlock(&mem_alloc_profiling_spinlock); } #endif } -- 2.47.3