Messages in this thread | | | Subject | Re: [PATCH v2 sl-b 3/5] mm: Make mem_dump_obj() handle vmalloc() memory | From | Vlastimil Babka <> | Date | Wed, 9 Dec 2020 18:51:20 +0100 |
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On 12/9/20 2:13 AM, paulmck@kernel.org wrote: > From: "Paul E. McKenney" <paulmck@kernel.org> > > This commit adds vmalloc() support to mem_dump_obj(). Note that the > vmalloc_dump_obj() function combines the checking and dumping, in > contrast with the split between kmem_valid_obj() and kmem_dump_obj(). > The reason for the difference is that the checking in the vmalloc() > case involves acquiring a global lock, and redundant acquisitions of > global locks should be avoided, even on not-so-fast paths. > > Note that this change causes on-stack variables to be reported as > vmalloc() storage from kernel_clone() or similar, depending on the degree > of inlining that your compiler does. This is likely more helpful than > the earlier "non-paged (local) memory". > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: <linux-mm@kvack.org> > Reported-by: Andrii Nakryiko <andrii@kernel.org> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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> --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3431,6 +3431,18 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > } > #endif /* CONFIG_SMP */ > > +bool vmalloc_dump_obj(void *object) > +{ > + struct vm_struct *vm; > + void *objp = (void *)PAGE_ALIGN((unsigned long)object); > + > + vm = find_vm_area(objp); > + if (!vm) > + return false; > + pr_cont(" vmalloc allocated at %pS\n", vm->caller);
Would it be useful to print the vm area boundaries too?
> + return true; > +} > + > #ifdef CONFIG_PROC_FS > static void *s_start(struct seq_file *m, loff_t *pos) > __acquires(&vmap_purge_lock) >
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