lkml.org 
[lkml]   [2020]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v2 sl-b 3/5] mm: Make mem_dump_obj() handle vmalloc() memory
    From
    Date
    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>

    ...

    > --- 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)
    >

    \
     
     \ /
      Last update: 2020-12-09 18:53    [W:8.404 / U:0.020 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site