lkml.org 
[lkml]   [2012]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v3] mm: SLAB Out-of-memory diagnostics
    From
    Date
    On Fri, 2012-03-09 at 17:27 -0300, Rafael Aquini wrote:
    > Following the example at mm/slub.c, add out-of-memory diagnostics to the
    > SLAB allocator to help on debugging certain OOM conditions.
    >
    > An example print out looks like this:
    >
    > <snip page allocator out-of-memory message>
    > SLAB: Unable to allocate memory on node 0 (gfp=0x11200)
    > cache: bio-0, object size: 192, order: 0
    > node 0: slabs: 3/3, objs: 60/60, free: 0

    Should probably be :

    node: 0 slabs: 3/3, objs: 60/60, free: 0


    >
    > Signed-off-by: Rafael Aquini <aquini@redhat.com>
    > Acked-by: Rik van Riel <riel@redhat.com>
    > ---
    > v2:
    > * drop the sysctl knob to override __GFP_NOWARN allocation flag (Pekka, David)
    >
    > v3:
    > * adjust the print output to match slub's warning printout (WANG Cong)
    >
    > mm/slab.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
    > 1 files changed, 50 insertions(+), 1 deletions(-)
    >
    > diff --git a/mm/slab.c b/mm/slab.c
    > index f0bd785..cda1ff6 100644
    > --- a/mm/slab.c
    > +++ b/mm/slab.c
    > @@ -1731,6 +1731,52 @@ static int __init cpucache_init(void)
    > }
    > __initcall(cpucache_init);
    >
    > +static noinline void
    > +slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
    > +{
    > + struct kmem_list3 *l3;
    > + struct slab *slabp;
    > + unsigned long flags;
    > + int node;
    > +
    > + printk(KERN_WARNING
    > + "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
    > + nodeid, gfpflags);
    > + printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n",
    > + cachep->name, cachep->buffer_size, cachep->gfporder);
    > +
    > + for_each_online_node(node) {
    > + unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
    > + unsigned long active_slabs = 0, num_slabs = 0;
    > +
    > + l3 = cachep->nodelists[node];
    > + if (!l3)
    > + continue;
    > +
    > + spin_lock_irqsave(&l3->list_lock, flags);
    > + list_for_each_entry(slabp, &l3->slabs_full, list) {
    > + active_objs += cachep->num;
    > + active_slabs++;
    > + }
    > + list_for_each_entry(slabp, &l3->slabs_partial, list) {
    > + active_objs += slabp->inuse;
    > + active_slabs++;
    > + }
    > + list_for_each_entry(slabp, &l3->slabs_free, list)
    > + num_slabs++;
    > +
    > + free_objects += l3->free_objects;
    > + spin_unlock_irqrestore(&l3->list_lock, flags);
    > +
    > + num_slabs += active_slabs;
    > + num_objs = num_slabs * cachep->num;
    > + printk(KERN_WARNING
    > + " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",

    Probably should be :
    " node: %d slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",

    > + node, active_slabs, num_slabs, active_objs, num_objs,
    > + free_objects);
    > + }
    > +}
    > +
    > /*
    > * Interface to system's page allocator. No need to hold the cache-lock.
    > *
    > @@ -1757,8 +1803,11 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
    > flags |= __GFP_RECLAIMABLE;
    >
    > page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
    > - if (!page)
    > + if (!page) {
    > + if (!(flags & __GFP_NOWARN) && printk_ratelimit())
    > + slab_out_of_memory(cachep, flags, nodeid);
    > return NULL;
    > + }
    >
    > nr_pages = (1 << cachep->gfporder);
    > if (cachep->flags & SLAB_RECLAIM_ACCOUNT)




    \
     
     \ /
      Last update: 2012-03-10 01:27    [W:0.027 / U:0.148 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site