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Date: Tue, 19 Sep 2017 13:57:15 -0700 (PDT) From: David Rientjes <rientjes@...gle.com> To: Yang Shi <yang.s@...baba-inc.com> cc: cl@...ux.com, penberg@...nel.org, iamjoonsoo.kim@....com, akpm@...ux-foundation.org, mhocko@...nel.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH 2/2] mm: oom: show unreclaimable slab info when kernel panic On Tue, 19 Sep 2017, Yang Shi wrote: > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -35,6 +35,8 @@ > static DECLARE_WORK(slab_caches_to_rcu_destroy_work, > slab_caches_to_rcu_destroy_workfn); > > +#define K(x) ((x)/1024) > + > /* > * Set of flags that will prevent slab merging > */ > @@ -1272,6 +1274,34 @@ static int slab_show(struct seq_file *m, void *p) > return 0; > } > > +void show_unreclaimable_slab() > +{ > + struct kmem_cache *s = NULL; > + struct slabinfo sinfo; > + > + memset(&sinfo, 0, sizeof(sinfo)); > + > + printk("Unreclaimable slabs:\n"); > + > + /* > + * Here acquiring slab_mutex is unnecessary since we don't prefer to > + * get sleep in oom path right before kernel panic, and avoid race condition. > + * Since it is already oom, so there should be not any big allocation > + * which could change the statistics significantly. > + */ > + list_for_each_entry(s, &slab_caches, list) { > + if (!is_root_cache(s)) > + continue; > + > + get_slabinfo(s, &sinfo); > + > + if (!is_reclaimable(s) && sinfo.num_objs > 0) > + printk("%-17s %luKB\n", cache_name(s), K(sinfo.num_objs * s->size)); > + } I like this, but could we be even more helpful by giving the user more information from sinfo beyond just the total size of objects allocated?
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