Markus Elfring <Markus.Elfring@xxxxxx> writes: >>>> Please just remove the message instead, it's a tiny allocation that's >>>> unlikely to ever fail, and the caller will print an error anyway. >>> >>> How do you think about to take another look at a previous update suggestion >>> like the following? >>> >>> powerpc/nvram: Delete three error messages for a failed memory allocation >>> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/00845261-8528-d011-d3b8-e9355a231d3a@xxxxxxxxxxxxxxxxxxxxx/ >>> https://lore.kernel.org/linuxppc-dev/00845261-8528-d011-d3b8-e9355a231d3a@xxxxxxxxxxxxxxxxxxxxx/ >>> https://lore.kernel.org/patchwork/patch/752720/ >>> https://lkml.org/lkml/2017/1/19/537 >> >> That deleted the messages from nvram_scan_partitions(), but neither of >> the callers of nvram_scan_paritions() check its return value or print >> anything if it fails. So removing those messages would make those >> failures silent which is not what we want. > > * How do you think about information like the following? > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=f359287765c04711ff54fbd11645271d8e5ff763#n883 > “… > These generic allocation functions all emit a stack dump on failure when used > without __GFP_NOWARN so there is no use in emitting an additional failure > message when NULL is returned. > …” Are you sure that's actually true? A quick look around in slub.c leads me to: slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) { #ifdef CONFIG_SLUB_DEBUG static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); int node; struct kmem_cache_node *n; if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slub_oom_rs)) return; pr_warn("SLUB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n", nid, gfpflags, &gfpflags); pr_warn(" cache: %s, object size: %u, buffer size: %u, default order: %u, min order: %u\n", s->name, s->object_size, s->size, oo_order(s->oo), oo_order(s->min)); if (oo_order(s->min) > get_order(s->object_size)) pr_warn(" %s debugging increased min order, use slub_debug=O to disable.\n", s->name); for_each_kmem_cache_node(s, node, n) { unsigned long nr_slabs; unsigned long nr_objs; unsigned long nr_free; nr_free = count_partial(n, count_free); nr_slabs = node_nr_slabs(n); nr_objs = node_nr_objs(n); pr_warn(" node %d: slabs: %ld, objs: %ld, free: %ld\n", node, nr_slabs, nr_objs, nr_free); } #endif } Which looks a lot like it won't print anything when CONFIG_SLUB_DEBUG=n. But maybe I'm looking in the wrong place? cheers
