From: Vlastimil Babka <vbabka@xxxxxxx> Subject: mm, slab: shorten kmalloc cache names for large sizes Kmalloc cache names can get quite long for large object sizes, when the sizes are expressed in bytes. Use 'k' and 'M' prefixes to make the names as short as possible e.g. in /proc/slabinfo. This works, as we mostly use power-of-two sizes, with exceptions only below 1k. Example: 'kmalloc-4194304' becomes 'kmalloc-4M' Link: http://lkml.kernel.org/r/20180731090649.16028-7-vbabka@xxxxxxx Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Laura Abbott <labbott@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab_common.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) --- a/mm/slab_common.c~mm-slab-shorten-kmalloc-cache-names-for-large-sizes +++ a/mm/slab_common.c @@ -1050,15 +1050,15 @@ const struct kmalloc_info_struct kmalloc {"kmalloc-16", 16}, {"kmalloc-32", 32}, {"kmalloc-64", 64}, {"kmalloc-128", 128}, {"kmalloc-256", 256}, {"kmalloc-512", 512}, - {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048}, - {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192}, - {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768}, - {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072}, - {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288}, - {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152}, - {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608}, - {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432}, - {"kmalloc-67108864", 67108864} + {"kmalloc-1k", 1024}, {"kmalloc-2k", 2048}, + {"kmalloc-4k", 4096}, {"kmalloc-8k", 8192}, + {"kmalloc-16k", 16384}, {"kmalloc-32k", 32768}, + {"kmalloc-64k", 65536}, {"kmalloc-128k", 131072}, + {"kmalloc-256k", 262144}, {"kmalloc-512k", 524288}, + {"kmalloc-1M", 1048576}, {"kmalloc-2M", 2097152}, + {"kmalloc-4M", 4194304}, {"kmalloc-8M", 8388608}, + {"kmalloc-16M", 16777216}, {"kmalloc-32M", 33554432}, + {"kmalloc-64M", 67108864} }; /* @@ -1108,6 +1108,21 @@ void __init setup_kmalloc_cache_index_ta } } +static const char * +kmalloc_cache_name(const char *prefix, unsigned int size) +{ + + static const char units[3] = "\0kM"; + int idx = 0; + + while (size >= 1024 && (size % 1024 == 0)) { + size /= 1024; + idx++; + } + + return kasprintf(GFP_NOWAIT, "%s-%u%c", prefix, size, units[idx]); +} + static void __init new_kmalloc_cache(int idx, int type, slab_flags_t flags) { @@ -1115,7 +1130,7 @@ new_kmalloc_cache(int idx, int type, sla if (type == KMALLOC_RECLAIM) { flags |= SLAB_RECLAIM_ACCOUNT; - name = kasprintf(GFP_NOWAIT, "kmalloc-rcl-%u", + name = kmalloc_cache_name("kmalloc-rcl", kmalloc_info[idx].size); BUG_ON(!name); } else { @@ -1164,8 +1179,7 @@ void __init create_kmalloc_caches(slab_f if (s) { unsigned int size = kmalloc_size(i); - char *n = kasprintf(GFP_NOWAIT, - "dma-kmalloc-%u", size); + const char *n = kmalloc_cache_name("dma-kmalloc", size); BUG_ON(!n); kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( _
