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/[email protected] Suggested-by: Matthew Wilcox <[email protected]> Signed-off-by: Vlastimil Babka <[email protected]> Acked-by: Mel Gorman <[email protected]> Acked-by: Christoph Lameter <[email protected]> Acked-by: Roman Gushchin <[email protected]> Cc: David Rientjes <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Sumit Semwal <[email protected]> Cc: Vijayanand Jitta <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Oct 26, 2018 · f0d7787 · f0d7787
1 parent 61f94e1
commit f0d7787
Showing 1 changed file with 26 additions and 12 deletions.
diff --git a/mm/slab_common.c b/mm/slab_common.c
@@ -1050,15 +1050,15 @@ const struct kmalloc_info_struct kmalloc_info[] __initconst = {
 	{"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}
 };
 
 /*
@@ -1108,14 +1108,29 @@ void __init setup_kmalloc_cache_index_table(void)
 	}
 }
 
+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)
 {
 	const char *name;
 
 	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_flags_t flags)
 
 		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(