mm, slab: make kmalloc_info[] contain all types of names

Patch series "mm, slab: Make kmalloc_info[] contain all types of names", v6.

There are three types of kmalloc, KMALLOC_NORMAL, KMALLOC_RECLAIM
and KMALLOC_DMA.

The name of KMALLOC_NORMAL is contained in kmalloc_info[].name,
but the names of KMALLOC_RECLAIM and KMALLOC_DMA are dynamically
generated by kmalloc_cache_name().

Patch1 predefines the names of all types of kmalloc to save
the time spent dynamically generating names.

These changes make sense, and the time spent by new_kmalloc_cache()
has been reduced by approximately 36.3%.

                         Time spent by new_kmalloc_cache()
                                  (CPU cycles)
5.3-rc7                              66264
5.3-rc7+patch                        42188

This patch (of 3):

There are three types of kmalloc, KMALLOC_NORMAL, KMALLOC_RECLAIM and
KMALLOC_DMA.

The name of KMALLOC_NORMAL is contained in kmalloc_info[].name, but the
names of KMALLOC_RECLAIM and KMALLOC_DMA are dynamically generated by
kmalloc_cache_name().

This patch predefines the names of all types of kmalloc to save the time
spent dynamically generating names.

Besides, remove the kmalloc_cache_name() that is no longer used.

Link: http://lkml.kernel.org/r/1569241648-26908-2-git-send-email-lpf.vector@gmail.com
Signed-off-by: Pengfei Li <lpf.vector@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/slab.c b/mm/slab.c
index 66e5d80..66b3310 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1247,7 +1247,7 @@ void __init kmem_cache_init(void)
         * structures first.  Without this, further allocations will bug.
         */
        kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE] = create_kmalloc_cache(
-                               kmalloc_info[INDEX_NODE].name,
+                               kmalloc_info[INDEX_NODE].name[KMALLOC_NORMAL],
                                kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS,
                                0, kmalloc_size(INDEX_NODE));
        slab_state = PARTIAL_NODE;

diff --git a/mm/slab.h b/mm/slab.h
index b2b0169..8b77f97 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -139,7 +139,7 @@ extern struct kmem_cache *kmem_cache;
 
 /* A table of kmalloc cache names and sizes */
 extern const struct kmalloc_info_struct {
-       const char *name;
+       const char *name[NR_KMALLOC_TYPES];
        unsigned int size;
 } kmalloc_info[];
 

diff --git a/mm/slab_common.c b/mm/slab_common.c
index f9fb27b..68a8c29 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1139,26 +1139,56 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
        return kmalloc_caches[kmalloc_type(flags)][index];
 }
 
+#ifdef CONFIG_ZONE_DMA
+#define INIT_KMALLOC_INFO(__size, __short_size)                        \
+{                                                              \
+       .name[KMALLOC_NORMAL]  = "kmalloc-" #__short_size,      \
+       .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size,  \
+       .name[KMALLOC_DMA]     = "dma-kmalloc-" #__short_size,  \
+       .size = __size,                                         \
+}
+#else
+#define INIT_KMALLOC_INFO(__size, __short_size)                        \
+{                                                              \
+       .name[KMALLOC_NORMAL]  = "kmalloc-" #__short_size,      \
+       .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size,  \
+       .size = __size,                                         \
+}
+#endif
+
 /*
  * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
  * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
  * kmalloc-67108864.
  */
 const struct kmalloc_info_struct kmalloc_info[] __initconst = {
-       {NULL,                      0},         {"kmalloc-96",             96},
-       {"kmalloc-192",           192},         {"kmalloc-8",               8},
-       {"kmalloc-16",             16},         {"kmalloc-32",             32},
-       {"kmalloc-64",             64},         {"kmalloc-128",           128},
-       {"kmalloc-256",           256},         {"kmalloc-512",           512},
-       {"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}
+       INIT_KMALLOC_INFO(0, 0),
+       INIT_KMALLOC_INFO(96, 96),
+       INIT_KMALLOC_INFO(192, 192),
+       INIT_KMALLOC_INFO(8, 8),
+       INIT_KMALLOC_INFO(16, 16),
+       INIT_KMALLOC_INFO(32, 32),
+       INIT_KMALLOC_INFO(64, 64),
+       INIT_KMALLOC_INFO(128, 128),
+       INIT_KMALLOC_INFO(256, 256),
+       INIT_KMALLOC_INFO(512, 512),
+       INIT_KMALLOC_INFO(1024, 1k),
+       INIT_KMALLOC_INFO(2048, 2k),
+       INIT_KMALLOC_INFO(4096, 4k),
+       INIT_KMALLOC_INFO(8192, 8k),
+       INIT_KMALLOC_INFO(16384, 16k),
+       INIT_KMALLOC_INFO(32768, 32k),
+       INIT_KMALLOC_INFO(65536, 64k),
+       INIT_KMALLOC_INFO(131072, 128k),
+       INIT_KMALLOC_INFO(262144, 256k),
+       INIT_KMALLOC_INFO(524288, 512k),
+       INIT_KMALLOC_INFO(1048576, 1M),
+       INIT_KMALLOC_INFO(2097152, 2M),
+       INIT_KMALLOC_INFO(4194304, 4M),
+       INIT_KMALLOC_INFO(8388608, 8M),
+       INIT_KMALLOC_INFO(16777216, 16M),
+       INIT_KMALLOC_INFO(33554432, 32M),
+       INIT_KMALLOC_INFO(67108864, 64M)
 };
 
 /*
@@ -1208,36 +1238,14 @@ 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) {
+       if (type == KMALLOC_RECLAIM)
                flags |= SLAB_RECLAIM_ACCOUNT;
-               name = kmalloc_cache_name("kmalloc-rcl",
-                                               kmalloc_info[idx].size);
-               BUG_ON(!name);
-       } else {
-               name = kmalloc_info[idx].name;
-       }
 
-       kmalloc_caches[type][idx] = create_kmalloc_cache(name,
+       kmalloc_caches[type][idx] = create_kmalloc_cache(
+                                       kmalloc_info[idx].name[type],
                                        kmalloc_info[idx].size, flags, 0,
                                        kmalloc_info[idx].size);
 }
@@ -1279,11 +1287,10 @@ void __init create_kmalloc_caches(slab_flags_t flags)
 
                if (s) {
                        unsigned int size = kmalloc_size(i);
-                       const char *n = kmalloc_cache_name("dma-kmalloc", size);
 
-                       BUG_ON(!n);
                        kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
-                               n, size, SLAB_CACHE_DMA | flags, 0, 0);
+                               kmalloc_info[i].name[KMALLOC_DMA],
+                               size, SLAB_CACHE_DMA | flags, 0, 0);
                }
        }
 #endif