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From:   Pengfei Li <lpf.vector@gmail.com>
To:     akpm@linux-foundation.org
Cc:     vbabka@suse.cz, cl@linux.com, penberg@kernel.org,
        rientjes@google.com, iamjoonsoo.kim@lge.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, guro@fb.com,
        Pengfei Li <lpf.vector@gmail.com>
Subject: [PATCH v4 1/7] mm, slab: Make kmalloc_info[] contain all types of names
Date:   Mon, 16 Sep 2019 00:51:10 +0800
Message-Id: <20190915165121.7237-2-lpf.vector@gmail.com>
In-Reply-To: <20190915165121.7237-1-lpf.vector@gmail.com>
References: <20190915165121.7237-1-lpf.vector@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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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.

Signed-off-by: Pengfei Li <lpf.vector@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <guro@fb.com>
---
 mm/slab.c        |  2 +-
 mm/slab.h        |  2 +-
 mm/slab_common.c | 91 ++++++++++++++++++++++++++----------------------
 3 files changed, 51 insertions(+), 44 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 9df370558e5d..c42b6211f42e 100644
--- 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 9057b8056b07..2fc8f956906a 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -76,7 +76,7 @@ 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 807490fe217a..002e16673581 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1092,26 +1092,56 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
 	return kmalloc_caches[kmalloc_type(flags)][index];
 }
 
+#ifdef CONFIG_ZONE_DMA
+#define SET_KMALLOC_SIZE(__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 SET_KMALLOC_SIZE(__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}
+	SET_KMALLOC_SIZE(0, 0),
+	SET_KMALLOC_SIZE(96, 96),
+	SET_KMALLOC_SIZE(192, 192),
+	SET_KMALLOC_SIZE(8, 8),
+	SET_KMALLOC_SIZE(16, 16),
+	SET_KMALLOC_SIZE(32, 32),
+	SET_KMALLOC_SIZE(64, 64),
+	SET_KMALLOC_SIZE(128, 128),
+	SET_KMALLOC_SIZE(256, 256),
+	SET_KMALLOC_SIZE(512, 512),
+	SET_KMALLOC_SIZE(1024, 1k),
+	SET_KMALLOC_SIZE(2048, 2k),
+	SET_KMALLOC_SIZE(4096, 4k),
+	SET_KMALLOC_SIZE(8192, 8k),
+	SET_KMALLOC_SIZE(16384, 16k),
+	SET_KMALLOC_SIZE(32768, 32k),
+	SET_KMALLOC_SIZE(65536, 64k),
+	SET_KMALLOC_SIZE(131072, 128k),
+	SET_KMALLOC_SIZE(262144, 256k),
+	SET_KMALLOC_SIZE(524288, 512k),
+	SET_KMALLOC_SIZE(1048576, 1M),
+	SET_KMALLOC_SIZE(2097152, 2M),
+	SET_KMALLOC_SIZE(4194304, 4M),
+	SET_KMALLOC_SIZE(8388608, 8M),
+	SET_KMALLOC_SIZE(16777216, 16M),
+	SET_KMALLOC_SIZE(33554432, 32M),
+	SET_KMALLOC_SIZE(67108864, 64M)
 };
 
 /*
@@ -1161,36 +1191,14 @@ 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);
 }
@@ -1232,11 +1240,10 @@ 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
-- 
2.21.0