From 22a83f172618ec70925370d5d4efec606975c278 Mon Sep 17 00:00:00 2001
From: Alessandro Rubini <rubini@gnudd.com>
Date: Tue, 31 Jan 2012 18:04:46 +0100
Subject: [PATCH] zio-buf-kmalloc: use kmem_cache for block structures
This saves another 0.1 usec for each block lifetime.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>
---
buffers/zio-buf-kmalloc.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/buffers/zio-buf-kmalloc.c b/buffers/zio-buf-kmalloc.c
index 4cdc724..8b7009a 100644
--- a/buffers/zio-buf-kmalloc.c
+++ b/buffers/zio-buf-kmalloc.c
@@ -31,6 +31,9 @@ struct zbk_instance {
};
#define to_zbki(bi) container_of(bi, struct zbk_instance, bi)
+static struct kmem_cache *zbk_slab;
+
+
/* The list in the structure above collects a bunch of these */
struct zbk_item {
struct zio_block block;
@@ -66,10 +69,11 @@ static struct zio_block *zbk_alloc_block(struct zio_bi *bi,
pr_debug("%s:%d\n", __func__, __LINE__);
/* alloc item and data. Control remains null at this point */
- item = kzalloc(sizeof(*item), gfp);
+ item = kmem_cache_alloc(zbk_slab, gfp);
data = kmalloc(datalen, gfp);
if (!item || !data)
goto out_free;
+ memset(item, 0, sizeof(*item));
item->block.data = data;
item->block.datalen = datalen;
item->instance = zbki;
@@ -80,7 +84,7 @@ static struct zio_block *zbk_alloc_block(struct zio_bi *bi,
out_free:
kfree(data);
- kfree(item);
+ kmem_cache_free(zbk_slab, item);
return ERR_PTR(-ENOMEM);
}
@@ -96,7 +100,7 @@ static void zbk_free_block(struct zio_bi *bi, struct zio_block *block)
zbki = item->instance;
kfree(block->data);
zio_free_control(zio_get_ctrl(block));
- kfree(item);
+ kmem_cache_free(zbk_slab, item);
}
/* When write() stores the first block, we try pushing it */
@@ -228,7 +232,7 @@ static void zbk_destroy(struct zio_bi *bi)
item = list_entry(pos, struct zbk_item, list);
zbk_free_block(&zbki->bi, &item->block);
}
- kfree(zbki);
+ kmem_cache_free(zbk_slab, zbki);
}
static const struct zio_buffer_operations zbk_buffer_ops = {
@@ -265,12 +269,22 @@ static struct zio_buffer_type zbk_buffer = {
static int __init zbk_init(void)
{
- return zio_register_buf(&zbk_buffer, "kmalloc");
+ int ret;
+
+ zbk_slab = KMEM_CACHE(zbk_item, 0);
+ if (!zbk_slab)
+ return -ENOMEM;
+ ret = zio_register_buf(&zbk_buffer, "kmalloc");
+ if (ret < 0)
+ kmem_cache_destroy(zbk_slab);
+ return ret;
+
}
static void __exit zbk_exit(void)
{
zio_unregister_buf(&zbk_buffer);
+ kmem_cache_destroy(zbk_slab);
}
/* This is the default buffer, and is part of zio-core: no module init/exit */
--
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