Commit 42614b05 authored May 27, 2014 by Eric Dumazet Committed by Herbert Xu Jun 20, 2014

crypto: lzo - try kmalloc() before vmalloc()

zswap allocates one LZO context per online cpu.

Using vmalloc() for small (16KB) memory areas has drawback of slowing
down /proc/vmallocinfo and /proc/meminfo reads, TLB pressure and poor
NUMA locality, as default NUMA policy at boot time is to interleave
pages :

edumazet:~# grep lzo /proc/vmallocinfo | head -4
0xffffc90006062000-0xffffc90006067000 20480 lzo_init+0x1b/0x30 pages=4 vmalloc N0=2 N1=2
0xffffc90006067000-0xffffc9000606c000 20480 lzo_init+0x1b/0x30 pages=4 vmalloc N0=2 N1=2
0xffffc9000606c000-0xffffc90006071000 20480 lzo_init+0x1b/0x30 pages=4 vmalloc N0=2 N1=2
0xffffc90006071000-0xffffc90006076000 20480 lzo_init+0x1b/0x30 pages=4 vmalloc N0=2 N1=2

This patch tries a regular kmalloc() and fallback to vmalloc in case
memory is too fragmented.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

parent d656c180

crypto/lzo.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <linux/module.h>
		#include <linux/crypto.h>
		#include <linux/vmalloc.h>
		#include <linux/mm.h>
		#include <linux/lzo.h>

		struct lzo_ctx {
		@@ -30,6 +31,9 @@ static int lzo_init(struct crypto_tfm *tfm)
		{
		struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);

		ctx->lzo_comp_mem = kmalloc(LZO1X_MEM_COMPRESS,
		GFP_KERNEL \| __GFP_NOWARN \| __GFP_REPEAT);
		if (!ctx->lzo_comp_mem)
		ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
		if (!ctx->lzo_comp_mem)
		return -ENOMEM;
		@@ -41,7 +45,10 @@ static void lzo_exit(struct crypto_tfm *tfm)
		{
		struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);

		if (is_vmalloc_addr(ctx->lzo_comp_mem))
		vfree(ctx->lzo_comp_mem);
		else
		kfree(ctx->lzo_comp_mem);
		}

		static int lzo_compress(struct crypto_tfm tfm, const u8 src,