Date:	Wed,  7 Sep 2011 09:09:06 -0500
From:	Seth Jennings <sjenning@...ux.vnet.ibm.com>
To:	gregkh@...e.de
Cc:	dan.magenheimer@...cle.com, ngupta@...are.org,
	cascardo@...oscopio.com, devel@...verdev.osuosl.org,
	linux-kernel@...r.kernel.org, rdunlap@...otime.net,
	linux-mm@...ck.org, rcj@...ux.vnet.ibm.com,
	dave@...ux.vnet.ibm.com, brking@...ux.vnet.ibm.com,
	Seth Jennings <sjenning@...ux.vnet.ibm.com>
Subject: [PATCH v2 2/3] staging: zcache: replace xvmalloc with xcfmalloc

This patch replaces xvmalloc with xcfmalloc as the persistent page
allocator for zcache.

Because the API is not the same between xvmalloc and xcfmalloc, the
changes are not a simple find/replace on the function names.

Signed-off-by: Seth Jennings <sjenning@...ux.vnet.ibm.com>
---
 drivers/staging/zcache/zcache-main.c |  130 ++++++++++++++++++++++------------
 1 files changed, 84 insertions(+), 46 deletions(-)

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index a3f5162..b07377b 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -8,7 +8,7 @@
  * and, thus indirectly, for cleancache and frontswap.  Zcache includes two
  * page-accessible memory [1] interfaces, both utilizing lzo1x compression:
  * 1) "compression buddies" ("zbud") is used for ephemeral pages
- * 2) xvmalloc is used for persistent pages.
+ * 2) xcfmalloc is used for persistent pages.
  * Xvmalloc (based on the TLSF allocator) has very low fragmentation
  * so maximizes space efficiency, while zbud allows pairs (and potentially,
  * in the future, more than a pair of) compressed pages to be closely linked
@@ -31,7 +31,7 @@
 #include <linux/math64.h>
 #include "tmem.h"
 
-#include "../zram/xvmalloc.h" /* if built in drivers/staging */
+#include "xcfmalloc.h"
 
 #if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP))
 #error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP"
@@ -60,7 +60,7 @@ MODULE_LICENSE("GPL");
 
 struct zcache_client {
 	struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT];
-	struct xv_pool *xvpool;
+	struct xcf_pool *xcfmpool;
 	bool allocated;
 	atomic_t refcount;
 };
@@ -623,9 +623,8 @@ static int zbud_show_cumul_chunk_counts(char *buf)
 #endif
 
 /**********
- * This "zv" PAM implementation combines the TLSF-based xvMalloc
- * with lzo1x compression to maximize the amount of data that can
- * be packed into a physical page.
+ * This "zv" PAM implementation combines xcfmalloc with lzo1x compression
+ * to maximize the amount of data that can be packed into a physical page.
  *
  * Zv represents a PAM page with the index and object (plus a "size" value
  * necessary for decompression) immediately preceding the compressed data.
@@ -658,71 +657,97 @@ static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5;
 static unsigned long zv_curr_dist_counts[NCHUNKS];
 static unsigned long zv_cumul_dist_counts[NCHUNKS];
 
-static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id,
+static DEFINE_PER_CPU(unsigned char *, zv_cbuf); /* zv create buffer */
+static DEFINE_PER_CPU(unsigned char *, zv_dbuf); /* zv decompress buffer */
+
+static int zv_cpu_notifier(struct notifier_block *nb,
+				unsigned long action, void *pcpu)
+{
+	int cpu = (long)pcpu;
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+		per_cpu(zv_cbuf, cpu) = (void *)__get_free_page(
+			GFP_KERNEL | __GFP_REPEAT);
+		per_cpu(zv_dbuf, cpu) = (void *)__get_free_page(
+			GFP_KERNEL | __GFP_REPEAT);
+		break;
+	case CPU_DEAD:
+	case CPU_UP_CANCELED:
+		free_page((unsigned long)per_cpu(zv_cbuf, cpu));
+		per_cpu(zv_cbuf, cpu) = NULL;
+		free_page((unsigned long)per_cpu(zv_dbuf, cpu));
+		per_cpu(zv_dbuf, cpu) = NULL;
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+
+static void **zv_create(struct xcf_pool *xcfmpool, uint32_t pool_id,
 				struct tmem_oid *oid, uint32_t index,
 				void *cdata, unsigned clen)
 {
-	struct page *page;
-	struct zv_hdr *zv = NULL;
-	uint32_t offset;
-	int alloc_size = clen + sizeof(struct zv_hdr);
-	int chunks = (alloc_size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
-	int ret;
+	struct zv_hdr *zv;
+	u32 size = clen + sizeof(struct zv_hdr);
+	int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
+	void *handle;
 
 	BUG_ON(!irqs_disabled());
 	BUG_ON(chunks >= NCHUNKS);
-	ret = xv_malloc(xvpool, alloc_size,
-			&page, &offset, ZCACHE_GFP_MASK);
-	if (unlikely(ret))
-		goto out;
+
+	handle = xcf_malloc(xcfmpool, size, ZCACHE_GFP_MASK);
+	if (!handle)
+		return NULL;
+
 	zv_curr_dist_counts[chunks]++;
 	zv_cumul_dist_counts[chunks]++;
-	zv = kmap_atomic(page, KM_USER0) + offset;
+
+	zv = (struct zv_hdr *)((char *)cdata - sizeof(*zv));
 	zv->index = index;
 	zv->oid = *oid;
 	zv->pool_id = pool_id;
 	SET_SENTINEL(zv, ZVH);
-	memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen);
-	kunmap_atomic(zv, KM_USER0);
-out:
-	return zv;
+	xcf_write(handle, zv);
+
+	return handle;
 }
 
-static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv)
+static void zv_free(struct xcf_pool *xcfmpool, void *handle)
 {
 	unsigned long flags;
-	struct page *page;
-	uint32_t offset;
-	uint16_t size = xv_get_object_size(zv);
+	u32 size = xcf_get_alloc_size(handle);
 	int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
 
-	ASSERT_SENTINEL(zv, ZVH);
 	BUG_ON(chunks >= NCHUNKS);
 	zv_curr_dist_counts[chunks]--;
-	size -= sizeof(*zv);
-	BUG_ON(size == 0);
-	INVERT_SENTINEL(zv, ZVH);
-	page = virt_to_page(zv);
-	offset = (unsigned long)zv & ~PAGE_MASK;
+
 	local_irq_save(flags);
-	xv_free(xvpool, page, offset);
+	xcf_free(xcfmpool, handle);
 	local_irq_restore(flags);
 }
 
-static void zv_decompress(struct page *page, struct zv_hdr *zv)
+static void zv_decompress(struct page *page, void *handle)
 {
 	size_t clen = PAGE_SIZE;
 	char *to_va;
 	unsigned size;
 	int ret;
+	struct zv_hdr *zv;
 
-	ASSERT_SENTINEL(zv, ZVH);
-	size = xv_get_object_size(zv) - sizeof(*zv);
+	size = xcf_get_alloc_size(handle) - sizeof(*zv);
 	BUG_ON(size == 0);
+	zv = (struct zv_hdr *)(get_cpu_var(zv_dbuf));
+	xcf_read(handle, zv);
+	ASSERT_SENTINEL(zv, ZVH);
 	to_va = kmap_atomic(page, KM_USER0);
 	ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv),
 					size, to_va, &clen);
 	kunmap_atomic(to_va, KM_USER0);
+	put_cpu_var(zv_dbuf);
 	BUG_ON(ret != LZO_E_OK);
 	BUG_ON(clen != PAGE_SIZE);
 }
@@ -949,8 +974,9 @@ int zcache_new_client(uint16_t cli_id)
 		goto out;
 	cli->allocated = 1;
 #ifdef CONFIG_FRONTSWAP
-	cli->xvpool = xv_create_pool();
-	if (cli->xvpool == NULL)
+	cli->xcfmpool =
+		xcf_create_pool(ZCACHE_GFP_MASK);
+	if (cli->xcfmpool == NULL)
 		goto out;
 #endif
 	ret = 0;
@@ -1154,7 +1180,7 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
 				struct tmem_pool *pool, struct tmem_oid *oid,
 				 uint32_t index)
 {
-	void *pampd = NULL, *cdata;
+	void *pampd = NULL, *cdata = NULL;
 	size_t clen;
 	int ret;
 	unsigned long count;
@@ -1186,26 +1212,30 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
 		if (curr_pers_pampd_count >
 		    (zv_page_count_policy_percent * totalram_pages) / 100)
 			goto out;
+		cdata = get_cpu_var(zv_cbuf) + sizeof(struct zv_hdr);
 		ret = zcache_compress(page, &cdata, &clen);
 		if (ret == 0)
 			goto out;
 		/* reject if compression is too poor */
 		if (clen > zv_max_zsize) {
 			zcache_compress_poor++;
+			put_cpu_var(zv_cbuf);
 			goto out;
 		}
 		/* reject if mean compression is too poor */
 		if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
-			total_zsize = xv_get_total_size_bytes(cli->xvpool);
+			total_zsize = xcf_get_total_size_bytes(cli->xcfmpool);
 			zv_mean_zsize = div_u64(total_zsize,
 						curr_pers_pampd_count);
 			if (zv_mean_zsize > zv_max_mean_zsize) {
 				zcache_mean_compress_poor++;
+				put_cpu_var(zv_cbuf);
 				goto out;
 			}
 		}
-		pampd = (void *)zv_create(cli->xvpool, pool->pool_id,
+		pampd = (void *)zv_create(cli->xcfmpool, pool->pool_id,
 						oid, index, cdata, clen);
+		put_cpu_var(zv_cbuf);
 		if (pampd == NULL)
 			goto out;
 		count = atomic_inc_return(&zcache_curr_pers_pampd_count);
@@ -1262,7 +1292,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
 		atomic_dec(&zcache_curr_eph_pampd_count);
 		BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0);
 	} else {
-		zv_free(cli->xvpool, (struct zv_hdr *)pampd);
+		zv_free(cli->xcfmpool, pampd);
 		atomic_dec(&zcache_curr_pers_pampd_count);
 		BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0);
 	}
@@ -1309,11 +1339,16 @@ static DEFINE_PER_CPU(unsigned char *, zcache_dstmem);
 static int zcache_compress(struct page *from, void **out_va, size_t *out_len)
 {
 	int ret = 0;
-	unsigned char *dmem = __get_cpu_var(zcache_dstmem);
+	unsigned char *dmem;
 	unsigned char *wmem = __get_cpu_var(zcache_workmem);
 	char *from_va;
 
 	BUG_ON(!irqs_disabled());
+	if (out_va && *out_va)
+		dmem = *out_va;
+	else
+		dmem = __get_cpu_var(zcache_dstmem);
+
 	if (unlikely(dmem == NULL || wmem == NULL))
 		goto out;  /* no buffer, so can't compress */
 	from_va = kmap_atomic(from, KM_USER0);
@@ -1331,7 +1366,7 @@ out:
 static int zcache_cpu_notifier(struct notifier_block *nb,
 				unsigned long action, void *pcpu)
 {
-	int cpu = (long)pcpu;
+	int ret, cpu = (long)pcpu;
 	struct zcache_preload *kp;
 
 	switch (action) {
@@ -1363,7 +1398,10 @@ static int zcache_cpu_notifier(struct notifier_block *nb,
 	default:
 		break;
 	}
-	return NOTIFY_OK;
+
+	ret = zv_cpu_notifier(nb, action, pcpu);
+
+	return ret;
 }
 
 static struct notifier_block zcache_cpu_notifier_block = {
@@ -1991,7 +2029,7 @@ static int __init zcache_init(void)
 
 		old_ops = zcache_frontswap_register_ops();
 		pr_info("zcache: frontswap enabled using kernel "
-			"transcendent memory and xvmalloc\n");
+			"transcendent memory and xcfmalloc\n");
 		if (old_ops.init != NULL)
 			pr_warning("ktmem: frontswap_ops overridden");
 	}
-- 
1.7.4.1

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