ramzswap driver creates virtual block devices which
can be used (only) as swap disks. Pages swapped to these
disks are compressed and stored in memory itself.
Project home: http://code.google.com/p/compcache/
These patches apply to linux-next.
Signed-off-by: Nitin Gupta <[email protected]>
Nitin Gupta (3):
use lock for 64-bit stats
flush block device before reset
set block size to PAGE_SIZE and some cleanups
drivers/staging/ramzswap/ramzswap_drv.c | 144 ++++++++++++++++------------
drivers/staging/ramzswap/ramzswap_drv.h | 61 ++++++++++--
drivers/staging/ramzswap/ramzswap_ioctl.h | 3 +-
drivers/staging/ramzswap/xvmalloc.c | 2 +-
drivers/staging/ramzswap/xvmalloc.h | 2 +-
drivers/staging/ramzswap/xvmalloc_int.h | 2 +-
6 files changed, 137 insertions(+), 77 deletions(-)
64-bit stats corruption was observed when ramzswap was
used on SMP systems. To prevent this, use separate spinlock
to protect these stats.
Eventually, these will be converted to per-cpu counters
if this driver finds use on large scale systems and this
locking is found to affect scalability.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/ramzswap_drv.c | 58 +++++++++++++++--------------
drivers/staging/ramzswap/ramzswap_drv.h | 59 ++++++++++++++++++++++++-----
drivers/staging/ramzswap/ramzswap_ioctl.h | 1 +
3 files changed, 80 insertions(+), 38 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index baf7572..0a376c2 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -24,7 +24,6 @@
#include <linux/genhd.h>
#include <linux/highmem.h>
#include <linux/lzo.h>
-#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/swap.h>
#include <linux/swapops.h>
@@ -239,7 +238,8 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
mem_used = xv_get_total_size_bytes(rzs->mem_pool)
+ (rs->pages_expand << PAGE_SHIFT);
- succ_writes = rs->num_writes - rs->failed_writes;
+ succ_writes = stat64_read(rzs, &rs->num_writes) -
+ stat64_read(rzs, &rs->failed_writes);
if (succ_writes && rs->pages_stored) {
good_compress_perc = rs->good_compress * 100
@@ -248,11 +248,12 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
/ rs->pages_stored;
}
- s->num_reads = rs->num_reads;
- s->num_writes = rs->num_writes;
- s->failed_reads = rs->failed_reads;
- s->failed_writes = rs->failed_writes;
- s->invalid_io = rs->invalid_io;
+ s->num_reads = stat64_read(rzs, &rs->num_reads);
+ s->num_writes = stat64_read(rzs, &rs->num_writes);
+ s->failed_reads = stat64_read(rzs, &rs->failed_reads);
+ s->failed_writes = stat64_read(rzs, &rs->failed_writes);
+ s->invalid_io = stat64_read(rzs, &rs->invalid_io);
+ s->notify_free = stat64_read(rzs, &rs->notify_free);
s->pages_zero = rs->pages_zero;
s->good_compress_pct = good_compress_perc;
@@ -264,8 +265,8 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
s->compr_data_size = rs->compr_size;
s->mem_used_total = mem_used;
- s->bdev_num_reads = rs->bdev_num_reads;
- s->bdev_num_writes = rs->bdev_num_writes;
+ s->bdev_num_reads = stat64_read(rzs, &rs->bdev_num_reads);
+ s->bdev_num_writes = stat64_read(rzs, &rs->bdev_num_writes);
}
#endif /* CONFIG_RAMZSWAP_STATS */
}
@@ -594,7 +595,7 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
if (unlikely(!page)) {
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
rzs_clear_flag(rzs, index, RZS_ZERO);
- stat_dec(rzs->stats.pages_zero);
+ stat_dec(&rzs->stats.pages_zero);
}
return;
}
@@ -603,7 +604,7 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
clen = PAGE_SIZE;
__free_page(page);
rzs_clear_flag(rzs, index, RZS_UNCOMPRESSED);
- stat_dec(rzs->stats.pages_expand);
+ stat_dec(&rzs->stats.pages_expand);
goto out;
}
@@ -613,11 +614,11 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
xv_free(rzs->mem_pool, page, offset);
if (clen <= PAGE_SIZE / 2)
- stat_dec(rzs->stats.good_compress);
+ stat_dec(&rzs->stats.good_compress);
out:
rzs->stats.compr_size -= clen;
- stat_dec(rzs->stats.pages_stored);
+ stat_dec(&rzs->stats.pages_stored);
rzs->table[index].page = NULL;
rzs->table[index].offset = 0;
@@ -679,8 +680,8 @@ static int handle_ramzswap_fault(struct ramzswap *rzs, struct bio *bio)
*/
if (rzs->backing_swap) {
u32 pagenum;
- stat_dec(rzs->stats.num_reads);
- stat_inc(rzs->stats.bdev_num_reads);
+ stat64_dec(rzs, &rzs->stats.num_reads);
+ stat64_inc(rzs, &rzs->stats.bdev_num_reads);
bio->bi_bdev = rzs->backing_swap;
/*
@@ -718,7 +719,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
struct zobj_header *zheader;
unsigned char *user_mem, *cmem;
- stat_inc(rzs->stats.num_reads);
+ stat64_inc(rzs, &rzs->stats.num_reads);
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
@@ -752,7 +753,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
if (unlikely(ret != LZO_E_OK)) {
pr_err("Decompression failed! err=%d, page=%u\n",
ret, index);
- stat_inc(rzs->stats.failed_reads);
+ stat64_inc(rzs, &rzs->stats.failed_reads);
goto out;
}
@@ -776,7 +777,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
struct page *page, *page_store;
unsigned char *user_mem, *cmem, *src;
- stat_inc(rzs->stats.num_writes);
+ stat64_inc(rzs, &rzs->stats.num_writes);
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
@@ -796,7 +797,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
* Simply clear zero page flag.
*/
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
- stat_dec(rzs->stats.pages_zero);
+ stat_dec(&rzs->stats.pages_zero);
rzs_clear_flag(rzs, index, RZS_ZERO);
}
@@ -806,7 +807,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
if (page_zero_filled(user_mem)) {
kunmap_atomic(user_mem, KM_USER0);
mutex_unlock(&rzs->lock);
- stat_inc(rzs->stats.pages_zero);
+ stat_inc(&rzs->stats.pages_zero);
rzs_set_flag(rzs, index, RZS_ZERO);
set_bit(BIO_UPTODATE, &bio->bi_flags);
@@ -830,7 +831,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
if (unlikely(ret != LZO_E_OK)) {
mutex_unlock(&rzs->lock);
pr_err("Compression failed! err=%d\n", ret);
- stat_inc(rzs->stats.failed_writes);
+ stat64_inc(rzs, &rzs->stats.failed_writes);
goto out;
}
@@ -853,13 +854,13 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
mutex_unlock(&rzs->lock);
pr_info("Error allocating memory for incompressible "
"page: %u\n", index);
- stat_inc(rzs->stats.failed_writes);
+ stat64_inc(rzs, &rzs->stats.failed_writes);
goto out;
}
offset = 0;
rzs_set_flag(rzs, index, RZS_UNCOMPRESSED);
- stat_inc(rzs->stats.pages_expand);
+ stat_inc(&rzs->stats.pages_expand);
rzs->table[index].page = page_store;
src = kmap_atomic(page, KM_USER0);
goto memstore;
@@ -871,7 +872,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
mutex_unlock(&rzs->lock);
pr_info("Error allocating memory for compressed "
"page: %u, size=%zu\n", index, clen);
- stat_inc(rzs->stats.failed_writes);
+ stat64_inc(rzs, &rzs->stats.failed_writes);
if (rzs->backing_swap)
fwd_write_request = 1;
goto out;
@@ -900,9 +901,9 @@ memstore:
/* Update stats */
rzs->stats.compr_size += clen;
- stat_inc(rzs->stats.pages_stored);
+ stat_inc(&rzs->stats.pages_stored);
if (clen <= PAGE_SIZE / 2)
- stat_inc(rzs->stats.good_compress);
+ stat_inc(&rzs->stats.good_compress);
mutex_unlock(&rzs->lock);
@@ -912,7 +913,7 @@ memstore:
out:
if (fwd_write_request) {
- stat_inc(rzs->stats.bdev_num_writes);
+ stat64_inc(rzs, &rzs->stats.bdev_num_writes);
bio->bi_bdev = rzs->backing_swap;
#if 0
/*
@@ -974,7 +975,7 @@ static int ramzswap_make_request(struct request_queue *queue, struct bio *bio)
}
if (!valid_swap_request(rzs, bio)) {
- stat_inc(rzs->stats.invalid_io);
+ stat64_inc(rzs, &rzs->stats.invalid_io);
bio_io_error(bio);
return 0;
}
@@ -1295,6 +1296,7 @@ static struct block_device_operations ramzswap_devops = {
static int create_device(struct ramzswap *rzs, int device_id)
{
mutex_init(&rzs->lock);
+ spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
rzs->queue = blk_alloc_queue(GFP_KERNEL);
diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h
index 7ba98bf..3831d93 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.h
+++ b/drivers/staging/ramzswap/ramzswap_drv.h
@@ -15,6 +15,9 @@
#ifndef _RAMZSWAP_DRV_H_
#define _RAMZSWAP_DRV_H_
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+
#include "ramzswap_ioctl.h"
#include "xvmalloc.h"
@@ -71,15 +74,6 @@ static const unsigned max_zpage_size_nobdev = PAGE_SIZE / 4 * 3;
#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT)
-/* Debugging and Stats */
-#if defined(CONFIG_RAMZSWAP_STATS)
-#define stat_inc(stat) ((stat)++)
-#define stat_dec(stat) ((stat)--)
-#else
-#define stat_inc(x)
-#define stat_dec(x)
-#endif
-
/* Flags for ramzswap pages (table[page_no].flags) */
enum rzs_pageflags {
/* Page is stored uncompressed */
@@ -124,6 +118,7 @@ struct ramzswap_stats {
u64 failed_reads; /* should NEVER! happen */
u64 failed_writes; /* can happen when memory is too low */
u64 invalid_io; /* non-swap I/O requests */
+ u64 notify_free; /* no. of swap slot free notifications */
u32 pages_zero; /* no. of zero filled pages */
u32 pages_stored; /* no. of pages currently stored */
u32 good_compress; /* % of pages with compression ratio<=50% */
@@ -138,6 +133,7 @@ struct ramzswap {
void *compress_workmem;
void *compress_buffer;
struct table *table;
+ spinlock_t stat64_lock; /* protect 64-bit stats */
struct mutex lock;
struct request_queue *queue;
struct gendisk *disk;
@@ -167,5 +163,48 @@ struct ramzswap {
/*-- */
-#endif
+/* Debugging and Stats */
+#if defined(CONFIG_RAMZSWAP_STATS)
+static void stat_inc(u32 *v)
+{
+ *v = *v + 1;
+}
+
+static void stat_dec(u32 *v)
+{
+ *v = *v - 1;
+}
+
+static void stat64_inc(struct ramzswap *rzs, u64 *v)
+{
+ spin_lock(&rzs->stat64_lock);
+ *v = *v + 1;
+ spin_unlock(&rzs->stat64_lock);
+}
+
+static void stat64_dec(struct ramzswap *rzs, u64 *v)
+{
+ spin_lock(&rzs->stat64_lock);
+ *v = *v - 1;
+ spin_unlock(&rzs->stat64_lock);
+}
+
+static u64 stat64_read(struct ramzswap *rzs, u64 *v)
+{
+ u64 val;
+
+ spin_lock(&rzs->stat64_lock);
+ val = *v;
+ spin_unlock(&rzs->stat64_lock);
+
+ return val;
+}
+#else
+#define stat_inc(v)
+#define stat_dec(v)
+#define stat64_inc(r, v)
+#define stat64_dec(r, v)
+#define stat64_read(r, v)
+#endif /* CONFIG_RAMZSWAP_STATS */
+#endif
diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h
index 1bc54e2..1edaeba 100644
--- a/drivers/staging/ramzswap/ramzswap_ioctl.h
+++ b/drivers/staging/ramzswap/ramzswap_ioctl.h
@@ -27,6 +27,7 @@ struct ramzswap_ioctl_stats {
u64 failed_reads; /* should NEVER! happen */
u64 failed_writes; /* can happen when memory is too low */
u64 invalid_io; /* non-swap I/O requests */
+ u64 notify_free; /* no. of swap slot free notifications */
u32 pages_zero; /* no. of zero filled pages */
u32 good_compress_pct; /* no. of pages with compression ratio<=50% */
u32 pages_expand_pct; /* no. of incompressible pages */
--
1.6.2.5
Make sure we flush block device before freeing all metadata
during reset ioctl.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/ramzswap_drv.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 0a376c2..64f49c9 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1000,6 +1000,9 @@ static void reset_device(struct ramzswap *rzs)
unsigned entries_per_page;
unsigned long num_table_pages, entry = 0;
+ /* Do not accept any new I/O request */
+ rzs->init_done = 0;
+
if (rzs->backing_swap && !rzs->num_extents)
is_backing_blkdev = 1;
@@ -1073,9 +1076,6 @@ static void reset_device(struct ramzswap *rzs)
rzs->disksize = 0;
rzs->memlimit = 0;
-
- /* Back to uninitialized state */
- rzs->init_done = 0;
}
static int ramzswap_ioctl_init_device(struct ramzswap *rzs)
@@ -1276,6 +1276,11 @@ static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
ret = -EBUSY;
goto out;
}
+
+ /* Make sure all pending I/O is finished */
+ if (bdev)
+ fsync_bdev(bdev);
+
ret = ramzswap_ioctl_reset_device(rzs);
break;
--
1.6.2.5
ramzswap block size needs to be set to PAGE_SIZE
to avoid receiving any unaligned block I/O (happens
during swapon time). These unaligned access produce
unncessary I/O errors, scaring users.
Also included some minor cleanups.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/ramzswap_drv.c | 77 +++++++++++++++++------------
drivers/staging/ramzswap/ramzswap_drv.h | 2 +-
drivers/staging/ramzswap/ramzswap_ioctl.h | 2 +-
drivers/staging/ramzswap/xvmalloc.c | 2 +-
drivers/staging/ramzswap/xvmalloc.h | 2 +-
drivers/staging/ramzswap/xvmalloc_int.h | 2 +-
6 files changed, 50 insertions(+), 37 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 64f49c9..7f47373 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
@@ -220,7 +220,7 @@ out:
return ret;
}
-void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
+static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
struct ramzswap_ioctl_stats *s)
{
strncpy(s->backing_swap_name, rzs->backing_swap_name,
@@ -502,6 +502,10 @@ static int setup_backing_swap(struct ramzswap *rzs)
goto bad_param;
}
disksize = i_size_read(inode);
+ if (!disksize) {
+ pr_err("Error reading backing swap size.\n");
+ goto bad_param;
+ }
} else if (S_ISREG(inode->i_mode)) {
bdev = inode->i_sb->s_bdev;
if (IS_SWAPFILE(inode)) {
@@ -519,7 +523,6 @@ static int setup_backing_swap(struct ramzswap *rzs)
rzs->swap_file = swap_file;
rzs->backing_swap = bdev;
rzs->disksize = disksize;
- BUG_ON(!rzs->disksize);
return 0;
@@ -537,7 +540,7 @@ out:
* Map logical page number 'pagenum' to physical page number
* on backing swap device. For block device, this is a nop.
*/
-u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
+static u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
{
u32 skip_pages, entries_per_page;
size_t delta, se_offset, skipped;
@@ -593,6 +596,10 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
u32 offset = rzs->table[index].offset;
if (unlikely(!page)) {
+ /*
+ * No memory is allocated for zero filled pages.
+ * Simply clear zero page flag.
+ */
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
rzs_clear_flag(rzs, index, RZS_ZERO);
stat_dec(&rzs->stats.pages_zero);
@@ -664,7 +671,6 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
return 0;
}
-
/*
* Called when request page is not present in ramzswap.
* Its either in backing swap device (if present) or
@@ -782,24 +788,15 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
- src = rzs->compress_buffer;
-
/*
* System swaps to same sector again when the stored page
* is no longer referenced by any process. So, its now safe
* to free the memory that was allocated for this page.
*/
- if (rzs->table[index].page)
+ if (rzs->table[index].page || rzs_test_flag(rzs, index, RZS_ZERO))
ramzswap_free_page(rzs, index);
- /*
- * No memory is allocated for zero filled pages.
- * Simply clear zero page flag.
- */
- if (rzs_test_flag(rzs, index, RZS_ZERO)) {
- stat_dec(&rzs->stats.pages_zero);
- rzs_clear_flag(rzs, index, RZS_ZERO);
- }
+ src = rzs->compress_buffer;
mutex_lock(&rzs->lock);
@@ -941,7 +938,6 @@ out:
return 0;
}
-
/*
* Check if request is within bounds and page aligned.
*/
@@ -1069,6 +1065,7 @@ static void reset_device(struct ramzswap *rzs)
bd_release(rzs->backing_swap);
filp_close(rzs->swap_file, NULL);
rzs->backing_swap = NULL;
+ memset(rzs->backing_swap_name, 0, MAX_SWAP_NAME_LEN);
}
/* Reset stats */
@@ -1300,6 +1297,7 @@ static struct block_device_operations ramzswap_devops = {
static int create_device(struct ramzswap *rzs, int device_id)
{
+ int ret = 0;
mutex_init(&rzs->lock);
spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
@@ -1308,7 +1306,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
if (!rzs->queue) {
pr_err("Error allocating disk queue for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
blk_queue_make_request(rzs->queue, ramzswap_make_request);
@@ -1320,7 +1319,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
blk_cleanup_queue(rzs->queue);
pr_warning("Error allocating disk structure for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
rzs->disk->major = ramzswap_major;
@@ -1335,10 +1335,16 @@ static int create_device(struct ramzswap *rzs, int device_id)
* or set equal to backing swap device (if provided)
*/
set_capacity(rzs->disk, 0);
+
+ blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE);
+ blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE);
+
add_disk(rzs->disk);
rzs->init_done = 0;
- return 1;
+
+out:
+ return ret;
}
static void destroy_device(struct ramzswap *rzs)
@@ -1354,18 +1360,20 @@ static void destroy_device(struct ramzswap *rzs)
static int __init ramzswap_init(void)
{
- int i, ret;
+ int ret, dev_id;
if (num_devices > max_num_devices) {
pr_warning("Invalid value for num_devices: %u\n",
num_devices);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
ramzswap_major = register_blkdev(0, "ramzswap");
if (ramzswap_major <= 0) {
pr_warning("Unable to get major number\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto out;
}
if (!num_devices) {
@@ -1376,21 +1384,26 @@ static int __init ramzswap_init(void)
/* Allocate the device array and initialize each one */
pr_info("Creating %u devices ...\n", num_devices);
devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
- if (!devices)
- goto out;
+ if (!devices) {
+ ret = -ENOMEM;
+ goto unregister;
+ }
- for (i = 0; i < num_devices; i++)
- if (!create_device(&devices[i], i)) {
- ret = i;
+ for (dev_id = 0; dev_id < num_devices; dev_id++) {
+ if (create_device(&devices[dev_id], dev_id)) {
+ ret = -ENOMEM;
goto free_devices;
}
+ }
+
return 0;
+
free_devices:
- for (i = 0; i < ret; i++)
- destroy_device(&devices[i]);
-out:
- ret = -ENOMEM;
+ while (dev_id)
+ destroy_device(&devices[--dev_id]);
+unregister:
unregister_blkdev(ramzswap_major, "ramzswap");
+out:
return ret;
}
diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h
index 3831d93..e5ffdce 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.h
+++ b/drivers/staging/ramzswap/ramzswap_drv.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h
index 1edaeba..d26076d 100644
--- a/drivers/staging/ramzswap/ramzswap_ioctl.h
+++ b/drivers/staging/ramzswap/ramzswap_ioctl.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.c b/drivers/staging/ramzswap/xvmalloc.c
index dabd266..3fdbb8a 100644
--- a/drivers/staging/ramzswap/xvmalloc.c
+++ b/drivers/staging/ramzswap/xvmalloc.c
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.h b/drivers/staging/ramzswap/xvmalloc.h
index 010c6fe..5b1a81a 100644
--- a/drivers/staging/ramzswap/xvmalloc.h
+++ b/drivers/staging/ramzswap/xvmalloc.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc_int.h b/drivers/staging/ramzswap/xvmalloc_int.h
index 263c72d..e23ed5c 100644
--- a/drivers/staging/ramzswap/xvmalloc_int.h
+++ b/drivers/staging/ramzswap/xvmalloc_int.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
--
1.6.2.5
Nitin Gupta wrote:
> +static void stat_dec(u32 *v)
> +{
> + *v = *v - 1;
> +}
> +
> +static void stat64_inc(struct ramzswap *rzs, u64 *v)
> +{
> + spin_lock(&rzs->stat64_lock);
> + *v = *v + 1;
> + spin_unlock(&rzs->stat64_lock);
> +}
> +
> +static void stat64_dec(struct ramzswap *rzs, u64 *v)
> +{
> + spin_lock(&rzs->stat64_lock);
> + *v = *v - 1;
> + spin_unlock(&rzs->stat64_lock);
> +}
> +
> +static u64 stat64_read(struct ramzswap *rzs, u64 *v)
> +{
> + u64 val;
> +
> + spin_lock(&rzs->stat64_lock);
> + val = *v;
> + spin_unlock(&rzs->stat64_lock);
> +
> + return val;
> +}
> +#else
> +#define stat_inc(v)
> +#define stat_dec(v)
> +#define stat64_inc(r, v)
> +#define stat64_dec(r, v)
> +#define stat64_read(r, v)
> +#endif /* CONFIG_RAMZSWAP_STATS */
I think I complained about this before: the names are too generic and
could collide with core kernel code. I think they ought to be called
ramzsawp_stat*().
Pekka
On 01/27/2010 08:40 PM, Pekka Enberg wrote:
> Nitin Gupta wrote:
>> +static void stat_dec(u32 *v)
>> +{
>> + *v = *v - 1;
>> +}
>> +
>> +static void stat64_inc(struct ramzswap *rzs, u64 *v)
>> +{
>> + spin_lock(&rzs->stat64_lock);
>> + *v = *v + 1;
>> + spin_unlock(&rzs->stat64_lock);
>> +}
>> +
>> +static void stat64_dec(struct ramzswap *rzs, u64 *v)
>> +{
>> + spin_lock(&rzs->stat64_lock);
>> + *v = *v - 1;
>> + spin_unlock(&rzs->stat64_lock);
>> +}
>> +
>> +static u64 stat64_read(struct ramzswap *rzs, u64 *v)
>> +{
>> + u64 val;
>> +
>> + spin_lock(&rzs->stat64_lock);
>> + val = *v;
>> + spin_unlock(&rzs->stat64_lock);
>> +
>> + return val;
>> +}
>> +#else
>> +#define stat_inc(v)
>> +#define stat_dec(v)
>> +#define stat64_inc(r, v)
>> +#define stat64_dec(r, v)
>> +#define stat64_read(r, v)
>> +#endif /* CONFIG_RAMZSWAP_STATS */
>
> I think I complained about this before: the names are too generic and
> could collide with core kernel code. I think they ought to be called
> ramzsawp_stat*().
>
I somehow missed this point. I will rename these to rzs_stat*()
('rzs_' prefix is used for other one-liner functions too).
Thanks,
Nitin
64-bit stats corruption was observed when ramzswap was
used on SMP systems. To prevent this, use separate spinlock
to protect these stats.
Also, replace stat_*() with rzs_stat*() to avoid possible
conflict with core kernel code.
Eventually, these will be converted to per-cpu counters
if this driver finds use on large scale systems and this
locking is found to affect scalability.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/ramzswap_drv.c | 58 +++++++++++++++--------------
drivers/staging/ramzswap/ramzswap_drv.h | 59 ++++++++++++++++++++++++-----
drivers/staging/ramzswap/ramzswap_ioctl.h | 1 +
3 files changed, 80 insertions(+), 38 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index baf7572..05273c0 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -24,7 +24,6 @@
#include <linux/genhd.h>
#include <linux/highmem.h>
#include <linux/lzo.h>
-#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/swap.h>
#include <linux/swapops.h>
@@ -239,7 +238,8 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
mem_used = xv_get_total_size_bytes(rzs->mem_pool)
+ (rs->pages_expand << PAGE_SHIFT);
- succ_writes = rs->num_writes - rs->failed_writes;
+ succ_writes = rzs_stat64_read(rzs, &rs->num_writes) -
+ rzs_stat64_read(rzs, &rs->failed_writes);
if (succ_writes && rs->pages_stored) {
good_compress_perc = rs->good_compress * 100
@@ -248,11 +248,12 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
/ rs->pages_stored;
}
- s->num_reads = rs->num_reads;
- s->num_writes = rs->num_writes;
- s->failed_reads = rs->failed_reads;
- s->failed_writes = rs->failed_writes;
- s->invalid_io = rs->invalid_io;
+ s->num_reads = rzs_stat64_read(rzs, &rs->num_reads);
+ s->num_writes = rzs_stat64_read(rzs, &rs->num_writes);
+ s->failed_reads = rzs_stat64_read(rzs, &rs->failed_reads);
+ s->failed_writes = rzs_stat64_read(rzs, &rs->failed_writes);
+ s->invalid_io = rzs_stat64_read(rzs, &rs->invalid_io);
+ s->notify_free = rzs_stat64_read(rzs, &rs->notify_free);
s->pages_zero = rs->pages_zero;
s->good_compress_pct = good_compress_perc;
@@ -264,8 +265,8 @@ void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
s->compr_data_size = rs->compr_size;
s->mem_used_total = mem_used;
- s->bdev_num_reads = rs->bdev_num_reads;
- s->bdev_num_writes = rs->bdev_num_writes;
+ s->bdev_num_reads = rzs_stat64_read(rzs, &rs->bdev_num_reads);
+ s->bdev_num_writes = rzs_stat64_read(rzs, &rs->bdev_num_writes);
}
#endif /* CONFIG_RAMZSWAP_STATS */
}
@@ -594,7 +595,7 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
if (unlikely(!page)) {
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
rzs_clear_flag(rzs, index, RZS_ZERO);
- stat_dec(rzs->stats.pages_zero);
+ rzs_stat_dec(&rzs->stats.pages_zero);
}
return;
}
@@ -603,7 +604,7 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
clen = PAGE_SIZE;
__free_page(page);
rzs_clear_flag(rzs, index, RZS_UNCOMPRESSED);
- stat_dec(rzs->stats.pages_expand);
+ rzs_stat_dec(&rzs->stats.pages_expand);
goto out;
}
@@ -613,11 +614,11 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
xv_free(rzs->mem_pool, page, offset);
if (clen <= PAGE_SIZE / 2)
- stat_dec(rzs->stats.good_compress);
+ rzs_stat_dec(&rzs->stats.good_compress);
out:
rzs->stats.compr_size -= clen;
- stat_dec(rzs->stats.pages_stored);
+ rzs_stat_dec(&rzs->stats.pages_stored);
rzs->table[index].page = NULL;
rzs->table[index].offset = 0;
@@ -679,8 +680,8 @@ static int handle_ramzswap_fault(struct ramzswap *rzs, struct bio *bio)
*/
if (rzs->backing_swap) {
u32 pagenum;
- stat_dec(rzs->stats.num_reads);
- stat_inc(rzs->stats.bdev_num_reads);
+ rzs_stat64_dec(rzs, &rzs->stats.num_reads);
+ rzs_stat64_inc(rzs, &rzs->stats.bdev_num_reads);
bio->bi_bdev = rzs->backing_swap;
/*
@@ -718,7 +719,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
struct zobj_header *zheader;
unsigned char *user_mem, *cmem;
- stat_inc(rzs->stats.num_reads);
+ rzs_stat64_inc(rzs, &rzs->stats.num_reads);
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
@@ -752,7 +753,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
if (unlikely(ret != LZO_E_OK)) {
pr_err("Decompression failed! err=%d, page=%u\n",
ret, index);
- stat_inc(rzs->stats.failed_reads);
+ rzs_stat64_inc(rzs, &rzs->stats.failed_reads);
goto out;
}
@@ -776,7 +777,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
struct page *page, *page_store;
unsigned char *user_mem, *cmem, *src;
- stat_inc(rzs->stats.num_writes);
+ rzs_stat64_inc(rzs, &rzs->stats.num_writes);
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
@@ -796,7 +797,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
* Simply clear zero page flag.
*/
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
- stat_dec(rzs->stats.pages_zero);
+ rzs_stat_dec(&rzs->stats.pages_zero);
rzs_clear_flag(rzs, index, RZS_ZERO);
}
@@ -806,7 +807,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
if (page_zero_filled(user_mem)) {
kunmap_atomic(user_mem, KM_USER0);
mutex_unlock(&rzs->lock);
- stat_inc(rzs->stats.pages_zero);
+ rzs_stat_inc(&rzs->stats.pages_zero);
rzs_set_flag(rzs, index, RZS_ZERO);
set_bit(BIO_UPTODATE, &bio->bi_flags);
@@ -830,7 +831,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
if (unlikely(ret != LZO_E_OK)) {
mutex_unlock(&rzs->lock);
pr_err("Compression failed! err=%d\n", ret);
- stat_inc(rzs->stats.failed_writes);
+ rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
goto out;
}
@@ -853,13 +854,13 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
mutex_unlock(&rzs->lock);
pr_info("Error allocating memory for incompressible "
"page: %u\n", index);
- stat_inc(rzs->stats.failed_writes);
+ rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
goto out;
}
offset = 0;
rzs_set_flag(rzs, index, RZS_UNCOMPRESSED);
- stat_inc(rzs->stats.pages_expand);
+ rzs_stat_inc(&rzs->stats.pages_expand);
rzs->table[index].page = page_store;
src = kmap_atomic(page, KM_USER0);
goto memstore;
@@ -871,7 +872,7 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
mutex_unlock(&rzs->lock);
pr_info("Error allocating memory for compressed "
"page: %u, size=%zu\n", index, clen);
- stat_inc(rzs->stats.failed_writes);
+ rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
if (rzs->backing_swap)
fwd_write_request = 1;
goto out;
@@ -900,9 +901,9 @@ memstore:
/* Update stats */
rzs->stats.compr_size += clen;
- stat_inc(rzs->stats.pages_stored);
+ rzs_stat_inc(&rzs->stats.pages_stored);
if (clen <= PAGE_SIZE / 2)
- stat_inc(rzs->stats.good_compress);
+ rzs_stat_inc(&rzs->stats.good_compress);
mutex_unlock(&rzs->lock);
@@ -912,7 +913,7 @@ memstore:
out:
if (fwd_write_request) {
- stat_inc(rzs->stats.bdev_num_writes);
+ rzs_stat64_inc(rzs, &rzs->stats.bdev_num_writes);
bio->bi_bdev = rzs->backing_swap;
#if 0
/*
@@ -974,7 +975,7 @@ static int ramzswap_make_request(struct request_queue *queue, struct bio *bio)
}
if (!valid_swap_request(rzs, bio)) {
- stat_inc(rzs->stats.invalid_io);
+ rzs_stat64_inc(rzs, &rzs->stats.invalid_io);
bio_io_error(bio);
return 0;
}
@@ -1295,6 +1296,7 @@ static struct block_device_operations ramzswap_devops = {
static int create_device(struct ramzswap *rzs, int device_id)
{
mutex_init(&rzs->lock);
+ spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
rzs->queue = blk_alloc_queue(GFP_KERNEL);
diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h
index 7ba98bf..5b67222 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.h
+++ b/drivers/staging/ramzswap/ramzswap_drv.h
@@ -15,6 +15,9 @@
#ifndef _RAMZSWAP_DRV_H_
#define _RAMZSWAP_DRV_H_
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+
#include "ramzswap_ioctl.h"
#include "xvmalloc.h"
@@ -71,15 +74,6 @@ static const unsigned max_zpage_size_nobdev = PAGE_SIZE / 4 * 3;
#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT)
-/* Debugging and Stats */
-#if defined(CONFIG_RAMZSWAP_STATS)
-#define stat_inc(stat) ((stat)++)
-#define stat_dec(stat) ((stat)--)
-#else
-#define stat_inc(x)
-#define stat_dec(x)
-#endif
-
/* Flags for ramzswap pages (table[page_no].flags) */
enum rzs_pageflags {
/* Page is stored uncompressed */
@@ -124,6 +118,7 @@ struct ramzswap_stats {
u64 failed_reads; /* should NEVER! happen */
u64 failed_writes; /* can happen when memory is too low */
u64 invalid_io; /* non-swap I/O requests */
+ u64 notify_free; /* no. of swap slot free notifications */
u32 pages_zero; /* no. of zero filled pages */
u32 pages_stored; /* no. of pages currently stored */
u32 good_compress; /* % of pages with compression ratio<=50% */
@@ -138,6 +133,7 @@ struct ramzswap {
void *compress_workmem;
void *compress_buffer;
struct table *table;
+ spinlock_t stat64_lock; /* protect 64-bit stats */
struct mutex lock;
struct request_queue *queue;
struct gendisk *disk;
@@ -167,5 +163,48 @@ struct ramzswap {
/*-- */
-#endif
+/* Debugging and Stats */
+#if defined(CONFIG_RAMZSWAP_STATS)
+static void rzs_stat_inc(u32 *v)
+{
+ *v = *v + 1;
+}
+
+static void rzs_stat_dec(u32 *v)
+{
+ *v = *v - 1;
+}
+
+static void rzs_stat64_inc(struct ramzswap *rzs, u64 *v)
+{
+ spin_lock(&rzs->stat64_lock);
+ *v = *v + 1;
+ spin_unlock(&rzs->stat64_lock);
+}
+
+static void rzs_stat64_dec(struct ramzswap *rzs, u64 *v)
+{
+ spin_lock(&rzs->stat64_lock);
+ *v = *v - 1;
+ spin_unlock(&rzs->stat64_lock);
+}
+
+static u64 rzs_stat64_read(struct ramzswap *rzs, u64 *v)
+{
+ u64 val;
+
+ spin_lock(&rzs->stat64_lock);
+ val = *v;
+ spin_unlock(&rzs->stat64_lock);
+
+ return val;
+}
+#else
+#define rzs_stat_inc(v)
+#define rzs_stat_dec(v)
+#define rzs_stat64_inc(r, v)
+#define rzs_stat64_dec(r, v)
+#define rzs_stat64_read(r, v)
+#endif /* CONFIG_RAMZSWAP_STATS */
+#endif
diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h
index 1bc54e2..1edaeba 100644
--- a/drivers/staging/ramzswap/ramzswap_ioctl.h
+++ b/drivers/staging/ramzswap/ramzswap_ioctl.h
@@ -27,6 +27,7 @@ struct ramzswap_ioctl_stats {
u64 failed_reads; /* should NEVER! happen */
u64 failed_writes; /* can happen when memory is too low */
u64 invalid_io; /* non-swap I/O requests */
+ u64 notify_free; /* no. of swap slot free notifications */
u32 pages_zero; /* no. of zero filled pages */
u32 good_compress_pct; /* no. of pages with compression ratio<=50% */
u32 pages_expand_pct; /* no. of incompressible pages */
--
1.6.2.5
[replace stat_*() with rzs_stat*()]
---
ramzswap block size needs to be set to PAGE_SIZE
to avoid receiving any unaligned block I/O (happens
during swapon time). These unaligned access produce
unncessary I/O errors, scaring users.
Also included some minor cleanups.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/ramzswap_drv.c | 77 +++++++++++++++++------------
drivers/staging/ramzswap/ramzswap_drv.h | 2 +-
drivers/staging/ramzswap/ramzswap_ioctl.h | 2 +-
drivers/staging/ramzswap/xvmalloc.c | 2 +-
drivers/staging/ramzswap/xvmalloc.h | 2 +-
drivers/staging/ramzswap/xvmalloc_int.h | 2 +-
6 files changed, 50 insertions(+), 37 deletions(-)
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 3567ee3..5c93727 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
@@ -220,7 +220,7 @@ out:
return ret;
}
-void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
+static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
struct ramzswap_ioctl_stats *s)
{
strncpy(s->backing_swap_name, rzs->backing_swap_name,
@@ -502,6 +502,10 @@ static int setup_backing_swap(struct ramzswap *rzs)
goto bad_param;
}
disksize = i_size_read(inode);
+ if (!disksize) {
+ pr_err("Error reading backing swap size.\n");
+ goto bad_param;
+ }
} else if (S_ISREG(inode->i_mode)) {
bdev = inode->i_sb->s_bdev;
if (IS_SWAPFILE(inode)) {
@@ -519,7 +523,6 @@ static int setup_backing_swap(struct ramzswap *rzs)
rzs->swap_file = swap_file;
rzs->backing_swap = bdev;
rzs->disksize = disksize;
- BUG_ON(!rzs->disksize);
return 0;
@@ -537,7 +540,7 @@ out:
* Map logical page number 'pagenum' to physical page number
* on backing swap device. For block device, this is a nop.
*/
-u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
+static u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum)
{
u32 skip_pages, entries_per_page;
size_t delta, se_offset, skipped;
@@ -593,6 +596,10 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
u32 offset = rzs->table[index].offset;
if (unlikely(!page)) {
+ /*
+ * No memory is allocated for zero filled pages.
+ * Simply clear zero page flag.
+ */
if (rzs_test_flag(rzs, index, RZS_ZERO)) {
rzs_clear_flag(rzs, index, RZS_ZERO);
rzs_stat_dec(&rzs->stats.pages_zero);
@@ -664,7 +671,6 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
return 0;
}
-
/*
* Called when request page is not present in ramzswap.
* Its either in backing swap device (if present) or
@@ -782,24 +788,15 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
page = bio->bi_io_vec[0].bv_page;
index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
- src = rzs->compress_buffer;
-
/*
* System swaps to same sector again when the stored page
* is no longer referenced by any process. So, its now safe
* to free the memory that was allocated for this page.
*/
- if (rzs->table[index].page)
+ if (rzs->table[index].page || rzs_test_flag(rzs, index, RZS_ZERO))
ramzswap_free_page(rzs, index);
- /*
- * No memory is allocated for zero filled pages.
- * Simply clear zero page flag.
- */
- if (rzs_test_flag(rzs, index, RZS_ZERO)) {
- rzs_stat_dec(&rzs->stats.pages_zero);
- rzs_clear_flag(rzs, index, RZS_ZERO);
- }
+ src = rzs->compress_buffer;
mutex_lock(&rzs->lock);
@@ -941,7 +938,6 @@ out:
return 0;
}
-
/*
* Check if request is within bounds and page aligned.
*/
@@ -1069,6 +1065,7 @@ static void reset_device(struct ramzswap *rzs)
bd_release(rzs->backing_swap);
filp_close(rzs->swap_file, NULL);
rzs->backing_swap = NULL;
+ memset(rzs->backing_swap_name, 0, MAX_SWAP_NAME_LEN);
}
/* Reset stats */
@@ -1300,6 +1297,7 @@ static struct block_device_operations ramzswap_devops = {
static int create_device(struct ramzswap *rzs, int device_id)
{
+ int ret = 0;
mutex_init(&rzs->lock);
spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
@@ -1308,7 +1306,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
if (!rzs->queue) {
pr_err("Error allocating disk queue for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
blk_queue_make_request(rzs->queue, ramzswap_make_request);
@@ -1320,7 +1319,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
blk_cleanup_queue(rzs->queue);
pr_warning("Error allocating disk structure for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}
rzs->disk->major = ramzswap_major;
@@ -1335,10 +1335,16 @@ static int create_device(struct ramzswap *rzs, int device_id)
* or set equal to backing swap device (if provided)
*/
set_capacity(rzs->disk, 0);
+
+ blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE);
+ blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE);
+
add_disk(rzs->disk);
rzs->init_done = 0;
- return 1;
+
+out:
+ return ret;
}
static void destroy_device(struct ramzswap *rzs)
@@ -1354,18 +1360,20 @@ static void destroy_device(struct ramzswap *rzs)
static int __init ramzswap_init(void)
{
- int i, ret;
+ int ret, dev_id;
if (num_devices > max_num_devices) {
pr_warning("Invalid value for num_devices: %u\n",
num_devices);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
ramzswap_major = register_blkdev(0, "ramzswap");
if (ramzswap_major <= 0) {
pr_warning("Unable to get major number\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto out;
}
if (!num_devices) {
@@ -1376,21 +1384,26 @@ static int __init ramzswap_init(void)
/* Allocate the device array and initialize each one */
pr_info("Creating %u devices ...\n", num_devices);
devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
- if (!devices)
- goto out;
+ if (!devices) {
+ ret = -ENOMEM;
+ goto unregister;
+ }
- for (i = 0; i < num_devices; i++)
- if (!create_device(&devices[i], i)) {
- ret = i;
+ for (dev_id = 0; dev_id < num_devices; dev_id++) {
+ if (create_device(&devices[dev_id], dev_id)) {
+ ret = -ENOMEM;
goto free_devices;
}
+ }
+
return 0;
+
free_devices:
- for (i = 0; i < ret; i++)
- destroy_device(&devices[i]);
-out:
- ret = -ENOMEM;
+ while (dev_id)
+ destroy_device(&devices[--dev_id]);
+unregister:
unregister_blkdev(ramzswap_major, "ramzswap");
+out:
return ret;
}
diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h
index 5b67222..c7e0e76 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.h
+++ b/drivers/staging/ramzswap/ramzswap_drv.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h
index 1edaeba..d26076d 100644
--- a/drivers/staging/ramzswap/ramzswap_ioctl.h
+++ b/drivers/staging/ramzswap/ramzswap_ioctl.h
@@ -1,7 +1,7 @@
/*
* Compressed RAM based swap device
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.c b/drivers/staging/ramzswap/xvmalloc.c
index dabd266..3fdbb8a 100644
--- a/drivers/staging/ramzswap/xvmalloc.c
+++ b/drivers/staging/ramzswap/xvmalloc.c
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc.h b/drivers/staging/ramzswap/xvmalloc.h
index 010c6fe..5b1a81a 100644
--- a/drivers/staging/ramzswap/xvmalloc.h
+++ b/drivers/staging/ramzswap/xvmalloc.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
diff --git a/drivers/staging/ramzswap/xvmalloc_int.h b/drivers/staging/ramzswap/xvmalloc_int.h
index 263c72d..e23ed5c 100644
--- a/drivers/staging/ramzswap/xvmalloc_int.h
+++ b/drivers/staging/ramzswap/xvmalloc_int.h
@@ -1,7 +1,7 @@
/*
* xvmalloc memory allocator
*
- * Copyright (C) 2008, 2009 Nitin Gupta
+ * Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
--
1.6.2.5
On Thu, Jan 28, 2010 at 09:29:34AM +0530, Nitin Gupta wrote:
> [replace stat_*() with rzs_stat*()]
> ---
>
> ramzswap block size needs to be set to PAGE_SIZE
> to avoid receiving any unaligned block I/O (happens
> during swapon time). These unaligned access produce
> unncessary I/O errors, scaring users.
>
> Also included some minor cleanups.
Such as?
Could you break this into 2 patches, one the block size stuff, and the
other the cleanups? Remember, 1 patch does 1 thing.
thanks,
greg k-h
On Thu, Jan 28, 2010 at 9:53 AM, Greg KH <[email protected]> wrote:
> On Thu, Jan 28, 2010 at 09:29:34AM +0530, Nitin Gupta wrote:
>> [replace stat_*() with rzs_stat*()]
>> ---
>>
>> ramzswap block size needs to be set to PAGE_SIZE
>> to avoid receiving any unaligned block I/O (happens
>> during swapon time). These unaligned access produce
>> unncessary I/O errors, scaring users.
>>
>> Also included some minor cleanups.
>
> Such as?
>
> Could you break this into 2 patches, one the block size stuff, and the
> other the cleanups? ?Remember, 1 patch does 1 thing.
>
I thought large number of patches is not desirable, so I merged lot
of stuff in one. I will resend 'v2' patches with proper breakup.
Thanks,
Nitin
On Thu, Jan 28, 2010 at 11:07:20AM +0530, Nitin Gupta wrote:
> On Thu, Jan 28, 2010 at 9:53 AM, Greg KH <[email protected]> wrote:
> > On Thu, Jan 28, 2010 at 09:29:34AM +0530, Nitin Gupta wrote:
> >> [replace stat_*() with rzs_stat*()]
> >> ---
> >>
> >> ramzswap block size needs to be set to PAGE_SIZE
> >> to avoid receiving any unaligned block I/O (happens
> >> during swapon time). These unaligned access produce
> >> unncessary I/O errors, scaring users.
> >>
> >> Also included some minor cleanups.
> >
> > Such as?
> >
> > Could you break this into 2 patches, one the block size stuff, and the
> > other the cleanups? ?Remember, 1 patch does 1 thing.
> >
>
> I thought large number of patches is not desirable, so I merged lot
> of stuff in one. I will resend 'v2' patches with proper breakup.
Large numbers of patches is not only desirable, it is encouraged! Bring
them on, I get patch series all the time that start out [00/34] and
that's just fine.
And actually, doing things in small chunks is better if a problem is
found, as smaller patches are easier to review, and 'git bisect' makes
it trivial to narrow in on a specific patch.
thanks,
greg k-h