[PATCH] pktcdvd: Don't waste kernel memory
Allocate memory for read-gathering at open time, when it is known just how
much memory is needed. This avoids wasting kernel memory when the real packet
size is smaller than the maximum packet size supported by the driver. This is
always the case when using DVD discs.
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index cd16813..4e7dbcc 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -129,7 +129,7 @@
/*
* Allocate a packet_data struct
*/
-static struct packet_data *pkt_alloc_packet_data(void)
+static struct packet_data *pkt_alloc_packet_data(int frames)
{
int i;
struct packet_data *pkt;
@@ -138,11 +138,12 @@
if (!pkt)
goto no_pkt;
- pkt->w_bio = pkt_bio_alloc(PACKET_MAX_SIZE);
+ pkt->frames = frames;
+ pkt->w_bio = pkt_bio_alloc(frames);
if (!pkt->w_bio)
goto no_bio;
- for (i = 0; i < PAGES_PER_PACKET; i++) {
+ for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (!pkt->pages[i])
goto no_page;
@@ -150,7 +151,7 @@
spin_lock_init(&pkt->lock);
- for (i = 0; i < PACKET_MAX_SIZE; i++) {
+ for (i = 0; i < frames; i++) {
struct bio *bio = pkt_bio_alloc(1);
if (!bio)
goto no_rd_bio;
@@ -160,14 +161,14 @@
return pkt;
no_rd_bio:
- for (i = 0; i < PACKET_MAX_SIZE; i++) {
+ for (i = 0; i < frames; i++) {
struct bio *bio = pkt->r_bios[i];
if (bio)
bio_put(bio);
}
no_page:
- for (i = 0; i < PAGES_PER_PACKET; i++)
+ for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
if (pkt->pages[i])
__free_page(pkt->pages[i]);
bio_put(pkt->w_bio);
@@ -184,12 +185,12 @@
{
int i;
- for (i = 0; i < PACKET_MAX_SIZE; i++) {
+ for (i = 0; i < pkt->frames; i++) {
struct bio *bio = pkt->r_bios[i];
if (bio)
bio_put(bio);
}
- for (i = 0; i < PAGES_PER_PACKET; i++)
+ for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
__free_page(pkt->pages[i]);
bio_put(pkt->w_bio);
kfree(pkt);
@@ -204,17 +205,17 @@
list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
pkt_free_packet_data(pkt);
}
+ INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
}
static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
{
struct packet_data *pkt;
- INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
- INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
- spin_lock_init(&pd->cdrw.active_list_lock);
+ BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
+
while (nr_packets > 0) {
- pkt = pkt_alloc_packet_data();
+ pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
if (!pkt) {
pkt_shrink_pktlist(pd);
return 0;
@@ -949,7 +950,7 @@
pd->current_sector = zone + pd->settings.size;
pkt->sector = zone;
- pkt->frames = pd->settings.size >> 2;
+ BUG_ON(pkt->frames != pd->settings.size >> 2);
pkt->write_size = 0;
/*
@@ -1985,8 +1986,14 @@
if ((ret = pkt_set_segment_merging(pd, q)))
goto out_unclaim;
- if (write)
+ if (write) {
+ if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
+ printk("pktcdvd: not enough memory for buffers\n");
+ ret = -ENOMEM;
+ goto out_unclaim;
+ }
printk("pktcdvd: %lukB available on disc\n", lba << 1);
+ }
return 0;
@@ -2012,6 +2019,8 @@
pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
bd_release(pd->bdev);
blkdev_put(pd->bdev);
+
+ pkt_shrink_pktlist(pd);
}
static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
@@ -2377,12 +2386,6 @@
/* This is safe, since we have a reference from open(). */
__module_get(THIS_MODULE);
- if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
- printk("pktcdvd: not enough memory for buffers\n");
- ret = -ENOMEM;
- goto out_mem;
- }
-
pd->bdev = bdev;
set_blocksize(bdev, CD_FRAMESIZE);
@@ -2393,7 +2396,7 @@
if (IS_ERR(pd->cdrw.thread)) {
printk("pktcdvd: can't start kernel thread\n");
ret = -ENOMEM;
- goto out_thread;
+ goto out_mem;
}
proc = create_proc_entry(pd->name, 0, pkt_proc);
@@ -2404,8 +2407,6 @@
DPRINTK("pktcdvd: writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
return 0;
-out_thread:
- pkt_shrink_pktlist(pd);
out_mem:
blkdev_put(bdev);
/* This is safe: open() is still holding a reference. */
@@ -2501,6 +2502,10 @@
goto out_mem;
pd->disk = disk;
+ INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
+ INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
+ spin_lock_init(&pd->cdrw.active_list_lock);
+
spin_lock_init(&pd->lock);
spin_lock_init(&pd->iosched.lock);
sprintf(pd->name, "pktcdvd%d", idx);
@@ -2565,8 +2570,6 @@
blkdev_put(pd->bdev);
- pkt_shrink_pktlist(pd);
-
remove_proc_entry(pd->name, pkt_proc);
DPRINTK("pktcdvd: writer %s unmapped\n", pd->name);