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[PATCH] nbd: Don't create all MAX_NBD devices by default all the time 

This patches adds the "nbds_max" parameter to the nbd kernel module, which
limits the number of nbds allocated.  Previously, always all 128 entries
were allocated unconditionally, which used to waste resources and
needlessly flood the hotplug system with events.  (Defaults to 16 now.)

Signed-off-by: Lars Marowsky-Bree <lmb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Lars Marowsky-Bree 2005-05-01 08:59:07 -07:00 committed by Linus Torvalds
parent 4750e2c0c5
commit 40be0c28b3
1 changed files with 13 additions and 3 deletions
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16
drivers/block/nbd.c
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@ -78,6 +78,7 @@
#define DBG_RX 0x0200
#define DBG_TX 0x0400
static unsigned int debugflags;
static unsigned int nbds_max = 16;
#endif /* NDEBUG */
static struct nbd_device nbd_dev[MAX_NBD];
@ -647,7 +648,13 @@ static int __init nbd_init(void)
return -EIO;
}
for (i = 0; i < MAX_NBD; i++) {
if (nbds_max > MAX_NBD) {
printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD,
nbds_max);
return -EINVAL;
}
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = alloc_disk(1);
if (!disk)
goto out;
@ -673,7 +680,7 @@ static int __init nbd_init(void)
dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
devfs_mk_dir("nbd");
for (i = 0; i < MAX_NBD; i++) {
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
nbd_dev[i].file = NULL;
nbd_dev[i].magic = LO_MAGIC;
@ -706,8 +713,9 @@ static int __init nbd_init(void)
static void __exit nbd_cleanup(void)
{
int i;
for (i = 0; i < MAX_NBD; i++) {
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
nbd_dev[i].magic = 0;
if (disk) {
del_gendisk(disk);
blk_cleanup_queue(disk->queue);
@ -725,6 +733,8 @@ module_exit(nbd_cleanup);
MODULE_DESCRIPTION("Network Block Device");
MODULE_LICENSE("GPL");
module_param(nbds_max, int, 0444);
MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
#ifndef NDEBUG
module_param(debugflags, int, 0644);
MODULE_PARM_DESC(debugflags, "flags for controlling debug output");