int64_t xbzrle_cache_resize(int64_t new_size)
{
if (new_size < TARGET_PAGE_SIZE) {
return -1;
}
if (XBZRLE.cache != NULL) {
return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
TARGET_PAGE_SIZE;
}
return pow2floor(new_size);
}
/*===========================================================================*
* set_blocksize *
*===========================================================================*/
void set_blocksize(struct super_block *sp)
{
int bufs;
cache_resize(sp->s_block_size, MINBUFS);
bufs = bufs_heuristic(sp);
cache_resize(sp->s_block_size, bufs);
/* Decide whether to use seconday cache or not.
* Only do this if
* - it's available, and
* - use of it hasn't been disabled for this fs, and
* - our main FS device isn't a memory device
*/
vmcache = 0;
if(vm_forgetblock(VM_BLOCKID_NONE) != ENOSYS &&
may_use_vmcache && major(sp->s_dev) != MEMORY_MAJOR) {
vmcache = 1;
}
}
/*===========================================================================*
* lmfs_set_blocksize *
*===========================================================================*/
void lmfs_set_blocksize(size_t new_block_size)
{
cache_resize(new_block_size, MINBUFS);
cache_heuristic_check();
/* Decide whether to use seconday cache or not.
* Only do this if the block size is a multiple of the page size, and using
* the VM cache has been enabled for this FS.
*/
vmcache = 0;
if(may_use_vmcache && !(new_block_size % PAGE_SIZE))
vmcache = 1;
}
static void cache_heuristic_check(void)
{
int bufs, d;
bufs = fs_bufs_heuristic(MINBUFS, fs_btotal, fs_bused, fs_block_size);
/* set the cache to the new heuristic size if the new one
* is more than 10% off from the current one.
*/
d = bufs-nr_bufs;
if(d < 0) d = -d;
if(d*100/nr_bufs > 10) {
cache_resize(fs_block_size, bufs);
}
}
/*===========================================================================*
* lmfs_set_blocksize *
*===========================================================================*/
void lmfs_set_blocksize(int new_block_size, int major)
{
cache_resize(new_block_size, MINBUFS);
cache_heuristic_check(major);
/* Decide whether to use seconday cache or not.
* Only do this if
* - it's available, and
* - use of it hasn't been disabled for this fs, and
* - our main FS device isn't a memory device
*/
vmcache = 0;
if(may_use_vmcache && !(new_block_size % PAGE_SIZE))
vmcache = 1;
}
static void cache_heuristic_check(int major)
{
int bufs, d;
u64_t btotal, bfree, bused;
fs_blockstats(&btotal, &bfree, &bused);
bufs = fs_bufs_heuristic(10, btotal, bfree,
fs_block_size, major);
/* set the cache to the new heuristic size if the new one
* is more than 10% off from the current one.
*/
d = bufs-nr_bufs;
if(d < 0) d = -d;
if(d*100/nr_bufs > 10) {
cache_resize(fs_block_size, bufs);
}
}