/*
* could be called frequently for query (@nr_to_scan == 0).
* we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
*/
static int enc_pools_shrink(int nr_to_scan, unsigned int gfp_mask)
{
if (unlikely(nr_to_scan != 0)) {
cfs_spin_lock(&page_pools.epp_lock);
nr_to_scan = min(nr_to_scan, (int) page_pools.epp_free_pages -
PTLRPC_MAX_BRW_PAGES);
if (nr_to_scan > 0) {
enc_pools_release_free_pages(nr_to_scan);
CDEBUG(D_SEC, "released %d pages, %ld left\n",
nr_to_scan, page_pools.epp_free_pages);
page_pools.epp_st_shrinks++;
page_pools.epp_last_shrink = cfs_time_current_sec();
}
cfs_spin_unlock(&page_pools.epp_lock);
}
/*
* if no pool access for a long time, we consider it's fully idle.
* a little race here is fine.
*/
if (unlikely(cfs_time_current_sec() - page_pools.epp_last_access >
CACHE_QUIESCENT_PERIOD)) {
cfs_spin_lock(&page_pools.epp_lock);
page_pools.epp_idle_idx = IDLE_IDX_MAX;
cfs_spin_unlock(&page_pools.epp_lock);
}
LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
return max((int) page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES, 0) *
(IDLE_IDX_MAX - page_pools.epp_idle_idx) / IDLE_IDX_MAX;
}
/*
* we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
*/
static unsigned long enc_pools_shrink_scan(struct shrinker *s,
struct shrink_control *sc)
{
spin_lock(&page_pools.epp_lock);
sc->nr_to_scan = min_t(unsigned long, sc->nr_to_scan,
page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES);
if (sc->nr_to_scan > 0) {
enc_pools_release_free_pages(sc->nr_to_scan);
CDEBUG(D_SEC, "released %ld pages, %ld left\n",
(long)sc->nr_to_scan, page_pools.epp_free_pages);
page_pools.epp_st_shrinks++;
page_pools.epp_last_shrink = ktime_get_seconds();
}
spin_unlock(&page_pools.epp_lock);
/*
* if no pool access for a long time, we consider it's fully idle.
* a little race here is fine.
*/
if (unlikely(ktime_get_seconds() - page_pools.epp_last_access >
CACHE_QUIESCENT_PERIOD)) {
spin_lock(&page_pools.epp_lock);
page_pools.epp_idle_idx = IDLE_IDX_MAX;
spin_unlock(&page_pools.epp_lock);
}
LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
return sc->nr_to_scan;
}
/*
* could be called frequently for query (@nr_to_scan == 0).
* we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
*/
static int enc_pools_shrink(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask))
{
if (unlikely(shrink_param(sc, nr_to_scan) != 0)) {
spin_lock(&page_pools.epp_lock);
shrink_param(sc, nr_to_scan) = min_t(unsigned long,
shrink_param(sc, nr_to_scan),
page_pools.epp_free_pages -
PTLRPC_MAX_BRW_PAGES);
if (shrink_param(sc, nr_to_scan) > 0) {
enc_pools_release_free_pages(shrink_param(sc,
nr_to_scan));
CDEBUG(D_SEC, "released %ld pages, %ld left\n",
(long)shrink_param(sc, nr_to_scan),
page_pools.epp_free_pages);
page_pools.epp_st_shrinks++;
page_pools.epp_last_shrink = cfs_time_current_sec();
}
spin_unlock(&page_pools.epp_lock);
}