Commit f1172283 authored by David Teigland's avatar David Teigland
Browse files

dlm: avoid scanning unchanged toss lists 



Keep track of whether a toss list contains any
shrinkable rsbs.  If not, dlm_scand can avoid
scanning the list for rsbs to shrink.  Unnecessary
scanning can otherwise waste a lot of time because
the toss lists can contain a large number of rsbs
that are non-shrinkable (directory records).

Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 2318aa27

fs/dlm/dlm_internal.h

+3 −0
Original line number Diff line number Diff line
@@ -96,10 +96,13 @@ do { \ 
}





#define DLM_RTF_SHRINK		0x00000001



struct dlm_rsbtable {

	struct rb_root		keep;

	struct rb_root		toss;

	spinlock_t		lock;

	uint32_t		flags;

};

fs/dlm/lock.c

+15 −0
Original line number Diff line number Diff line
@@ -1132,6 +1132,7 @@ static void toss_rsb(struct kref *kref) 
	rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep);

	rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss);

	r->res_toss_time = jiffies;

	ls->ls_rsbtbl[r->res_bucket].flags |= DLM_RTF_SHRINK;

	if (r->res_lvbptr) {

		dlm_free_lvb(r->res_lvbptr);

		r->res_lvbptr = NULL;
@@ -1659,11 +1660,18 @@ static void shrink_bucket(struct dlm_ls *ls, int b) 
	char *name;

	int our_nodeid = dlm_our_nodeid();

	int remote_count = 0;

	int need_shrink = 0;

	int i, len, rv;



	memset(&ls->ls_remove_lens, 0, sizeof(int) * DLM_REMOVE_NAMES_MAX);



	spin_lock(&ls->ls_rsbtbl[b].lock);



	if (!(ls->ls_rsbtbl[b].flags & DLM_RTF_SHRINK)) {

		spin_unlock(&ls->ls_rsbtbl[b].lock);

		return;

	}



	for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = next) {

		next = rb_next(n);

		r = rb_entry(n, struct dlm_rsb, res_hashnode);
@@ -1679,6 +1687,8 @@ static void shrink_bucket(struct dlm_ls *ls, int b) 
			continue;

		}



		need_shrink = 1;



		if (!time_after_eq(jiffies, r->res_toss_time +

				   dlm_config.ci_toss_secs * HZ)) {

			continue;
@@ -1710,6 +1720,11 @@ static void shrink_bucket(struct dlm_ls *ls, int b) 
		rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);

		dlm_free_rsb(r);

	}



	if (need_shrink)

		ls->ls_rsbtbl[b].flags |= DLM_RTF_SHRINK;

	else

		ls->ls_rsbtbl[b].flags &= ~DLM_RTF_SHRINK;

	spin_unlock(&ls->ls_rsbtbl[b].lock);



	/*

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