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Commit a5394d48 authored by Li Xi's avatar Li Xi Committed by Greg Kroah-Hartman
Browse files

staging: lustre: obdclass: change spinlock of key to rwlock 



Most of the time, keys are never changed. So rwlock might be
better for the concurrency of key read.

Signed-off-by: default avatarLi Xi <lixi@ddn.com>
Signed-off-by: default avatarGu Zheng <gzheng@ddn.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6800
Reviewed-on: http://review.whamcloud.com/15558


Reviewed-by: default avatarFaccini Bruno <bruno.faccini@intel.com>
Reviewed-by: default avatarJames Simmons <uja.ornl@yahoo.com>
Reviewed-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cf04968e

drivers/staging/lustre/lustre/obdclass/lu_object.c

+19 −19
Original line number Diff line number Diff line
@@ -1327,7 +1327,7 @@ enum { 


static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };



static DEFINE_SPINLOCK(lu_keys_guard);

static DEFINE_RWLOCK(lu_keys_guard);

static atomic_t lu_key_initing_cnt = ATOMIC_INIT(0);



/**
@@ -1351,7 +1351,7 @@ int lu_context_key_register(struct lu_context_key *key) 
	LASSERT(key->lct_tags != 0);



	result = -ENFILE;

	spin_lock(&lu_keys_guard);

	write_lock(&lu_keys_guard);

	for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {

		if (!lu_keys[i]) {

			key->lct_index = i;
@@ -1363,7 +1363,7 @@ int lu_context_key_register(struct lu_context_key *key) 
			break;

		}

	}

	spin_unlock(&lu_keys_guard);

	write_unlock(&lu_keys_guard);

	return result;

}

EXPORT_SYMBOL(lu_context_key_register);
@@ -1397,7 +1397,7 @@ void lu_context_key_degister(struct lu_context_key *key) 
	lu_context_key_quiesce(key);



	++key_set_version;

	spin_lock(&lu_keys_guard);

	write_lock(&lu_keys_guard);

	key_fini(&lu_shrink_env.le_ctx, key->lct_index);



	/**
@@ -1405,18 +1405,18 @@ void lu_context_key_degister(struct lu_context_key *key) 
	 * run lu_context_key::lct_fini() method.

	 */

	while (atomic_read(&key->lct_used) > 1) {

		spin_unlock(&lu_keys_guard);

		write_unlock(&lu_keys_guard);

		CDEBUG(D_INFO, "%s: \"%s\" %p, %d\n",

		       __func__, module_name(key->lct_owner),

		       key, atomic_read(&key->lct_used));

		schedule();

		spin_lock(&lu_keys_guard);

		write_lock(&lu_keys_guard);

	}

	if (lu_keys[key->lct_index]) {

		lu_keys[key->lct_index] = NULL;

		lu_ref_fini(&key->lct_reference);

	}

	spin_unlock(&lu_keys_guard);

	write_unlock(&lu_keys_guard);



	LASSERTF(atomic_read(&key->lct_used) == 1,

		 "key has instances: %d\n",
@@ -1536,7 +1536,7 @@ void lu_context_key_quiesce(struct lu_context_key *key) 
		/*

		 * XXX memory barrier has to go here.

		 */

		spin_lock(&lu_keys_guard);

		write_lock(&lu_keys_guard);

		key->lct_tags |= LCT_QUIESCENT;



		/**
@@ -1544,19 +1544,19 @@ void lu_context_key_quiesce(struct lu_context_key *key) 
		 * have completed.

		 */

		while (atomic_read(&lu_key_initing_cnt) > 0) {

			spin_unlock(&lu_keys_guard);

			write_unlock(&lu_keys_guard);

			CDEBUG(D_INFO, "%s: \"%s\" %p, %d (%d)\n",

			       __func__,

			       module_name(key->lct_owner),

			       key, atomic_read(&key->lct_used),

			atomic_read(&lu_key_initing_cnt));

			schedule();

			spin_lock(&lu_keys_guard);

			write_lock(&lu_keys_guard);

		}



		list_for_each_entry(ctx, &lu_context_remembered, lc_remember)

			key_fini(ctx, key->lct_index);

		spin_unlock(&lu_keys_guard);

		write_unlock(&lu_keys_guard);

		++key_set_version;

	}

}
@@ -1594,9 +1594,9 @@ static int keys_fill(struct lu_context *ctx) 
	 * An atomic_t variable is still used, in order not to reacquire the

	 * lock when decrementing the counter.

	 */

	spin_lock(&lu_keys_guard);

	read_lock(&lu_keys_guard);

	atomic_inc(&lu_key_initing_cnt);

	spin_unlock(&lu_keys_guard);

	read_unlock(&lu_keys_guard);



	LINVRNT(ctx->lc_value);

	for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
@@ -1665,9 +1665,9 @@ int lu_context_init(struct lu_context *ctx, __u32 tags) 
	ctx->lc_state = LCS_INITIALIZED;

	ctx->lc_tags = tags;

	if (tags & LCT_REMEMBER) {

		spin_lock(&lu_keys_guard);

		write_lock(&lu_keys_guard);

		list_add(&ctx->lc_remember, &lu_context_remembered);

		spin_unlock(&lu_keys_guard);

		write_unlock(&lu_keys_guard);

	} else {

		INIT_LIST_HEAD(&ctx->lc_remember);

	}
@@ -1693,10 +1693,10 @@ void lu_context_fini(struct lu_context *ctx) 
		keys_fini(ctx);



	} else { /* could race with key degister */

		spin_lock(&lu_keys_guard);

		write_lock(&lu_keys_guard);

		keys_fini(ctx);

		list_del_init(&ctx->lc_remember);

		spin_unlock(&lu_keys_guard);

		write_unlock(&lu_keys_guard);

	}

}

EXPORT_SYMBOL(lu_context_fini);
@@ -1724,7 +1724,7 @@ void lu_context_exit(struct lu_context *ctx) 
		for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {

			/* could race with key quiescency */

			if (ctx->lc_tags & LCT_REMEMBER)

				spin_lock(&lu_keys_guard);

				read_lock(&lu_keys_guard);

			if (ctx->lc_value[i]) {

				struct lu_context_key *key;
@@ -1734,7 +1734,7 @@ void lu_context_exit(struct lu_context *ctx) 
						      key, ctx->lc_value[i]);

			}

			if (ctx->lc_tags & LCT_REMEMBER)

				spin_unlock(&lu_keys_guard);

				read_unlock(&lu_keys_guard);

		}

	}

}