Commit 8e316b9e authored by Ursula Braun's avatar Ursula Braun Committed by Jakub Kicinski
Browse files

net/smc: improve link group freeing 



Usually link groups are freed delayed to enable quick connection
creation for a follow-on SMC socket. Terminated link groups are
freed faster. This patch makes sure, fast schedule of link group
freeing is not rescheduled by a delayed schedule. And it makes sure
link group freeing is not rescheduled, if the real freeing is already
running.

Signed-off-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
parent 69318b52

net/smc/smc_core.c

+30 −17
Original line number Diff line number Diff line
@@ -61,14 +61,21 @@ static void smc_lgr_schedule_free_work(struct smc_link_group *lgr) 
	 * creation. For client use a somewhat higher removal delay time,

	 * otherwise there is a risk of out-of-sync link groups.

	 */

	if (!lgr->freeing && !lgr->freefast) {

		mod_delayed_work(system_wq, &lgr->free_work,

				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?

			 SMC_LGR_FREE_DELAY_CLNT : SMC_LGR_FREE_DELAY_SERV);

						SMC_LGR_FREE_DELAY_CLNT :

						SMC_LGR_FREE_DELAY_SERV);

	}

}



void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)

{

	mod_delayed_work(system_wq, &lgr->free_work, SMC_LGR_FREE_DELAY_FAST);

	if (!lgr->freeing && !lgr->freefast) {

		lgr->freefast = 1;

		mod_delayed_work(system_wq, &lgr->free_work,

				 SMC_LGR_FREE_DELAY_FAST);

	}

}



/* Register connection's alert token in our lookup structure.
@@ -171,10 +178,15 @@ static void smc_lgr_free_work(struct work_struct *work) 
						  struct smc_link_group,

						  free_work);

	spinlock_t *lgr_lock;

	struct smc_link *lnk;

	bool conns;



	smc_lgr_list_head(lgr, &lgr_lock);

	spin_lock_bh(lgr_lock);

	if (lgr->freeing) {

		spin_unlock_bh(lgr_lock);

		return;

	}

	read_lock_bh(&lgr->conns_lock);

	conns = RB_EMPTY_ROOT(&lgr->conns_all);

	read_unlock_bh(&lgr->conns_lock);
@@ -183,22 +195,21 @@ static void smc_lgr_free_work(struct work_struct *work) 
		return;

	}

	list_del_init(&lgr->list); /* remove from smc_lgr_list */

	spin_unlock_bh(lgr_lock);



	lnk = &lgr->lnk[SMC_SINGLE_LINK];

	if (!lgr->is_smcd && !lgr->terminating)	{

		struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];



		/* try to send del link msg, on error free lgr immediately */

		if (lnk->state == SMC_LNK_ACTIVE &&

		    !smc_link_send_delete(lnk)) {

			/* reschedule in case we never receive a response */

			smc_lgr_schedule_free_work(lgr);

			spin_unlock_bh(lgr_lock);

			return;

		}

	}



	if (!delayed_work_pending(&lgr->free_work)) {

		struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];

	lgr->freeing = 1; /* this instance does the freeing, no new schedule */

	spin_unlock_bh(lgr_lock);

	cancel_delayed_work(&lgr->free_work);



	if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)

		smc_llc_link_inactive(lnk);
@@ -206,7 +217,6 @@ static void smc_lgr_free_work(struct work_struct *work) 
		smc_ism_signal_shutdown(lgr);

	smc_lgr_free(lgr);

}

}



/* create a new SMC link group */

static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
@@ -233,6 +243,9 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini) 
	}

	lgr->is_smcd = ini->is_smcd;

	lgr->sync_err = 0;

	lgr->terminating = 0;

	lgr->freefast = 0;

	lgr->freeing = 0;

	lgr->vlan_id = ini->vlan_id;

	rwlock_init(&lgr->sndbufs_lock);

	rwlock_init(&lgr->rmbs_lock);
@@ -513,7 +526,7 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr) 
	read_unlock_bh(&lgr->conns_lock);

	if (!lgr->is_smcd)

		wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);

	smc_lgr_schedule_free_work(lgr);

	smc_lgr_schedule_free_work_fast(lgr);

}



/* unlink and terminate link group */

net/smc/smc_core.h

+2 −0
Original line number Diff line number Diff line
@@ -204,6 +204,8 @@ struct smc_link_group { 
	struct delayed_work	free_work;	/* delayed freeing of an lgr */

	u8			sync_err : 1;	/* lgr no longer fits to peer */

	u8			terminating : 1;/* lgr is terminating */

	u8			freefast : 1;	/* free worker scheduled fast */

	u8			freeing : 1;	/* lgr is being freed */



	bool			is_smcd;	/* SMC-R or SMC-D */

	union {

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