From d72d827f2f2636d8d72f0f3ebe5b661c9a24d343 Mon Sep 17 00:00:00 2001 From: Mingzhe Zou Date: Tue, 1 Mar 2022 15:55:00 +0800 Subject: scsi: target: Add iscsi/cpus_allowed_list in configfs The RX/TX threads for iSCSI connection can be scheduled to any online CPUs, and will not be rescheduled. When binding other heavy load threads along with iSCSI connection RX/TX thread to the same CPU, the iSCSI performance will be worse. Add iscsi/cpus_allowed_list in configfs. The available CPU set of iSCSI connection RX/TX threads is allowed_cpus & online_cpus. If it is modified, all RX/TX threads will be rescheduled. Link: https://lore.kernel.org/r/20220301075500.14266-1-mingzhe.zou@easystack.cn Reviewed-by: Mike Christie Signed-off-by: Mingzhe Zou Signed-off-by: Martin K. Petersen --- drivers/target/iscsi/iscsi_target.c | 77 ++++++++++++++++++++++++++-- drivers/target/iscsi/iscsi_target_configfs.c | 32 ++++++++++++ drivers/target/iscsi/iscsi_target_login.c | 8 +++ 3 files changed, 114 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 2c54c5d8412d..6fe6a6bab3f4 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -702,13 +702,19 @@ static int __init iscsi_target_init_module(void) if (!iscsit_global->ts_bitmap) goto configfs_out; + if (!zalloc_cpumask_var(&iscsit_global->allowed_cpumask, GFP_KERNEL)) { + pr_err("Unable to allocate iscsit_global->allowed_cpumask\n"); + goto bitmap_out; + } + cpumask_setall(iscsit_global->allowed_cpumask); + lio_qr_cache = kmem_cache_create("lio_qr_cache", sizeof(struct iscsi_queue_req), __alignof__(struct iscsi_queue_req), 0, NULL); if (!lio_qr_cache) { pr_err("Unable to kmem_cache_create() for" " lio_qr_cache\n"); - goto bitmap_out; + goto cpumask_out; } lio_dr_cache = kmem_cache_create("lio_dr_cache", @@ -753,6 +759,8 @@ dr_out: kmem_cache_destroy(lio_dr_cache); qr_out: kmem_cache_destroy(lio_qr_cache); +cpumask_out: + free_cpumask_var(iscsit_global->allowed_cpumask); bitmap_out: vfree(iscsit_global->ts_bitmap); configfs_out: @@ -782,6 +790,7 @@ static void __exit iscsi_target_cleanup_module(void) target_unregister_template(&iscsi_ops); + free_cpumask_var(iscsit_global->allowed_cpumask); vfree(iscsit_global->ts_bitmap); kfree(iscsit_global); } @@ -3587,6 +3596,11 @@ static int iscsit_send_reject( void iscsit_thread_get_cpumask(struct iscsi_conn *conn) { int ord, cpu; + cpumask_t conn_allowed_cpumask; + + cpumask_and(&conn_allowed_cpumask, iscsit_global->allowed_cpumask, + cpu_online_mask); + /* * bitmap_id is assigned from iscsit_global->ts_bitmap from * within iscsit_start_kthreads() @@ -3595,8 +3609,9 @@ void iscsit_thread_get_cpumask(struct iscsi_conn *conn) * iSCSI connection's RX/TX threads will be scheduled to * execute upon. */ - ord = conn->bitmap_id % cpumask_weight(cpu_online_mask); - for_each_online_cpu(cpu) { + cpumask_clear(conn->conn_cpumask); + ord = conn->bitmap_id % cpumask_weight(&conn_allowed_cpumask); + for_each_cpu(cpu, &conn_allowed_cpumask) { if (ord-- == 0) { cpumask_set_cpu(cpu, conn->conn_cpumask); return; @@ -3609,6 +3624,62 @@ void iscsit_thread_get_cpumask(struct iscsi_conn *conn) cpumask_setall(conn->conn_cpumask); } +static void iscsit_thread_reschedule(struct iscsi_conn *conn) +{ + /* + * If iscsit_global->allowed_cpumask modified, reschedule iSCSI + * connection's RX/TX threads update conn->allowed_cpumask. + */ + if (!cpumask_equal(iscsit_global->allowed_cpumask, + conn->allowed_cpumask)) { + iscsit_thread_get_cpumask(conn); + conn->conn_tx_reset_cpumask = 1; + conn->conn_rx_reset_cpumask = 1; + cpumask_copy(conn->allowed_cpumask, + iscsit_global->allowed_cpumask); + } +} + +void iscsit_thread_check_cpumask( + struct iscsi_conn *conn, + struct task_struct *p, + int mode) +{ + /* + * The TX and RX threads maybe call iscsit_thread_check_cpumask() + * at the same time. The RX thread might be faster and return from + * iscsit_thread_reschedule() with conn_rx_reset_cpumask set to 0. + * Then the TX thread sets it back to 1. + * The next time the RX thread loops, it sees conn_rx_reset_cpumask + * set to 1 and calls set_cpus_allowed_ptr() again and set it to 0. + */ + iscsit_thread_reschedule(conn); + + /* + * mode == 1 signals iscsi_target_tx_thread() usage. + * mode == 0 signals iscsi_target_rx_thread() usage. + */ + if (mode == 1) { + if (!conn->conn_tx_reset_cpumask) + return; + } else { + if (!conn->conn_rx_reset_cpumask) + return; + } + + /* + * Update the CPU mask for this single kthread so that + * both TX and RX kthreads are scheduled to run on the + * same CPU. + */ + set_cpus_allowed_ptr(p, conn->conn_cpumask); + if (mode == 1) + conn->conn_tx_reset_cpumask = 0; + else + conn->conn_rx_reset_cpumask = 0; +} +EXPORT_SYMBOL(iscsit_thread_check_cpumask); + int iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state) { diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c index 2a9de24a8bbe..0cedcfe207b5 100644 --- a/drivers/target/iscsi/iscsi_target_configfs.c +++ b/drivers/target/iscsi/iscsi_target_configfs.c @@ -1127,8 +1127,40 @@ static ssize_t lio_target_wwn_lio_version_show(struct config_item *item, CONFIGFS_ATTR_RO(lio_target_wwn_, lio_version); +static ssize_t lio_target_wwn_cpus_allowed_list_show( + struct config_item *item, char *page) +{ + return sprintf(page, "%*pbl\n", + cpumask_pr_args(iscsit_global->allowed_cpumask)); +} + +static ssize_t lio_target_wwn_cpus_allowed_list_store( + struct config_item *item, const char *page, size_t count) +{ + int ret; + char *orig; + cpumask_t new_allowed_cpumask; + + orig = kstrdup(page, GFP_KERNEL); + if (!orig) + return -ENOMEM; + + cpumask_clear(&new_allowed_cpumask); + ret = cpulist_parse(orig, &new_allowed_cpumask); + + kfree(orig); + if (ret != 0) + return ret; + + cpumask_copy(iscsit_global->allowed_cpumask, &new_allowed_cpumask); + return count; +} + +CONFIGFS_ATTR(lio_target_wwn_, cpus_allowed_list); + static struct configfs_attribute *lio_target_wwn_attrs[] = { &lio_target_wwn_attr_lio_version, + &lio_target_wwn_attr_cpus_allowed_list, NULL, }; diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 1a9c50401bdb..9c01fb864585 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -1129,8 +1129,15 @@ static struct iscsi_conn *iscsit_alloc_conn(struct iscsi_np *np) goto free_conn_ops; } + if (!zalloc_cpumask_var(&conn->allowed_cpumask, GFP_KERNEL)) { + pr_err("Unable to allocate conn->allowed_cpumask\n"); + goto free_conn_cpumask; + } + return conn; +free_conn_cpumask: + free_cpumask_var(conn->conn_cpumask); free_conn_ops: kfree(conn->conn_ops); put_transport: @@ -1142,6 +1149,7 @@ free_conn: void iscsit_free_conn(struct iscsi_conn *conn) { + free_cpumask_var(conn->allowed_cpumask); free_cpumask_var(conn->conn_cpumask); kfree(conn->conn_ops); iscsit_put_transport(conn->conn_transport); -- cgit v1.2.3