From 5f544cfac956971099e906f94568bc3fd1a7108a Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 23 Sep 2013 12:12:42 -0700 Subject: [PATCH] tcm_fc: Convert to per-cpu command map pre-allocation of ft_cmd This patch converts tcm_fc to use transport_init_session_tags() pre-allocation logic for struct ft_cmd descriptors using per-cpu session tag pooling in order to effectively avoid memory allocation + release for each received I/O. It adds percpu_ida_alloc() in ft_recv_cmd() to obtain an tag and locate ft_cmd from se_sess->sess_cmd_map[], and percpu_ida_free() in ft_free_cmd() to release the tag based upon se_cmd->map_tag id. It also uses a TCM_FC_DEFAULT_TAGS value of 512, that puts the per se_sess->sess_cmd_map allocation at ~360K on 64-bit. v2 changes: - Handle possible tag < 0 failure with GFP_ATOMIC Cc: Mark Rustad Cc: Robert Love Cc: Kent Overstreet Signed-off-by: Nicholas Bellinger --- drivers/target/tcm_fc/tcm_fc.h | 1 + drivers/target/tcm_fc/tfc_cmd.c | 18 ++++++++++++++---- drivers/target/tcm_fc/tfc_sess.c | 3 ++- 3 files changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/target/tcm_fc/tcm_fc.h b/drivers/target/tcm_fc/tcm_fc.h index 0dd54a4..752863a 100644 --- a/drivers/target/tcm_fc/tcm_fc.h +++ b/drivers/target/tcm_fc/tcm_fc.h @@ -22,6 +22,7 @@ #define FT_NAMELEN 32 /* length of ASCII WWPNs including pad */ #define FT_TPG_NAMELEN 32 /* max length of TPG name */ #define FT_LUN_NAMELEN 32 /* max length of LUN name */ +#define TCM_FC_DEFAULT_TAGS 512 /* tags used for per-session preallocation */ struct ft_transport_id { __u8 format; diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c index 0e5a1cae..479ec56 100644 --- a/drivers/target/tcm_fc/tfc_cmd.c +++ b/drivers/target/tcm_fc/tfc_cmd.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -89,16 +90,18 @@ static void ft_free_cmd(struct ft_cmd *cmd) { struct fc_frame *fp; struct fc_lport *lport; + struct se_session *se_sess; if (!cmd) return; + se_sess = cmd->sess->se_sess; fp = cmd->req_frame; lport = fr_dev(fp); if (fr_seq(fp)) lport->tt.seq_release(fr_seq(fp)); fc_frame_free(fp); + percpu_ida_free(&se_sess->sess_tag_pool, cmd->se_cmd.map_tag); ft_sess_put(cmd->sess); /* undo get from lookup at recv */ - kfree(cmd); } void ft_release_cmd(struct se_cmd *se_cmd) @@ -432,14 +435,21 @@ static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp) { struct ft_cmd *cmd; struct fc_lport *lport = sess->tport->lport; + struct se_session *se_sess = sess->se_sess; + int tag; - cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC); - if (!cmd) + tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC); + if (tag < 0) goto busy; + + cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag]; + memset(cmd, 0, sizeof(struct ft_cmd)); + + cmd->se_cmd.map_tag = tag; cmd->sess = sess; cmd->seq = lport->tt.seq_assign(lport, fp); if (!cmd->seq) { - kfree(cmd); + percpu_ida_free(&se_sess->sess_tag_pool, tag); goto busy; } cmd->req_frame = fp; /* hold frame during cmd */ diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c index 4859505..ae52c08 100644 --- a/drivers/target/tcm_fc/tfc_sess.c +++ b/drivers/target/tcm_fc/tfc_sess.c @@ -210,7 +210,8 @@ static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id, if (!sess) return NULL; - sess->se_sess = transport_init_session(); + sess->se_sess = transport_init_session_tags(TCM_FC_DEFAULT_TAGS, + sizeof(struct ft_cmd)); if (IS_ERR(sess->se_sess)) { kfree(sess); return NULL; -- 2.7.4