diff options
| author | Nicholas Bellinger <nab@daterainc.com> | 2013-09-23 23:12:42 +0400 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-10-02 08:40:55 +0400 |
| commit | 5f544cfac956971099e906f94568bc3fd1a7108a (patch) | |
| tree | 01693c400aeae3cf1fbaf26b54f7b55e083387d3 /drivers/target/tcm_fc/tfc_cmd.c | |
| parent | 15c03dd4859ab16f9212238f29dd315654aa94f6 (diff) | |
| download | linux-5f544cfac956971099e906f94568bc3fd1a7108a.tar.xz | |
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 <mark.d.rustad@intel.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>
Diffstat (limited to 'drivers/target/tcm_fc/tfc_cmd.c')
| -rw-r--r-- | drivers/target/tcm_fc/tfc_cmd.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c index 0e5a1caed176..479ec5621a4e 100644 --- a/drivers/target/tcm_fc/tfc_cmd.c +++ b/drivers/target/tcm_fc/tfc_cmd.c @@ -28,6 +28,7 @@ #include <linux/configfs.h> #include <linux/ctype.h> #include <linux/hash.h> +#include <linux/percpu_ida.h> #include <asm/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_host.h> @@ -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 */ |