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| author | Roland Dreier <roland@purestorage.com> | 2015-07-23 14:53:32 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-08-02 23:11:52 -0700 |
| commit | 109e2381749c1cfd94a0d22b2b54142539024973 (patch) | |
| tree | 9695ecd3738a7bad43edcca4eb641339e7a30060 /include/target | |
| parent | 24c7d6c7316c72301bf8ecfc1189fd476176fd75 (diff) | |
| download | linux-109e2381749c1cfd94a0d22b2b54142539024973.tar.gz linux-109e2381749c1cfd94a0d22b2b54142539024973.tar.bz2 linux-109e2381749c1cfd94a0d22b2b54142539024973.zip | |
target: Drop iSCSI use of mutex around max_cmd_sn increment
In a performance profile, taking a mutex in iscsit_increment_maxcmdsn()
shows up very high. However taking a mutex around "sess->max_cmd_sn += 1"
seems pretty silly: we're not serializing against other contexts in
any useful way.
I did a quick audit and there don't appear to be any other places that
use max_cmd_sn within the mutex more than once, so this lock can't be
providing any useful serialization.
(Get correct values for logging - fix whitespace damage)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target')
| -rw-r--r-- | include/target/iscsi/iscsi_target_core.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h index ab465858f462..d4616ef12e04 100644 --- a/include/target/iscsi/iscsi_target_core.h +++ b/include/target/iscsi/iscsi_target_core.h @@ -637,7 +637,7 @@ struct iscsi_session { /* session wide counter: expected command sequence number */ u32 exp_cmd_sn; /* session wide counter: maximum allowed command sequence number */ - u32 max_cmd_sn; + atomic_t max_cmd_sn; struct list_head sess_ooo_cmdsn_list; /* LIO specific session ID */ |