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| author |   Mike Christie <michael.christie@oracle.com> | 2021-09-29 21:04:21 -0500 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2021-10-18 22:38:36 -0400 |
| commit | 7324f47d4293ff50f489010735a4057defb1a5d6 (patch) | |
| tree | 67eadcd82db8a482dfba6802d7a05929288a0091 /include/target | |
| parent | scsi: target: Fix alua_tg_pt_gps_count tracking (diff) | |
| download | wireguard-linux-7324f47d4293ff50f489010735a4057defb1a5d6.tar.xz wireguard-linux-7324f47d4293ff50f489010735a4057defb1a5d6.zip | |
scsi: target: Replace lun_tg_pt_gp_lock with rcu in I/O path
We are only holding the lun_tg_pt_gp_lock in target_alua_state_check() to
make sure tg_pt_gp is not freed from under us while we copy the state,
delay, ID values. We can instead use RCU here to access the tg_pt_gp.
With this patch IOPs can increase up to 10% for jobs like:
fio --filename=/dev/sdX --direct=1 --rw=randrw --bs=4k \
--ioengine=libaio --iodepth=64 --numjobs=N
when there are multiple sessions (running that fio command to each /dev/sdX
or using multipath and there are over 8 paths), or more than 8 queues for
the loop or vhost with multiple threads case and numjobs > 8.
Link: https://lore.kernel.org/r/20210930020422.92578-5-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/target')
| -rw-r--r-- | include/target/target_core_base.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index a7600b311b84..c2b36f7d917d 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -749,7 +749,7 @@ struct se_lun { /* ALUA target port group linkage */ struct list_head lun_tg_pt_gp_link; - struct t10_alua_tg_pt_gp *lun_tg_pt_gp; + struct t10_alua_tg_pt_gp __rcu *lun_tg_pt_gp; spinlock_t lun_tg_pt_gp_lock; struct se_portal_group *lun_tpg; |