Nicholas Bellinger 4a4caa29f1 iscsi-target: Pre-allocate more tags to avoid ack starvation ...

This patch addresses an traditional iscsi-target fabric ack starvation
issue where iscsit_allocate_cmd() -> percpu_ida_alloc_state() ends up
hitting slow path percpu-ida code, because iscsit_ack_from_expstatsn()
is expected to free ack'ed tags after tag allocation.

This is done to take into account the tags waiting to be acknowledged
and released in iscsit_ack_from_expstatsn(), but who's number are not
directly limited by the CmdSN Window queue_depth being enforced by
the target.

So that said, this patch bumps up the pre-allocated number of
per session tags to:

  (max(queue_depth, ISCSIT_MIN_TAGS) * 2) + ISCSIT_EXTRA_TAGS

for good measure to avoid the percpu_ida_alloc_state() slow path.

Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2014-01-19 10:59:05 +00:00

..

iscsi

iscsi-target: Pre-allocate more tags to avoid ack starvation

2014-01-19 10:59:05 +00:00

loopback

tcm_loop: Enable DIF/DIX modes in SCSI host LLD

2014-01-19 02:22:06 +00:00

sbp

target: Remove TF_CIT_TMPL macro

2013-10-16 13:35:02 -07:00

tcm_fc

drivers: target: Mark functions and structures as static in tfc_conf.c

2014-01-09 21:48:37 -08:00

Kconfig

target/iblock: Add blk_integrity + BIP passthrough support

2014-01-18 10:14:22 +00:00

Makefile

target: Add support for EXTENDED_COPY copy offload emulation

2013-09-10 16:48:43 -07:00

target_core_alua.c

target_core_alua: check for buffer overflow

2014-01-09 21:48:38 -08:00

target_core_alua.h

target_core_alua: Referrals configfs integration

2014-01-09 21:48:35 -08:00

target_core_configfs.c

target/configfs: Expose protection device attributes

2014-01-18 09:57:47 +00:00

target_core_device.c

target/configfs: Expose protection device attributes

2014-01-18 09:57:47 +00:00

target_core_fabric_configfs.c

target: Fix sizeof in kmalloc for some default_groups arrays

2013-12-16 12:42:20 -08:00

target_core_fabric_lib.c

target: Update copyright ownership/year information to 2013

2013-09-10 20:23:36 -07:00

target_core_file.c

target/file: Add DIF protection support to fd_execute_rw

2014-01-19 02:21:55 +00:00

target_core_file.h

target/file: Add DIF protection support to fd_execute_rw

2014-01-19 02:21:55 +00:00

target_core_hba.c

target: Update copyright ownership/year information to 2013

2013-09-10 20:23:36 -07:00

target_core_iblock.c

target/iblock: Add blk_integrity + BIP passthrough support

2014-01-18 10:14:22 +00:00

target_core_iblock.h

target: kill struct se_subsystem_dev

2012-11-06 20:55:43 -08:00

target_core_internal.h

target/configfs: Expose protection device attributes

2014-01-18 09:57:47 +00:00

target_core_pr.c

target core: rename (ex,im)plict -> (ex,im)plicit

2013-11-20 11:24:40 -08:00

target_core_pr.h

drivers: target: Move prototype declaration of function to header file target_core_pr.h

2014-01-09 21:48:36 -08:00

target_core_pscsi.c

target/pscsi: fix return value check

2013-10-25 10:42:09 -07:00

target_core_pscsi.h

target: kill struct se_subsystem_dev

2012-11-06 20:55:43 -08:00

target_core_rd.c

target/rd: Add DIF protection into rd_execute_rw

2014-01-19 02:22:06 +00:00

target_core_rd.h

target/rd: Add support for protection SGL setup + release

2014-01-19 02:22:05 +00:00

target_core_sbc.c

target/sbc: Add P_TYPE + PROT_EN bits to READ_CAPACITY_16

2014-01-18 09:53:13 +00:00

target_core_spc.c

target/spc: Expose ATO bit in control mode page

2014-01-18 09:53:14 +00:00

target_core_stat.c

target: Convert se_device statistics to atomic_long_t

2013-11-13 18:34:55 -08:00

target_core_tmr.c

target: Convert se_device statistics to atomic_long_t

2013-11-13 18:34:55 -08:00

target_core_tpg.c

target: Don't use void* when passing dev in core_tpg_add_lun

2013-12-16 13:29:20 -08:00

target_core_transport.c

target: Add protection SGLs to target_submit_cmd_map_sgls

2014-01-18 09:58:09 +00:00

target_core_ua.c

target: Remove unused ua_dev_list member in struct se_ua

2013-12-16 12:39:04 -08:00

target_core_ua.h

target core: rename (ex,im)plict -> (ex,im)plicit

2013-11-20 11:24:40 -08:00

target_core_xcopy.c

drivers: target: Move prototype declaration of function to header file target_core_pr.h

2014-01-09 21:48:36 -08:00

target_core_xcopy.h

target: Add support for EXTENDED_COPY copy offload emulation

2013-09-10 16:48:43 -07:00