In some cases, like with multiple LUN targets or where the target has to
respond to transport level requests from the receiving context it can be
better to defer cmd submission to a helper thread. If the backend driver
blocks on something like request/tag allocation it can block the entire
target submission path and other LUs and transport IO on that session.
In other cases like single LUN targets with storage that can support all
the commands that the target can queue, then it's best to submit the cmd
to the backend from the target's cmd receiving context.
Subsequent commits will allow the user to config what they prefer, but
drivers like loop can't directly submit because they can be called from a
context that can't sleep. And, drivers like vhost-scsi can support direct
submission, but need to keep their default behavior of deferring execution
to avoid possible regressions where the backend can block.
Make the drivers tell LIO core if they support direct submissions and their
current default, so we can prevent users from misconfiguring the system and
initialize devices correctly.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230928020907.5730-2-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Merge the 5.15/scsi-fixes branch into the staging tree to resolve UFS
conflict reported by sfr.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Under the session level spinlock node->active_ios_lock in
efct_scsi_io_alloc() we are taking another spinlock for the port. This
leads to contention between sessions and even between I/Os in the same
session.
Reduce the locked region to active_ios list for which active_ios_lock is
intended. Spinlock CPU usage decreases from 18% down to 13%. IOPS are
increased from 220 kIOPS to 264 kIOPS for one LUN.
Link: https://lore.kernel.org/r/20210914105539.6942-4-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Smatch checker reported the following error:
drivers/base/power/sysfs.c:833 dpm_sysfs_remove()
warn: sleeping in atomic context
With a calling sequence of:
efct_lio_npiv_drop_nport() <- disables preempt
-> fc_vport_terminate()
-> device_del()
-> dpm_sysfs_remove()
Issue is efct_lio_npiv_drop_nport() is making the fc_vport_terminate() call
while holding a lock w/ ipl raised.
It is unnecessary to hold the lock over this call, shift where the lock is
taken.
Link: https://lore.kernel.org/r/20210907165225.10821-1-jsmart2021@gmail.com
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Co-developed-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Pull Kbuild updates from Masahiro Yamada:
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kbuild: redo fake deps at include/ksym/*.h
kbuild: clean up objtool_args slightly
modpost: get the *.mod file path more simply
checkkconfigsymbols.py: Fix the '--ignore' option
kbuild: merge vmlinux_link() between ARCH=um and other architectures
kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
kbuild: remove stale *.symversions
kbuild: remove unused quiet_cmd_update_lto_symversions
gen_compile_commands: extract compiler command from a series of commands
x86: remove cc-option-yn test for -mtune=
arc: replace cc-option-yn uses with cc-option
s390: replace cc-option-yn uses with cc-option
ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
sparc: move the install rule to arch/sparc/Makefile
security: remove unneeded subdir-$(CONFIG_...)
kbuild: sh: remove unused install script
kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
kbuild: Switch to 'f' variants of integrated assembler flag
kbuild: Shuffle blank line to improve comment meaning
...
Delete/fixup few includes in anticipation of global -isystem compile
option removal.
Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
debugfs_create_xxx routines, which return pointers, are being checked for
error by looking for NULL values. The routines may return pointer-munged
-Exxx codes, so they should be using IS_ERR() to adapt.
There are two cases:
- The first case is on initial directory creation, which actually doesn't
need to be checked. So remove the check.
- Creation of the sessions subdirectory. Modify this creation to create
under the initial directory created, and fix failure check.
Link: https://lore.kernel.org/r/20210618233004.83769-1-jsmart2021@gmail.com
Fixes: 4df84e8466 ("scsi: elx: efct: Driver initialization routines")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
efct_hw_iotype_is_originator() is returning a negative (-EIO) status which
doesn't make sense for a u8 function type.
Reviewing the code, the function only needs to return true/false, thus a
bool status is most appropriate.
Change the function return type and patch up the one callee as the bool
inverses the if check.
Link: https://lore.kernel.org/r/20210618231524.83179-1-jsmart2021@gmail.com
Fixes: 4df84e8466 ("scsi: elx: efct: Driver initialization routines")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>