mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
synced 2026-10-16 22:39:48 +00:00
No description
- C 96.9%
- Assembly 0.9%
- Rust 0.6%
- Shell 0.6%
- Python 0.5%
- Other 0.3%
57f7225a4f
The shost->can_queue value is initially used to set per-HW queue context tag depth in the block layer. This ensures that the shost is not sent too many commands which it can deal with. However lowering sdebug_max_queue separately means that we can easily overload the shost, as in the following example: $ cat /sys/bus/pseudo/drivers/scsi_debug/max_queue 192 $ cat /sys/class/scsi_host/host0/can_queue 192 $ echo 100 > /sys/bus/pseudo/drivers/scsi_debug/max_queue $ cat /sys/class/scsi_host/host0/can_queue 192 $ fio --filename=/dev/sda --direct=1 --rw=read --bs=4k --iodepth=256 --runtime=1200 --numjobs=10 --time_based --group_reporting --name=iops-test-job --eta-newline=1 --readonly --ioengine=io_uring --hipri --exitall_on_error iops-test-job: (g=0): rw=read, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=256 ... fio-3.28 Starting 10 processes [ 111.269885] scsi_io_completion_action: 400 callbacks suppressed [ 111.269885] blk_print_req_error: 400 callbacks suppressed [ 111.269889] I/O error, dev sda, sector 440 op 0x0:(READ) flags 0x1200000 phys_seg 1 prio class 2 [ 111.269892] sd 0:0:0:0: [sda] tag#132 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s [ 111.269897] sd 0:0:0:0: [sda] tag#132 CDB: Read(10) 28 00 00 00 01 68 00 00 08 00 [ 111.277058] I/O error, dev sda, sector 360 op 0x0:(READ) flags 0x1200000 phys_seg 1 prio class 2 [...] Ensure that this cannot happen by allowing sdebug_max_queue be modified only when we have no shosts. As such, any shost->can_queue value will match sdebug_max_queue, and sdebug_max_queue cannot be modified separately. Since retired_max_queue is no longer set, remove support. Continue to apply the restriction that sdebug_host_max_queue cannot be modified when sdebug_host_max_queue is set. Adding support for that would mean extra code, and no one has complained about this restriction previously. A command like the following may be used to remove a shost: echo -1 > /sys/bus/pseudo/drivers/scsi_debug/add_host Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20230327074310.1862889-11-john.g.garry@oracle.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
History
|
|
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.