FreeBSD src
22054f8891
Report, on a periodic basis, the I/O latencies the CAM I/O scheduler computes. These times are only for the hardware portion of the I/O as measured from the time the operation is scheduled with the SIM using xpt_action() until the SIM reports it has completed with xpt_dine(). Any time the I/O operation spends in a software queue is no included. The P50 (median), P90, P99 and P99.9 statistics about the latency of each of the read, write and trim operations that completed during the polling interval are reported. If there are fewer than 2, 10, 100 or 1000 operations during the polling interval, no statistic is reported and a single dash '-' is displayed. The read, write and trim commands (either on the command line or at run time) toggle display of these operations. The color command toggles color (it defaults to on, like gstat). When color is enabled, unknown statistics are reported in blue, high latency for a statistics is reported in red, medium in magenta and low in green (as with gstat). The med= and hi= commands can set these latency thresholds. Limitations: The entire sysctl space for all the devices is walked for each polling period. This should be optimized to remember the OIDs and only do such polling with the xpt generation changes. There is also no way to filter devices displayed. This command only works on physical devies that are connected to SCSI, ATA or NVME sims as those are the only ones that are instrumented in the CAM I/O scheduler (the CAM_IOSCHED_DYNAMIC option must be in the kernel, and the dynamic scheduler can't be disabled). MFC After: 1 month Relnotes: yes Sponsored by: Netflix Reviewed by: pauamma_gundo.com, chs Differential Revision: https://reviews.freebsd.org/D34259 |
||
|---|---|---|
| .cirrus-ci | ||
| .github | ||
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .cirrus.yml | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README.md | ||
| RELNOTES | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory.
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
Source Roadmap:
| Directory | Description |
|---|---|
| bin | System/user commands. |
| cddl | Various commands and libraries under the Common Development and Distribution License. |
| contrib | Packages contributed by 3rd parties. |
| crypto | Cryptography stuff (see crypto/README). |
| etc | Template files for /etc. |
| gnu | Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
| include | System include files. |
| kerberos5 | Kerberos5 (Heimdal) package. |
| lib | System libraries. |
| libexec | System daemons. |
| release | Release building Makefile & associated tools. |
| rescue | Build system for statically linked /rescue utilities. |
| sbin | System commands. |
| secure | Cryptographic libraries and commands. |
| share | Shared resources. |
| stand | Boot loader sources. |
| sys | Kernel sources. |
sys/arch/conf |
Kernel configuration files. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. |
| tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
| tools | Utilities for regression testing and miscellaneous tasks. |
| usr.bin | User commands. |
| usr.sbin | System administration commands. |
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.