We added _NORECLAIM to request that kmem_alloc_contig_pages() not spend time scanning physical memory for candidates to reclaim. In some situations the scanning can induce large amounts of undesirable latency, and it's less important that the request be satisfied than it is that we not spend many milliseconds scanning. The problem extends to vm_reserv_reclaim_contig(), which unlike vm_reserv_reclaim() may have to scan the entire list of partially populated reservations. Use VM_ALLOC_NORECLAIM to request that this scan not be executed.[1] As a side effect, this fixes a regression in 02fb0585e7b3 ("vm_page: Drop handling of VM_ALLOC_NOOBJ in vm_page_alloc_contig_domain()") where VM_ALLOC_CONTIG was not included in VPAC_FLAGS or VPANC_FLAGS even though it is not masked by kmem_alloc_contig_pages().[2] Reported by: gallatin [1], glebius [2] Reviewed by: alc, glebius, kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32899
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 | Various commands and libraries under the GNU Public License. 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.