freebsd-src/sys
Alan Cox 268f19aacc vm: Reduce address space fragmentation
jemalloc performs two types of virtual memory allocations: (1) large
chunks of virtual memory, where the chunk size is a multiple of a
superpage and explicitly aligned, and (2) small allocations, mostly
128KB, where no alignment is requested.  Typically, it starts with a
small allocation, and over time it makes both types of allocation.

With anon_loc being updated on every allocation, we wind up with a
repeating pattern of a small allocation, a large gap, and a large,
aligned allocation.  (As an aside, we wind up allocating a reservation
for these small allocations, but it will never fill because the next
large, aligned allocation updates anon_loc, leaving a gap that will
never be filled with other small allocations.)

With this change, anon_loc isn't updated on every allocation.  So, the
small allocations will be clustered together, the large allocations will
be clustered together, and there will be fewer gaps between the
anonymous memory allocations.  In addition, I see a small reduction in
reservations allocated (e.g., 1.6% during buildworld), fewer partially
populated reservations, and a small increase in 64KB page promotions on
arm64.

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D39845
2024-06-13 15:13:45 -05:00
..
amd64 rangeset: add next() iteration 2024-06-06 13:42:31 -05:00
arm Remove the arm FIQ support 2024-06-10 15:16:10 +00:00
arm64 arm64: Create a version of vfp_save_state for cpu_switch 2024-06-12 14:09:14 +01:00
bsm
cam ctladm: don't require the use of "-p" with "port -r" 2024-06-10 10:01:25 -06:00
cddl arm64: Support BTI checking in most of the kernel 2024-06-05 09:23:40 +00:00
compat LinuxKPI: 802.11: use net80211 IEEE80211_HTCAP_* definitions 2024-06-07 23:57:04 +00:00
conf Remove the arm FIQ support 2024-06-10 15:16:10 +00:00
contrib openzfs: Fix mismerge breaking macOS bootstrap 2024-05-31 22:12:18 +01:00
crypto
ddb
dev powerof2: replace loops with fls or ilog2 2024-06-12 05:00:48 -05:00
dts dts: Bump the freebsd branding version to 6.8 2024-05-06 10:47:26 +02:00
fs nfscl: Add support for read delegations and atomic upgrade 2024-06-12 16:41:12 -07:00
gdb sys/gdb: Support hardware breakpoints 2024-04-12 09:32:55 +00:00
geom geom_io: Shift to pause_sbt to eliminate bogus min and update comment. 2024-05-24 08:31:55 -06:00
gnu
i386 pmap: Skip some superpage promotion attempts that will fail 2024-06-04 00:38:05 -05:00
isa
kern subr_rangeset: use pctrie_reclaim_cb in remove_all 2024-06-13 13:52:25 -05:00
kgssapi
libkern
modules vmm: Only link the arm64 hyp code in vmm.ko once 2024-06-10 15:16:10 +00:00
net pf: convert DIOCBEGINADDRS to netlink 2024-06-08 04:46:43 +02:00
net80211 net80211: fix IEEE80211_FHT_BITS 2024-06-07 21:15:04 +00:00
netgraph netgraph: provide separate malloc type for nodes that are missing it 2024-05-31 09:19:54 -07:00
netinet pf: simplify pf_addrcpy() and pf_match_addr() 2024-06-06 15:45:31 +02:00
netinet6 in6_rmx: remove unnecessary socketvar.h 2024-05-07 14:15:56 -07:00
netipsec
netlink netlink: pass the correct arguments for SIOCDIFADDR and SIOCDIFADDR_IN6 2024-06-06 15:45:30 +02:00
netpfil pf: make TCP sequence number tracking less strict by one octet for FIN packets 2024-06-12 23:33:11 +02:00
netsmb
nfs
nfsclient
nfsserver
nlm
ofed ibcore: Mark write-only variables 2024-06-12 14:04:45 +01:00
opencrypto
powerpc pmap: Skip some superpage promotion attempts that will fail 2024-06-04 00:38:05 -05:00
riscv riscv: include ahci device to GENERIC. 2024-06-12 13:40:50 +01:00
rpc svc.c: Check for a non-NULL xp_socket 2024-05-27 19:22:04 -07:00
security MAC/do: allow to call setuid if real user id is 0 2024-05-23 12:09:11 +02:00
sys subr_pctrie: add leaf callbacks to pctrie_reclaim 2024-06-13 11:48:09 -05:00
teken teken: fix style in teken_wcwidth.h 2023-10-13 08:14:57 +03:00
tests callout: retire callout_async_drain() 2024-01-24 09:33:27 -08:00
tools
ufs uio: Use switch statements when handling UIO_READ vs UIO_WRITE 2024-05-10 13:43:36 -07:00
vm vm: Reduce address space fragmentation 2024-06-13 15:13:45 -05:00
x86 x86: simplify ceil(log2(x)) function 2024-06-04 13:00:25 -05:00
xdr
xen
Makefile
README.md

FreeBSD Kernel Source:

This directory contains the source files and build glue that make up the FreeBSD kernel and its modules, including both original and contributed software.

Kernel configuration files are located in the conf/ subdirectory of each architecture. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. LINT is a compile-only configuration used to maximize build coverage and detect regressions.

Documentation:

Source code documentation is maintained in a set of man pages, under section 9. These pages are located in share/man/man9, from the top-level of the src tree. Consult intro(9) for an overview of existing pages.

Some additional high-level documentation of the kernel is maintained in the Architecture Handbook.

Source Roadmap:

Directory Description
amd64 AMD64 (64-bit x86) architecture support
arm 32-bit ARM architecture support
arm64 64-bit ARM (AArch64) architecture support
cam Common Access Method storage subsystem - cam(4) and ctl(4)
cddl CDDL-licensed optional sources such as DTrace
conf kernel build glue
compat Linux compatibility layer, FreeBSD 32-bit compatibility
contrib 3rd-party imported software such as OpenZFS
crypto crypto drivers
ddb interactive kernel debugger - ddb(4)
fs most filesystems, excluding UFS, NFS, and ZFS
dev device drivers and other arch independent code
gdb kernel remote GDB stub - gdb(4)
geom GEOM framework - geom(4)
i386 i386 (32-bit x86) architecture support
kern main part of the kernel
libkern libc-like and other support functions for kernel use
modules kernel module infrastructure
net core networking code
net80211 wireless networking (IEEE 802.11) - net80211(4)
netgraph graph-based networking subsystem - netgraph(4)
netinet IPv4 protocol implementation - inet(4)
netinet6 IPv6 protocol implementation - inet6(4)
netipsec IPsec protocol implementation - ipsec(4)
netpfil packet filters - ipfw(4), pf(4), and ipfilter(4)
opencrypto OpenCrypto framework - crypto(7)
powerpc PowerPC/POWER (32 and 64-bit) architecture support
riscv 64-bit RISC-V architecture support
security security facilities - audit(4) and mac(4)
sys kernel headers
tests kernel unit tests
ufs Unix File System - ffs(7)
vm virtual memory system
x86 code shared by AMD64 and i386 architectures