Unmapped mbufs allow sendfile to carry multiple pages of data in a
single mbuf, without mapping those pages. It is a requirement for
Netflix's in-kernel TLS, and provides a 5-10% CPU savings on heavy web
serving workloads when used by sendfile, due to effectively
compressing socket buffers by an order of magnitude, and hence
reducing cache misses.
For this new external mbuf buffer type (EXT_PGS), the ext_buf pointer
now points to a struct mbuf_ext_pgs structure instead of a data
buffer. This structure contains an array of physical addresses (this
reduces cache misses compared to an earlier version that stored an
array of vm_page_t pointers). It also stores additional fields needed
for in-kernel TLS such as the TLS header and trailer data that are
currently unused. To more easily detect these mbufs, the M_NOMAP flag
is set in m_flags in addition to M_EXT.
Various functions like m_copydata() have been updated to safely access
packet contents (using uiomove_fromphys()), to make things like BPF
safe.
NIC drivers advertise support for unmapped mbufs on transmit via a new
IFCAP_NOMAP capability. This capability can be toggled via the new
'nomap' and '-nomap' ifconfig(8) commands. For NIC drivers that only
transmit packet contents via DMA and use bus_dma, adding the
capability to if_capabilities and if_capenable should be all that is
required.
If a NIC does not support unmapped mbufs, they are converted to a
chain of mapped mbufs (using sf_bufs to provide the mapping) in
ip_output or ip6_output. If an unmapped mbuf requires software
checksums, it is also converted to a chain of mapped mbufs before
computing the checksum.
Submitted by: gallatin (earlier version)
Reviewed by: gallatin, hselasky, rrs
Discussed with: ae, kp (firewalls)
Relnotes: yes
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20616
-Wformat-zero-length does not highlight any particularly wrong code and it
is especially meaningless for device_printf(). Turn it off entirely to
remove a source of false positives.
Sponsored by: Dell EMC Isilon
add gcov support and export results as files in debugfs
Reviewed by: hps@
MFC after: 1 week
Sponsored by: iX Systems
Differential Revision: https://reviews.freebsd.org/D19260
This fixes a warning seen when compiling amd64 GENERIC with clang 7.
Also remove the workaround added in r337324. clang 7 and gcc 4.2
generate the same code with or without the code change.
Reviewed by: imp (previous version)
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D18603
CLANG_NO_IAS34 was introduced in r276696 to allow then-HEAD kernels to
be built with clang 3.4 in FreeBSD 10. As FreeBSD 11 and later includes
a version of Clang with a sufficiently capable integrated assembler we
do not need the workaround any longer.
Sponsored by: The FreeBSD Foundation
This was disabled recently due to lack of support in KDB disassembler
and DTrace FBT provider. Support for 'C'-extension to both of these was
added, so we can now enable 'C'-extension.
This reduces size of the kernel important for low-end embedded devices,
and saves cache footprint for high perfomance machines.
Approved by: re (kib)
Sponsored by: DARPA, AFRL
It works excellent, but KDB disassembler and DTrace FBT provider for
RISC-V do lack support for it. They currently handle 4-byte instructions
only, while C-compressed ISA extension introduces 2-byte instructions
freely mixing them together.
So disable it for now.
Reviewed by: markj@
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D16436
Remove all the big-endian arm architectures (ixp425 and ixp435)
support in the kernel and associated drivers.
Differential Revision: https://reviews.freebsd.org/D16257
We can't modify vendor code so there's no signal in warnings from it.
Similarly -Waddress-of-packed-member is not useful on networking code
as access to packed structures is fundamental to its operation.
Retpoline is a compiler-based mitigation for CVE-2017-5715, also known
as Spectre V2, that protects against speculative execution branch target
injection attacks.
In this commit it is disabled by default, but will be changed in a
followup commit.
Reviewed by: bdrewery (previous version)
MFC after: 3 days
Security: CVE-2017-5715
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D14242
This has the same effects on DDB working as -mcall=aixdesc, but also is
supported by clang and marginally improves kernel performance.
MFC after: 2 weeks
Instead, use a runtime decision to handle COP1 traps. If floating point
support is present in the current CPU, enable saving of the floating point
state. If support is not present, fail with SIGILL.
Reviewed by: imp, br
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D12707
Make armv7 as a new MACHINE_ARCH.
Copy all the places we do armv6 and add armv7 as basically an
alias. clang appears to generate code for armv7 by default. armv7 hard
float isn't supported by the the in-tree gcc, so it hasn't been
updated to have a new default.
Support armv7 as a new valid MACHINE_ARCH (and by extension
TARGET_ARCH).
Add armv7 to the universe build.
Differential Revision: https://reviews.freebsd.org/D12010
New version is not compatible on supervisor mode with v1.9.1
(previous version).
Highlights:
o BBL (Berkeley Boot Loader) provides no initial page tables
anymore allowing us to choose VM, to build page tables manually
and enable MMU in S-mode.
o SBI interface changed.
o GENERIC kernel.
FDT is now chosen standard for RISC-V hardware description.
DTB is now provided by Spike (golden model simulator). This
allows us to introduce GENERIC kernel. However, description
for console and timer devices is not provided in DTB, so move
these devices temporary to nexus bus.
o Supervisor can't access userspace by default. Solution is to
set SUM (permit Supervisor User Memory access) bit in sstatus
register.
o Compressed extension is now turned on by default.
o External GCC 7.1 compiler used.
o _gp renamed to __global_pointer$
o Compiler -march= string is now in use allowing us to choose
required extensions (compressed, FPU, atomic, etc).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11800
Previously the linker emulation was only passed when building binary
objects for firmware modules. This change always passes the desired
output format for kernel modules and kernels rather than requiring the
toolchain's default output format to match the desired output format.
This in turn permits use of external toolchains whose default output
format does not match the desired output format.
Reviewed by: imp, emaste
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D10085
* Clang/llvm does not (yet) support -m(no-)spe, so make it gcc-only
* Clang now supports -msoft-float, and does not appear to recognize
"-disable-ppc-float-in-variadic", which appears to have been a crutch until
soft-float was implemented. It's now implemented for both 32- and 64-bit.
* Clang/llvm use a 'medium' code model by default for powerpc64, supporting up
to 4GB TOC, and does not support the '-mminimal-toc' option. Given both of
these, make -mminimal-toc gcc-only.
MFC after: 2 weeks
Recognize new MACHINE_ARCH names now as we have added hardfloat support.
Switch JZ4780 to mipselhf and remove all uses of TARGET_ARCH in kernel
.mk files.
Reviewed by: adrian
Differential Revision: https://reviews.freebsd.org/D8989
Summary:
The Freescale e500v2 PowerPC core does not use a standard FPU.
Instead, it uses a Signal Processing Engine (SPE)--a DSP-style vector processor
unit, which doubles as a FPU. The PowerPC SPE ABI is incompatible with the
stock powerpc ABI, so a new MACHINE_ARCH was created to deal with this.
Additionaly, the SPE opcodes overlap with Altivec, so these are mutually
exclusive. Taking advantage of this fact, a new file, powerpc/booke/spe.c, was
created with the same function set as in powerpc/powerpc/altivec.c, so it
becomes effectively a drop-in replacement. setjmp/longjmp were modified to save
the upper 32-bits of the now-64-bit GPRs (upper 32-bits are only accessible by
the SPE).
Note: This does _not_ support the SPE in the e500v1, as the e500v1 SPE does not
support double-precision floating point.
Also, without a new MACHINE_ARCH it would be impossible to provide binary
packages which utilize the SPE.
Additionally, no work has been done to support ports, work is needed for this.
This also means no newer gcc can yet be used. However, gcc's powerpc support
has been refactored which would make adding a powerpcspe-freebsd target very
easy.
Test Plan:
This was lightly tested on a RouterBoard RB800 and an AmigaOne A1222
(P1022-based) board, compiled against the new ABI. Base system utilities
(/bin/sh, /bin/ls, etc) still function appropriately, the system is able to boot
multiuser.
Reviewed By: bdrewery, imp
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D5683
This is in preparation for linking with LLVM's lld, which does not have
a compiled-in default output emulation. lld requires that it is
specified via the -m option, or obtained from the object file(s) being
linked.
This will also allow all build targets to share a common linker binary.
Reviewed by: imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7837
lang/gcc{48,49,5} lacks -fformat-extensions support (causing build errors, which
is what prompted r302403 to be committed). devel/amd64-gcc on the other hand
(which is used by Jenkins), has the support.
This fixes the Jenkins failure emails due to excessive warnings being produced
with "make buildkernel".
Discussed with: lwhsu
Reported by: Jenkins (FreeBSD_HEAD_amd64_gcc job)
Sponsored by: EMC / Isilon Storage Division
Ports versions of gcc do not have -fformat-extensions support.
This unbreaks compiling the kernel/modules with non-base gcc (4.8,
5.0, etc) if MK_FORMAT_EXTENSIONS=yes (the default).
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D7150
Reviewed by: bdrewery
Sponsored by: EMC / Isilon Storage Division
This is the final step required allowing to compile and to run RISC-V
kernel and userland from HEAD.
RISC-V is a completely open ISA that is freely available to academia
and industry.
Thanks to all the people involved! Special thanks to Andrew Turner,
David Chisnall, Ed Maste, Konstantin Belousov, John Baldwin and
Arun Thomas for their help.
Thanks to Robert Watson for organizing this project.
This project sponsored by UK Higher Education Innovation Fund (HEIF5) and
DARPA CTSRD project at the University of Cambridge Computer Laboratory.
FreeBSD/RISC-V project home: https://wiki.freebsd.org/riscv
Reviewed by: andrew, emaste, kib
Relnotes: Yes
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D4982
- Move the required kernel compiler flags from Makefile.arm64 to kern.mk.
- Build arm64 modules as PIC; non-PIC relocations in .o for shared object
output cannot be handled.
- Do not try to install aarch64 symlink.
- A hack for arm64 to avoid ld -r stage. See the comment for the explanation.
Some functionality is lost, like ctf handling, but hopefully will be
restored after newer linker is available.
Reviewed by: andrew, emaste
Tested by: andrew (on real hardware)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3796
