ccache is mostly beneficial for frequent builds where -DNO_CLEAN is not
used to achieve a safe pseudo-incremental build. This is explained in
more detail upstream [1] [2]. It incurs about a 20%-28% hit to populate the
cache, but with a full cache saves 30-50% in build times. When combined with
the WITH_FAST_DEPEND feature it saves up to 65% since ccache does cache the
resulting dependency file, which it does not do when using mkdep(1)/'CC
-E'. Stats are provided at the end of this message.
This removes the need to modify /etc/make.conf with the CC:= and CXX:=
lines which conflicted with external compiler support [3] (causing the
bootstrap compiler to not be built which lead to obscure failures [4]),
incorrectly invoked ccache in various stages, required CCACHE_CPP2 to avoid
Clang errors with parenthesis, and did not work with META_MODE.
The option name was picked to match the existing option in ports. This
feature is available for both in-src and out-of-src builds that use
/usr/share/mk.
Linking, assembly compiles, and pre-processing avoid using ccache since it is
only overhead. ccache does nothing special in these modes, although there is
no harm in calling it for them.
CCACHE_COMPILERCHECK is set to 'content' when using the in-tree bootstrap
compiler to hash the content of the compiler binary to determine if it
should be a cache miss. For external compilers the 'mtime' option is used
as it is more efficient and likely to be correct. Future work may optimize the
'content' check using the same checks as whether a bootstrap compiler is needed
to be built.
The CCACHE_CPP2 pessimization is currently default in our devel/ccache
port due to Clang requiring it. Clang's -Wparentheses-equality,
-Wtautological-compare, and -Wself-assign warnings do not mix well with
compiling already-pre-processed code that may have expanded macros that
trigger the warnings. GCC has so far not had this issue so it is allowed to
disable the CCACHE_CPP2 default in our port.
Sharing a cache between multiple checkouts, or systems, is explained in
the ccache manual. Sharing a cache over NFS would likely not be worth
it, but syncing cache directories between systems may be useful for an
organization. There is also a memcached backend available [5]. Due to using
an object directory outside of the source directory though you will need to
ensure that both are in the same prefix and all users use the same layout. A
possible working layout is as follows:
Source: /some/prefix/src1
Source: /some/prefix/src2
Source: /some/prefix/src3
Objdir: /some/prefix/obj
Environment: CCACHE_BASEDIR='${SRCTOP:H}' MAKEOBJDIRPREFIX='${SRCTOP:H}/obj'
This will use src*/../obj as the MAKEOBJDIRPREFIX and tells ccache to replace
all absolute paths to be relative. Using something like this is required due
to -I and -o flags containing both SRC and OBJDIR absolute paths that ccache
adds into its hash for the object without CCACHE_BASEDIR.
distcc can be hooked into by setting CCACHE_PREFIX=/usr/local/bin/distcc.
I have not personally tested this and assume it will not mix well with
using the bootstrap compiler.
The cache from buildworld can be reused in a subdir by first running
'make buildenv' (from r290424).
Note that the cache is currently different depending on whether -j is
used or not due to ccache enabling -fdiagnostics-color automatically if
stderr is a TTY, which bmake only does if not using -j.
The system I used for testing was:
WITNESS
Build options: -j20 WITH_LLDB=yes WITH_DEBUG_FILES=yes WITH_CCACHE_BUILD=yes
DISK: ZFS 3-way mirror with very slow disks using SSD l2arc/log.
The arc was fully populated with src tree files and ccache objects.
RAM: 76GiB
CPU: Intel(R) Xeon(R) CPU L5520 @2.27GHz
2 package(s) x 4 core(s) x 2 SMT threads = hw.ncpu=16
The WITH_FAST_DEPEND feature was used for comparison here as well to show
the dramatic time savings with a full cache.
buildworld:
x buildworld-before
+ buildworld-ccache-empty
* buildworld-ccache-full
% buildworld-ccache-full-fastdep
# buildworld-fastdep
+-------------------------------------------------------------------------------+
|% * # +|
|% * # +|
|% * # xxx +|
| |A |
| A|
| A |
|A |
| A |
+-------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 3744.13 3794.31 3752.25 3763.5633 26.935139
+ 3 4519 4525.04 4520.73 4521.59 3.1104823
Difference at 95.0% confidence
758.027 +/- 43.4565
20.1412% +/- 1.15466%
(Student's t, pooled s = 19.1726)
* 3 1823.08 1827.2 1825.62 1825.3 2.0785572
Difference at 95.0% confidence
-1938.26 +/- 43.298
-51.5007% +/- 1.15045%
(Student's t, pooled s = 19.1026)
% 3 1266.96 1279.37 1270.47 1272.2667 6.3971113
Difference at 95.0% confidence
-2491.3 +/- 44.3704
-66.1952% +/- 1.17895%
(Student's t, pooled s = 19.5758)
# 3 3153.34 3155.16 3154.2 3154.2333 0.91045776
Difference at 95.0% confidence
-609.33 +/- 43.1943
-16.1902% +/- 1.1477%
(Student's t, pooled s = 19.0569)
buildkernel:
x buildkernel-before
+ buildkernel-ccache-empty
* buildkernel-ccache-empty-fastdep
% buildkernel-ccache-full
# buildkernel-ccache-full-fastdep
@ buildkernel-fastdep
+-------------------------------------------------------------------------------+
|# @ % * |
|# @ % * x + |
|# @ % * xx ++|
| MA |
| MA|
| A |
| A |
|A |
| A |
+-------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 571.57 573.94 571.79 572.43333 1.3094401
+ 3 727.97 731.91 728.06 729.31333 2.2492295
Difference at 95.0% confidence
156.88 +/- 4.17129
27.4058% +/- 0.728695%
(Student's t, pooled s = 1.84034)
* 3 527.1 528.29 528.08 527.82333 0.63516402
Difference at 95.0% confidence
-44.61 +/- 2.33254
-7.79305% +/- 0.407478%
(Student's t, pooled s = 1.02909)
% 3 400.4 401.05 400.62 400.69 0.3306055
Difference at 95.0% confidence
-171.743 +/- 2.16453
-30.0023% +/- 0.378128%
(Student's t, pooled s = 0.954969)
# 3 201.94 203.34 202.28 202.52 0.73020545
Difference at 95.0% confidence
-369.913 +/- 2.40293
-64.6212% +/- 0.419774%
(Student's t, pooled s = 1.06015)
@ 3 369.12 370.57 369.3 369.66333 0.79033748
Difference at 95.0% confidence
-202.77 +/- 2.45131
-35.4225% +/- 0.428227%
(Student's t, pooled s = 1.0815)
[1] https://ccache.samba.org/performance.html
[2] http://www.mail-archive.com/ccache@lists.samba.org/msg00576.html
[3] https://reviews.freebsd.org/D3484
[5] https://github.com/jrosdahl/ccache/pull/30
PR: 182944 [4]
MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division
Relnotes: yes
This is because the .meta files generated from filemon already contain a
list of all files read to generate the object.
X-MFC-With: r290433
MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division
This is especially noticeable in the kernel obj directory since it
includes so many files.
X-MFC-With: r290433
MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division
This speeds up buildworld by 16% on my system and buildkernel by 35%.
Rather than calling mkdep(1), which is just a wrapper around 'cc -E',
use the modern -MD -MT -MF flags to gather and generate dependencies during
compilation. This flag was introduced in GCC "a long time ago", in GCC 3.0,
and is also supported by Clang. (It appears that ICC also supports this but I
do not have access to test it). This avoids running the preprocessor *twice*
for every build, in both 'make depend' and 'make all'. This is especially
noticeable when using ccache since it does not cache preprocessor results from
mkdep(1) / 'cc -E', but still speeds up compilation with the -MD flags.
For 'make depend' a tree-walk is still done to ensure that all DPSRCS
are generated when expected, and that beforedepend/afterdepend and
_EXTRADEPEND are all still respected. In time this may change but for now
I've been conservative. The time for a tree-walk with -j combined with
SUBDIR_PARALLEL is not significant. For example, it takes about 9 seconds
with -j15 to walk all of src/ for 'make depend' now on my system.
A .depend file is still generated with the various rules that apply to
the final target, or custom rules. Otherwise there are now
per-built-object-file .depend files, such as .depend.filename.o. These
are included directly by make rather than populating .depend with a loop
and .depend lines, which only added overhead to the now almost-NOP 'make
depend' phase.
Before this I experimented with having mkdep(1) called in parallel per-file.
While this improved the kernel and lib/libc 'make depend' phase, it resulted
in slower build times overall.
The -M flags are removed from CFLAGS when linking since they have no effect.
Enabling this by default, for src or out-of-src, can be done once more testing
has been done, such as a ports exp-run, and with more compilers.
The system I used for testing was:
WITNESS
Build options: -j20 WITH_LLDB=yes WITH_DEBUG_FILES=yes WITH_FAST_DEPEND=yes
DISK: ZFS 3-way mirror with very slow disks using SSD l2arc/log.
The arc was fully populated with src tree files.
RAM: 76GiB
CPU: Intel(R) Xeon(R) CPU L5520 @2.27GHz
2 package(s) x 4 core(s) x 2 SMT threads = hw.ncpu=16
buildworld:
x buildworld-before
+ buildworld-fastdep
+-------------------------------------------------------------------------------+
|+ |
|+ |
|+ xx x|
| |_MA___||
|A |
+-------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 3744.13 3794.31 3752.25 3763.5633 26.935139
+ 3 3153.34 3155.16 3154.2 3154.2333 0.91045776
Difference at 95.0% confidence
-609.33 +/- 43.1943
-16.1902% +/- 1.1477%
(Student's t, pooled s = 19.0569)
buildkernel:
x buildkernel-before
+ buildkernel-fastdep
+-------------------------------------------------------------------------------+
|+ x |
|++ xx|
| A||
|A| |
+-------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 3 571.57 573.94 571.79 572.43333 1.3094401
+ 3 369.12 370.57 369.3 369.66333 0.79033748
Difference at 95.0% confidence
-202.77 +/- 2.45131
-35.4225% +/- 0.428227%
(Student's t, pooled s = 1.0815)
Sponsored by: EMC / Isilon Storage Division
MFC after: 3 weeks
Relnotes: yes
an error.
Most of these do a 'mkdir -p' or 'install -d' before installing, but add
the trailing / here for consistency with the userland install.
MFC after: 2 weeks
X-MFC-With: r289391
Sponsored by: EMC / Isilon Storage Division
- 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
This avoids needing a large boot partition / file system in order to
accommodate multiple kernels, and provides consistency with userland
debug. This also simplifies the process of moving kernel debug files
to a separate package and installing them on demand.
In addition, change kernel debug file extension to .debug, to match
userland debug files.
When using the supported kernel installation method the
/usr/lib/debug/boot/kernel directory will be renamed (to kernel.old)
as is done with /boot/kernel.
Developers wishing to maintain the historical behavior of installing
debug files in /boot/kernel/ can set KERN_DEBUGDIR="" in src.conf(5).
Reviewed by: bdrewery, brooks, imp, markj
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1006
root disk. The embedded image is linked into the kernel in the .mfs
section.
Add rules and variables to kern.pre.mk and kern.post.mk that handle the
linking of the image. First objcopy is used to generate an object file.
Then, the object file is linked into the kernel.
Submitted by: Steve Kiernan <stevek@juniper.net>
Reviewed by: brooks@
Obtained from: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D2903
This will require for AArch64 as we dont have modules yet.
Sponsored by: HEIF5
Sponsored by: ARM Ltd.
Differential Revision: https://reviews.freebsd.org/D1997
Make the process of embedding MDROOT images less perilous by
makeing the target that links kernel and embedding the image
depend on the image. This means, if the image doesn't exist you
find out before you try to boot from it and that if you change
the image you don't have to touch some random source file to
cause a rebuild.
Don't hide that we're embedding the image.
the aggressive pattern matching of the :C modifier. I tested build and
install in 2 phases, however with different solutions, resulting in the
breakage. Mea culpa.
The solution is to break out the all: target. This causes a few lines of
code duplication, but now the all: target works as it should, and the
other targets continue to work as they did before.
While I'm here, add a ===> header line to the start of each port build
to make it easier to find/more clear in the logs.
important for those that use -DNO_CLEAN routinely, since it will prevent
installing stale stuff, and even more important when the port is upgraded
to a newer version. When the user doesn't use -DNO_CLEAN, this will create
an infinitesimal amount of extra work, but won't hurt anything.
This is necessary because the ports tree has flags that prevent the ususal
'update the build if newer source files exist' logic from doing what it
would do in the base.
LOCALBASE/bin and sbin to PATH, allowing dependencies to be found;
adding SRC_BASE and OSVERSION to match the new kernel, and putting
the related builds under MAKEOBJDIRPREFIX so that they only need
to be built once per kernel.
In addition to the PR this includes ideas/contributions from crees
and matthew.
PR: ports/161452
Submitted by: Garrett Cooper <yanegomi@gmail.com>
The 'make depend' rules have to use custom -I paths for the special compat
includes for the opensolaris/zfs headers.
This option will pull in the couple of files that are shared with dtrace,
but they appear to correctly use the MODULE_VERSION/MODULE_DEPEND rules
so loader should do the right thing, as should kldload.
Reviewed by: pjd (glanced at)
defined based on WITH/WITHOUT_CTF settings, default is WITHOUT_CTF,
NO_CTF overrides WITH_CTF (used by Makefile.inc1)
- CTFCONVERT_CMD/NORMAL_CTFCONVERT are now defined to empty string
if make(1) can handle empty commands
- CTFCONVERT_CMD=... is a hack (should be defined to empty string instead):
make(1) should be taught to ignore empty commands silently in compat mode
(as it does in !compat mode, GNU make also silently ignores empty commands)
and to skip printing empty commands in !compat mode
- config(8) should generate ${NORMAL_CTFCONVERT} invocation without '@':
this will allow to simplify kern.pre.mk even more and lessen the number
of shell invocations during kernel build when CTF is turned off
- WITH_CTF can now be converted to usual MK_CTF=yes/no infrastructure
Pointy hat to: fjoe [1]
wihtout updating world (good transition aide for -current, but also
allows kernels to be built on -stable the old way too). This likely
should go away around FreeBSD 10.0 or so.
WITH{OUT,}_KERNEL_SYMBOLS (defaulting to WITH). In the fullness of
time, likely around 2020, INSTALL_NODEBUG will be removed. For now,
don't print a warning when using INSTALL_NODEBUG, but that will be
coming soon.
to amd64, i386, and pc98. The headers are installed to /usr/include/x86
during an installworld, and an 'x86' symlink is created for kernel builds
similar to 'machine' so that the headers can be included as <x86/foo.h>.
Reviewed by: imp
are some problems with static executables), make.conf (would also
affect ports which do not use GNU make and do not override the
compile targets) or in the kernel config (via "makeoptions
WITH_CTF=yes").
Additional (related) changes:
- propagate WITH_CTF to module builds
- do not add -g to the linker flags, it's a noop there anyway
(at least according to the man page of ld)
- do not add -g to CFLAGS unconditionally
we need to have a look if it is really needed (IMO not) or if there
is a way to add it only when WITH_CTF is used
Note: ctfconvert / ctfmerge lines will not appear in the build output,
to protect the innocent (those which do not build with WITH_CTF would
see the shell-test and may think WITH_CTF is used).
Reviewed by: imp, jhb, scottl (earlier version)
Discussed on: arch@
to module builds. This avoids having to have the module builds walk up
the tree to find the kernel sources. It also allows a kernel + module
build to succeed when a new level of module subdirectories is added without
requiring that the /usr/share/mk/bsd.kmod.mk file on the machine be patched.
MFC after: 1 week
installing the kernel allows one, like with modules, to override
the default user/group and install as non-su to a temporary
directory to test, create images or seed a tftp dir.
Reviewed by: Andrzej Tobola <ato@iem.pw.edu.pl>
MFC after: 4 weeks
This allows to fix a problem with ARM kernel.bin not having the MFS image
embedded: it is objcopied from the kernel.noheader temporary ELF file, which
was not subject to embedding the MFS image previously.
Reviewed by: imp
Approved by: cognet (mentor)
for those upgrading from 4.x -> 5.x. It is therefore no longer
necessary because it is installed on 5.x and 6.x and one has to
upgrade from 6.x -> current, or at the very least 5.x (although not
supported, it can be made to work).
only now) symbolic links in the kernel compile directory, rather
than relying on config(8) to do this. (The changes to config(8)
will be committed separately.) This is aimed towards making the
config(8) as lightweight as possible.
Idea by: bde (all bugs are mine)
gdb(1) command better, though I must admit it's confusing: these
files have not only [debugging] symbols, but much more than that.
Requested by: obrien
our kernel linker will only load PT_LOAD segments, apparently not.
Instead, produce .dbg objects from .debug objects, and install
them together with non-debug objects, as described in objcopy(1).
Original code by: obrien
Try to make everyone happy: David (to have debug kernels installed
by default), Warner (to be able to override that), and myself (for
actually making it all work and to be consistent).
Now, if kernel was configured for debugging (through DEBUG=-g in
the kernel config file or "config -g"), doing "make install" will
install debug versions of kernel and module objects with their
canonical names,
kernel.debug -> /boot/kernel/kernel
if_fxp.ko.debug -> /boot/kernel/if_fxp.ko
Installing a kernel not configured for debugging, or debug kernel
with INSTALL_NODEBUG variable defined, will install non-debug
kernel and module objects.
Also, restore the install.debug and reinstall.debug targets that
are part of the existing API (they cause some additional gdb(1)
scripts to be installed).
