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Matt Macy acf50a7f68 hwpmc: limit wait for user callchain collection to 1 tick
The hwpmc pcpu sample buffer is prone to head of line blocking
when waiting for user process to return to user space and
collect a pending callchain. If more than one tick has elapsed
between the time the sample entry was marked for collection and
the time that the hardclock pmc handler runs to copy the records
to a larger temporary buffer, mark the sample entry as not in
use.

This changes reduces the number of samples marked as not valid
when collecting under load from ~99.5% to 5-20%.

Reported by:	mjg@
MFC after:	3 days
2018-11-05 08:11:16 +00:00
bin capsicum: use a new capsicum helpers in tools 2018-11-04 19:24:49 +00:00
cddl dtrace(1): remove reference to dtruss that was removed from base 2018-10-31 15:29:26 +00:00
contrib Un-break build libexpact. 2018-11-04 18:24:11 +00:00
crypto Update SHLIB_VERSION_NUMBER following the OpenSSL shared library 2018-10-25 18:46:45 +00:00
etc Simplify NLS alias handling by using native make(1) multi variable for loops 2018-11-04 10:14:08 +00:00
gnu Implement a BSD licensed crtbegin/crtend 2018-10-25 17:39:41 +00:00
include
kerberos5
lib Move pmc* bits behind MK_PMC to fix WITHOUT_PMC build 2018-11-05 00:20:58 +00:00
libexec rtld: move relro enforcement after ifunc processing 2018-11-04 19:21:12 +00:00
release Pass _BRANCH in the reldoc target to ensure the correct 2018-10-29 21:03:43 +00:00
rescue rescue: Add bectl(8) 2018-10-31 20:42:18 +00:00
sbin ping: simplify use of Casper 2018-11-04 20:26:29 +00:00
secure Bump base OpenSSL libraries versions to avoid conflict with port's libraries. 2018-10-25 13:37:57 +00:00
share Add hybrid C.UTF-8 locale being identical to default C locale except 2018-11-04 22:13:22 +00:00
stand loader: biosdisk should check if the media is present 2018-11-02 11:41:58 +00:00
sys hwpmc: limit wait for user callchain collection to 1 tick 2018-11-05 08:11:16 +00:00
targets Add -b/-l options to localedef(1) to specify output endianness and use 2018-10-20 20:51:05 +00:00
tests Vendor import of expat 2.2.6 2018-11-02 22:10:07 +00:00
tools Add hybrid C.UTF-8 locale being identical to default C locale except 2018-11-04 22:13:22 +00:00
usr.bin capsicum: use a new capsicum helpers in tools 2018-11-04 19:24:49 +00:00
usr.sbin Move pmc* bits behind MK_PMC to fix WITHOUT_PMC build 2018-11-05 00:20:58 +00:00
.arcconfig
.arclint
.gitattributes
.gitignore
COPYRIGHT
LOCKS
MAINTAINERS
Makefile
Makefile.inc1 Avoid binutils test in cleandir/obj stages 2018-10-31 18:08:12 +00:00
Makefile.libcompat libcompat: disable retpoline when building build tools 2018-11-03 19:31:11 +00:00
Makefile.sys.inc
ObsoleteFiles.inc Add malloc_domainset(9) and _domainset variants to other allocator KPIs. 2018-10-30 18:26:34 +00:00
README Vendor import of expat 2.2.6 2018-11-02 22:10:07 +00:00
README.md Vendor import of expat 2.2.6 2018-11-02 22:10:07 +00:00
UPDATING Add updating entry for DRM 2018-10-20 19:14:46 +00:00

FreeBSD Source:

This is the top level of the FreeBSD source directory. This file was last revised on: FreeBSD

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), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.

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cddl		Various commands and libraries under the Common Development
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contrib		Packages contributed by 3rd parties.

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etc		Template files for /etc.

gnu		Various commands and libraries under the GNU Public License.
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include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

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rescue		Build system for statically linked /rescue utilities.

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stand		Boot loader sources.

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tests		Regression tests which can be run by Kyua.  See tests/README
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