This always has the same meaning in packages - build in annotations to
help
with e.g. custom memory allocators to reduce noise and improve
Valgrind's accuracy.
All invalid uses of this were already fixed (cases where it was used
to control
running the testsuite under Valgrind which we don't want to do, it's
too flaky
under sandbox & not reliable with diff arches.)
Signed-off-by: Sam James <sam@gentoo.org>
---
profiles/use.desc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/profiles/use.desc b/profiles/use.desc
index 04ca8e845ccd9..675fd291fee22 100644
--- a/profiles/use.desc
+++ b/profiles/use.desc
@@ -1,4 +1,4 @@
-# Copyright 1999-2022 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
# Keep them sorted
@@ -333,6 +333,7 @@ usb - Add USB support to applications that have
optional USB support (e.g. cups)
v4l - Enable support for video4linux (using linux-headers or
userspace libv4l libraries)
vaapi - Enable Video Acceleration API for hardware decoding
vala - Enable bindings for dev-lang/vala
+valgrind - Enable annotations for accuracy. May slow down runtime
slightly. Safe to use even if not currently using dev-util/valgrind
vanilla - Do not add extra patches which change default behaviour; DO
NOT USE THIS ON A GLOBAL SCALE as the severity of the meaning changes drastically
vcd - Video CD support
vdpau - Enable the Video Decode and Presentation API for Unix
acceleration interface
This always has the same meaning in packages - build in annotations to help with e.g. custom memory allocators to reduce noise and improve Valgrind's accuracy.
All invalid uses of this were already fixed (cases where it was used to control
running the testsuite under Valgrind which we don't want to do, it's too flaky
under sandbox & not reliable with diff arches.)
Signed-off-by: Sam James <sam@gentoo.org>
---
profiles/use.desc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/profiles/use.desc b/profiles/use.desc
index 04ca8e845ccd9..675fd291fee22 100644
--- a/profiles/use.desc
+++ b/profiles/use.desc
@@ -1,4 +1,4 @@
-# Copyright 1999-2022 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
# Keep them sorted
@@ -333,6 +333,7 @@ usb - Add USB support to applications that have optional USB support (e.g. cups)
v4l - Enable support for video4linux (using linux-headers or userspace libv4l libraries)
vaapi - Enable Video Acceleration API for hardware decoding
vala - Enable bindings for dev-lang/vala
+valgrind - Enable annotations for accuracy. May slow down runtime
slightly. Safe to use even if not currently using dev-util/valgrind
vanilla - Do not add extra patches which change default behaviour; DO NOT USE
THIS ON A GLOBAL SCALE as the severity of the meaning changes drastically
vcd - Video CD support
vdpau - Enable the Video Decode and Presentation API for Unix acceleration interface
Does enabling USE=valgrind impact runtime performance in any way?
Alexe Stefan <stefanalexe48@gmail.com> writes:
Does enabling USE=valgrind impact runtime performance in any way?
A very small amount because it adds a check at runtime for whether
the application is running under Valgrind. The compiler may be able
to optimise this a bit if it can determine it's unlikely (if the
Valgrind headers don't already do this, they should probably mark
them as cold functions).
Sam James <sam@gentoo.org> writes:
This always has the same meaning in packages - build in annotations tohelp
with e.g. custom memory allocators to reduce noise and improveValgrind's accuracy.
All invalid uses of this were already fixed (cases where it was used tocontrol
running the testsuite under Valgrind which we don't want to do, it's tooflaky
under sandbox & not reliable with diff arches.)
LGTM. thanks!
Signed-off-by: Sam James <sam@gentoo.org>
---
profiles/use.desc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/profiles/use.desc b/profiles/use.desc
index 04ca8e845ccd9..675fd291fee22 100644
--- a/profiles/use.desc
+++ b/profiles/use.desc
@@ -1,4 +1,4 @@
-# Copyright 1999-2022 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
# Keep them sortedoptional USB support (e.g. cups)
@@ -333,6 +333,7 @@ usb - Add USB support to applications that have
v4l - Enable support for video4linux (using linux-headers or userspacelibv4l libraries)
vaapi - Enable Video Acceleration API for hardware decodingNOT USE
vala - Enable bindings for dev-lang/vala
+valgrind - Enable annotations for accuracy. May slow down runtime slightly. Safe to use even if not currently using dev-util/valgrind
vanilla - Do not add extra patches which change default behaviour; DO
THIS ON A GLOBAL SCALE as the severity of the meaning changes drasticallyacceleration interface
vcd - Video CD support
vdpau - Enable the Video Decode and Presentation API for Unix
--
Arsen Arsenović
[[PGP Signed Part:Undecided]]
Sam James <sam@gentoo.org> writes:
Alexe Stefan <stefanalexe48@gmail.com> writes:
Does enabling USE=valgrind impact runtime performance in any way?
A very small amount because it adds a check at runtime for whether
the application is running under Valgrind. The compiler may be able
to optimise this a bit if it can determine it's unlikely (if the
Valgrind headers don't already do this, they should probably mark
them as cold functions).
Sorry, I should say, they're hot functions but the if()s for them
should be unlikely()'d.
Sam James <sam@gentoo.org> writes:
[[PGP Signed Part:Undecided]]
Sam James <sam@gentoo.org> writes:
Alexe Stefan <stefanalexe48@gmail.com> writes:
Does enabling USE=valgrind impact runtime performance in any way?
A very small amount because it adds a check at runtime for whether
the application is running under Valgrind. The compiler may be able
to optimise this a bit if it can determine it's unlikely (if the
Valgrind headers don't already do this, they should probably mark
them as cold functions).
Sorry, I should say, they're hot functions but the if()s for them
should be unlikely()'d.
Alexander Monakov reached out and pointed out this isn't right - they're actually branchless and just encoded in nops, so there's really
essentially no runtime cost.
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>Sam James <<a href="mailto:sam@gentoo.org" target="_blank" rel="noreferrer">sam@gentoo.org</a>> writes:<br>
In that case, is it worth it to enable USE=valgrind globally?
Alexe Stefan <stefanalexe48@gmail.com> writes:
In that case, is it worth it to enable USE=valgrind globally?
I have, and I'd say others interested in using Valgrind should too.
</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>Alexe Stefan <<a href="mailto:stefanalexe48@gmail.com" target="_blank" rel="noreferrer">stefanalexe48@gmail.com</a>> writes:<br>
So it's only useful for developers that already use valgrind.
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