From: Michał Górny <mgorny@gentoo.org>
Date: Thu, 18 Jan 2018 21:23:13 +0000 (+0100)
Subject: sys-libs/libomp: List broken PDS scheduler versions
X-Git-Url: http://git.tremily.us/gitweb.cgi?a=commitdiff_plain;h=a4d33e643f3aa8cb5cf8b0555328e846e4f6f9de;p=gentoo.git

sys-libs/libomp: List broken PDS scheduler versions

The sched_yield() call has been reintroduced in PDS 0.98i. Improve
the kernel check to explicitly list which PDS versions are affected,
and which -pf kernels are affected (sadly, no fixed version yet).
Big thanks to Holger Hoffstätte for convincing upstream to fix this
and all the research!

Bug: https://bugs.gentoo.org/638410
---

diff --git a/sys-libs/libomp/libomp-4.0.1.ebuild b/sys-libs/libomp/libomp-4.0.1.ebuild
index 299e49921e10..920d364c8a85 100644
--- a/sys-libs/libomp/libomp-4.0.1.ebuild
+++ b/sys-libs/libomp/libomp-4.0.1.ebuild
@@ -43,7 +43,10 @@ S=${WORKDIR}/openmp-${PV/_/}.src
 CMAKE_BUILD_TYPE=RelWithDebInfo
 
 CONFIG_CHECK="~!SCHED_PDS"
-ERROR_SCHED_PDS="PDS scheduler is not supported as it does not implement sched_yield()"
+ERROR_SCHED_PDS="PDS scheduler versions >= 0.98c < 0.98i (e.g. used in kernels
+>= 4.13-pf11, no fixed release yet) do not implement sched_yield() call which
+may result in horrible performance problems with libomp. If you are using one
+of the specified kernel versions, you may want to disable the PDS scheduler."
 
 python_check_deps() {
 	has_version "dev-python/lit[${PYTHON_USEDEP}]"
diff --git a/sys-libs/libomp/libomp-5.0.1.ebuild b/sys-libs/libomp/libomp-5.0.1.ebuild
index e53670dab6d4..9075688c9e49 100644
--- a/sys-libs/libomp/libomp-5.0.1.ebuild
+++ b/sys-libs/libomp/libomp-5.0.1.ebuild
@@ -43,7 +43,10 @@ S=${WORKDIR}/openmp-${PV/_/}.src
 CMAKE_BUILD_TYPE=RelWithDebInfo
 
 CONFIG_CHECK="~!SCHED_PDS"
-ERROR_SCHED_PDS="PDS scheduler is not supported as it does not implement sched_yield()"
+ERROR_SCHED_PDS="PDS scheduler versions >= 0.98c < 0.98i (e.g. used in kernels
+>= 4.13-pf11, no fixed release yet) do not implement sched_yield() call which
+may result in horrible performance problems with libomp. If you are using one
+of the specified kernel versions, you may want to disable the PDS scheduler."
 
 python_check_deps() {
 	has_version "dev-python/lit[${PYTHON_USEDEP}]"
diff --git a/sys-libs/libomp/libomp-6.0.9999.ebuild b/sys-libs/libomp/libomp-6.0.9999.ebuild
index 461064323a15..5e156aca296c 100644
--- a/sys-libs/libomp/libomp-6.0.9999.ebuild
+++ b/sys-libs/libomp/libomp-6.0.9999.ebuild
@@ -44,7 +44,10 @@ DEPEND="${RDEPEND}
 CMAKE_BUILD_TYPE=RelWithDebInfo
 
 CONFIG_CHECK="~!SCHED_PDS"
-ERROR_SCHED_PDS="PDS scheduler is not supported as it does not implement sched_yield()"
+ERROR_SCHED_PDS="PDS scheduler versions >= 0.98c < 0.98i (e.g. used in kernels
+>= 4.13-pf11, no fixed release yet) do not implement sched_yield() call which
+may result in horrible performance problems with libomp. If you are using one
+of the specified kernel versions, you may want to disable the PDS scheduler."
 
 python_check_deps() {
 	has_version "dev-python/lit[${PYTHON_USEDEP}]"
diff --git a/sys-libs/libomp/libomp-9999.ebuild b/sys-libs/libomp/libomp-9999.ebuild
index 630a7bf4f050..ad6d62ae7449 100644
--- a/sys-libs/libomp/libomp-9999.ebuild
+++ b/sys-libs/libomp/libomp-9999.ebuild
@@ -43,7 +43,10 @@ DEPEND="${RDEPEND}
 CMAKE_BUILD_TYPE=RelWithDebInfo
 
 CONFIG_CHECK="~!SCHED_PDS"
-ERROR_SCHED_PDS="PDS scheduler is not supported as it does not implement sched_yield()"
+ERROR_SCHED_PDS="PDS scheduler versions >= 0.98c < 0.98i (e.g. used in kernels
+>= 4.13-pf11, no fixed release yet) do not implement sched_yield() call which
+may result in horrible performance problems with libomp. If you are using one
+of the specified kernel versions, you may want to disable the PDS scheduler."
 
 python_check_deps() {
 	has_version "dev-python/lit[${PYTHON_USEDEP}]"