[FFmpeg-cvslog] configure: speed up check_deps()
Avi Halachmi (:avih)
git at videolan.org
Mon Aug 27 17:36:25 EEST 2018
ffmpeg | branch: master | Avi Halachmi (:avih) <avihpit at yahoo.com> | Sun Aug 5 06:16:44 2018 +0300| [45499e557c808f43175524a98901efeca715813e] | committer: James Almer
configure: speed up check_deps()
x4 - x25 faster.
check_deps() recursively enables/disables components, and its loop is
iterated nearly 6000 times. It's particularly slow in bash - currently
consuming more than 50% of configure runtime, and about 20% with other
shells.
This commit applies few local optimizations, most effective first:
- Use $1 $2 ... instead of pushvar/popvar, and same at enable_deep*
- Abort early in one notable case - empty deps, to avoid costly no-op.
- Smaller changes which do add up:
- Handle ${cfg}_checking locally instead of via enable[d]/disable
- ${cfg}_checking: test done before inprogress - x2 faster in 50%+
- one eval instead of several at the empty-deps early abort path.
- The "actual work" part is unmodified - just its surroundings.
Biggest speedups (relative and absolute) are observed with bash.
Tested-by: Michael Niedermayer <michael at niedermayer.cc>
Tested-by: Helmut K. C. Tessarek <tessarek at evermeet.cx>
Tested-by: Dave Yeo <daveryeo at telus.net>
Tested-by: Reino Wijnsma <rwijnsma at xs4all.nl>
Signed-off-by: James Almer <jamrial at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=45499e557c808f43175524a98901efeca715813e
---
configure | 86 ++++++++++++++++++++++++++++++++++-----------------------------
1 file changed, 46 insertions(+), 40 deletions(-)
diff --git a/configure b/configure
index 2f2c2dc58c..ba123eadc0 100755
--- a/configure
+++ b/configure
@@ -676,13 +676,10 @@ disable_sanitized(){
do_enable_deep(){
for var; do
enabled $var && continue
- eval sel="\$${var}_select"
- eval sgs="\$${var}_suggest"
- pushvar var sgs
- enable_deep $sel
- popvar sgs
- enable_deep_weak $sgs
- popvar var
+ set -- $var
+ eval enable_deep \$${var}_select
+ var=$1
+ eval enable_deep_weak \$${var}_suggest
done
}
@@ -694,9 +691,9 @@ enable_deep(){
enable_deep_weak(){
for var; do
disabled $var && continue
- pushvar var
+ set -- $var
do_enable_deep $var
- popvar var
+ var=$1
enable_weak $var
done
}
@@ -756,40 +753,49 @@ is_in(){
return 1
}
+# The cfg loop is very hot (several thousands iterations), and in bash also
+# potentialy quite slow. Try to abort the iterations early, preferably without
+# calling functions. 70%+ of the time cfg is already done or without deps.
check_deps(){
for cfg; do
- enabled ${cfg}_checking && die "Circular dependency for $cfg."
- disabled ${cfg}_checking && continue
- enable ${cfg}_checking
-
- eval dep_all="\$${cfg}_deps"
- eval dep_any="\$${cfg}_deps_any"
- eval dep_con="\$${cfg}_conflict"
- eval dep_sel="\$${cfg}_select"
- eval dep_sgs="\$${cfg}_suggest"
- eval dep_ifa="\$${cfg}_if"
- eval dep_ifn="\$${cfg}_if_any"
-
- pushvar cfg dep_all dep_any dep_con dep_sel dep_sgs dep_ifa dep_ifn
- check_deps $dep_all $dep_any $dep_con $dep_sel $dep_sgs $dep_ifa $dep_ifn
- popvar cfg dep_all dep_any dep_con dep_sel dep_sgs dep_ifa dep_ifn
-
- [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
- [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
- enabled_all $dep_all || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but not all dependencies are satisfied: $dep_all"; }
- enabled_any $dep_any || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but not any dependency is satisfied: $dep_any"; }
- disabled_all $dep_con || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but some conflicting dependencies are unsatisfied: $dep_con"; }
- disabled_any $dep_sel && { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but some selected dependency is unsatisfied: $dep_sel"; }
-
- enabled $cfg && enable_deep_weak $dep_sel $dep_sgs
-
- for dep in $dep_all $dep_any $dep_sel $dep_sgs; do
- # filter out library deps, these do not belong in extralibs
- is_in $dep $LIBRARY_LIST && continue
- enabled $dep && eval append ${cfg}_extralibs ${dep}_extralibs
- done
+ eval [ x\$${cfg}_checking = xdone ] && continue
+ eval [ x\$${cfg}_checking = xinprogress ] && die "Circular dependency for $cfg."
+
+ eval "
+ dep_all=\$${cfg}_deps
+ dep_any=\$${cfg}_deps_any
+ dep_con=\$${cfg}_conflict
+ dep_sel=\$${cfg}_select
+ dep_sgs=\$${cfg}_suggest
+ dep_ifa=\$${cfg}_if
+ dep_ifn=\$${cfg}_if_any
+ "
+
+ # most of the time here $cfg has no deps - avoid costly no-op work
+ if [ "$dep_all$dep_any$dep_con$dep_sel$dep_sgs$dep_ifa$dep_ifn" ]; then
+ eval ${cfg}_checking=inprogress
+
+ set -- $cfg "$dep_all" "$dep_any" "$dep_con" "$dep_sel" "$dep_sgs" "$dep_ifa" "$dep_ifn"
+ check_deps $dep_all $dep_any $dep_con $dep_sel $dep_sgs $dep_ifa $dep_ifn
+ cfg=$1; dep_all=$2; dep_any=$3; dep_con=$4; dep_sel=$5 dep_sgs=$6; dep_ifa=$7; dep_ifn=$8
+
+ [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
+ [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
+ enabled_all $dep_all || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but not all dependencies are satisfied: $dep_all"; }
+ enabled_any $dep_any || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but not any dependency is satisfied: $dep_any"; }
+ disabled_all $dep_con || { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but some conflicting dependencies are unsatisfied: $dep_con"; }
+ disabled_any $dep_sel && { disable $cfg && requested $cfg && die "ERROR: $cfg requested, but some selected dependency is unsatisfied: $dep_sel"; }
+
+ enabled $cfg && enable_deep_weak $dep_sel $dep_sgs
+
+ for dep in $dep_all $dep_any $dep_sel $dep_sgs; do
+ # filter out library deps, these do not belong in extralibs
+ is_in $dep $LIBRARY_LIST && continue
+ enabled $dep && eval append ${cfg}_extralibs ${dep}_extralibs
+ done
+ fi
- disable ${cfg}_checking
+ eval ${cfg}_checking=done
done
}
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