merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 24 insertions, 23 deletions

diff --git a/third_party/git/t/perf/p5302-pack-index.sh b/third_party/git/t/perf/p5302-pack-index.sh
index a9b3e112d982..228593d9ad6b 100755
--- a/third_party/git/t/perf/p5302-pack-index.sh
+++ b/third_party/git/t/perf/p5302-pack-index.sh
@@ -13,35 +13,36 @@ test_expect_success 'repack' '
 	export PACK
 '
 
-test_perf 'index-pack 0 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=1 --stdin < $PACK
-'
-
-test_perf 'index-pack 1 thread ' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git GIT_FORCE_THREADS=1 git index-pack --threads=1 --stdin < $PACK
+# Rather than counting up and doubling each time, count down from the endpoint,
+# halving each time. That ensures that our final test uses as many threads as
+# CPUs, even if it isn't a power of 2.
+test_expect_success 'set up thread-counting tests' '
+	t=$(test-tool online-cpus) &&
+	threads= &&
+	while test $t -gt 0
+	do
+		threads="$t $threads"
+		t=$((t / 2))
+	done
 '
 
-test_perf 'index-pack 2 threads' '
+test_perf PERF_EXTRA 'index-pack 0 threads' '
 	rm -rf repo.git &&
 	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=2 --stdin < $PACK
-'
-
-test_perf 'index-pack 4 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=4 --stdin < $PACK
+	GIT_DIR=repo.git git index-pack --threads=1 --stdin < $PACK
 '
 
-test_perf 'index-pack 8 threads' '
-	rm -rf repo.git &&
-	git init --bare repo.git &&
-	GIT_DIR=repo.git git index-pack --threads=8 --stdin < $PACK
-'
+for t in $threads
+do
+	THREADS=$t
+	export THREADS
+	test_perf PERF_EXTRA "index-pack $t threads" '
+		rm -rf repo.git &&
+		git init --bare repo.git &&
+		GIT_DIR=repo.git GIT_FORCE_THREADS=1 \
+		git index-pack --threads=$THREADS --stdin <$PACK
+	'
+done
 
 test_perf 'index-pack default number of threads' '
 	rm -rf repo.git &&