Merge branch 'ps/upload-pack-buffer-more-writes'

Reduce system overhead "git upload-pack" spends on relaying "git
pack-objects" output to the "git fetch" running on the other end of
the connection.

* ps/upload-pack-buffer-more-writes:
  builtin/pack-objects: reduce lock contention when writing packfile data
  csum-file: drop `hashfd_throughput()`
  csum-file: introduce `hashfd_ext()`
  sideband: use writev(3p) to send pktlines
  wrapper: introduce writev(3p) wrappers
  compat/posix: introduce writev(3p) wrapper
  upload-pack: reduce lock contention when writing packfile data
  upload-pack: prefer flushing data over sending keepalive
  upload-pack: adapt keepalives based on buffering
  upload-pack: fix debug statement when flushing packfile data

1 files changed, 4 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index c619b5405b..bf2228de9d 100644
--- a/Makefile
+++ b/Makefile
@@ -2027,6 +2027,10 @@ ifdef NO_PREAD
 	COMPAT_CFLAGS += -DNO_PREAD
 	COMPAT_OBJS += compat/pread.o
 endif
+ifdef NO_WRITEV
+	COMPAT_CFLAGS += -DNO_WRITEV
+	COMPAT_OBJS += compat/writev.o
+endif
 ifdef NO_FAST_WORKING_DIRECTORY
 	BASIC_CFLAGS += -DNO_FAST_WORKING_DIRECTORY
 endif