On 2016-06-07 11:38, Michal Marek wrote: > On 2016-06-07 03:38, Zanoni, Paulo R wrote: >> Hi >> >> I recently noticed that alternating between "make" and "make targz-pkg" >> rebuilds the whole Kernel. This was not happening before. As a Kernel >> developer, my build/install/test environment heavily relies on the fact >> that "make targz-pkg" only quickly generates the tarball if everything >> is already built, so this change is heavily impacting my development >> environment. >> >> I did some bisection and concluded that the first bad commit is: >> >> commit 9c8fa9bc08f60ac657751daba9fccf828a36cfed >> Author: Masahiro Yamada >> Date: Sat May 7 15:48:26 2016 +0900 >> kbuild: fix if_change and friends to consider argument order >> >> I also verified that if I just revert this commit on top of the >> most recent tree it goes back to the usual behavior. >> >> I read the commit message and it seems that some unneeded rebuilds are >> somewhat expected, but I can't understand why such a change in the >> command line like the one I did triggers everything to be rebuilt. >> IMHO, it really shouldn't. I also wonder that maybe the regression I'm >> experiencing was not expected in the original change, so maybe there's >> a way to keep the original improvement caused by the mentioned patch >> without the regression I'm experiencing. >> >> How to reproduce (exact commands I used at every bisect step): >> >> $ make tinyconfig >> $ time make -j4 V=2 # this should build things >> $ time make -j4 V=2 # just to make sure nothing will be rebuilt >> $ time make -j4 V=2 targz-pkg > > I can reproduce it. Try the attached patch. Michal
>From 86536cfcd776b5d9e238a4690756028799122a86 Mon Sep 17 00:00:00 2001 From: Michal Marek <mmarek@xxxxxxxx> Date: Tue, 7 Jun 2016 11:57:02 +0200 Subject: [PATCH] kbuild: Initialize NOSTDINC_CFLAGS The variable is exported, so it needs to be cleared to avoid duplicating its content when running make from within make (e.g. in the packaging targets). Signed-off-by: Michal Marek <mmarek@xxxxxxxx> --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index 0f9cb36d45c2..1a85efa216ac 100644 --- a/Makefile +++ b/Makefile @@ -359,6 +359,7 @@ CHECK = sparse CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ -Wbitwise -Wno-return-void $(CF) +NOSTDINC_FLAGS = CFLAGS_MODULE = AFLAGS_MODULE = LDFLAGS_MODULE = -- 2.6.2
