| Message ID | 1467838845-17059-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/Makefile b/Makefile index 6b72df3..d633ed1 100644 --- a/Makefile +++ b/Makefile @@ -376,7 +376,7 @@ AFLAGS_MODULE = LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage +CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im # Use USERINCLUDE when you must reference the UAPI directories only.
This is a note to let you know that I have just added a patch titled gcov: disable tree-loop-im to reduce stack usage to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt23. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 379f9ede8f0867333249f92f55cebfd995d60223 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@arndb.de> Date: Mon, 25 Apr 2016 17:35:30 +0200 Subject: gcov: disable tree-loop-im to reduce stack usage commit c87bf431448b404a6ef5fbabd74c0e3e42157a7f upstream. Enabling CONFIG_GCOV_PROFILE_ALL produces us a lot of warnings like lib/lz4/lz4hc_compress.c: In function 'lz4_compresshcctx': lib/lz4/lz4hc_compress.c:514:1: warning: the frame size of 1504 bytes is larger than 1024 bytes [-Wframe-larger-than=] After some investigation, I found that this behavior started with gcc-4.9, and opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69702. A suggested workaround for it is to use the -fno-tree-loop-im flag that turns off one of the optimization stages in gcc, so the code runs a little slower but does not use excessive amounts of stack. We could make this conditional on the gcc version, but I could not find an easy way to do this in Kbuild and the benefit would be fairly small, given that most of the gcc version in production are affected now. I'm marking this for 'stable' backports because it addresses a bug with code generation in gcc that exists in all kernel versions with the affected gcc releases. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.7.4