Messages in this thread Patch in this message | | | Date | Mon, 7 Jun 2021 08:19:39 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [kbuild-all] Re: kernel/rcu/tree.c:2073:23: warning: stack frame size of 2704 bytes in function 'rcu_gp_kthread' |
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On Mon, Jun 07, 2021 at 05:18:21PM +0800, Rong Chen wrote: > > > On 6/6/21 12:49 PM, Paul E. McKenney wrote: > > On Sun, Jun 06, 2021 at 12:19:57PM +0800, kernel test robot wrote: > > > Hi Paul, > > > > > > FYI, the error/warning still remains. > > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > > head: f5b6eb1e018203913dfefcf6fa988649ad11ad6e > > > commit: 7dffe01765d9309b8bd5505503933ec0ec53d192 rcu: Add lockdep_assert_irqs_disabled() to raw_spin_unlock_rcu_node() macros > > > date: 5 months ago > > > config: powerpc-randconfig-r023-20210606 (attached as .config) > > > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 551a697c5cf33275b66add4fc467fcf59084cffb) > > > reproduce (this is a W=1 build): > > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > > > chmod +x ~/bin/make.cross > > > # install powerpc cross compiling tool for clang build > > > # apt-get install binutils-powerpc-linux-gnu > > > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7dffe01765d9309b8bd5505503933ec0ec53d192 > > > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > > > git fetch --no-tags linus master > > > git checkout 7dffe01765d9309b8bd5505503933ec0ec53d192 > > > # save the attached .config to linux build tree > > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc > > > > > > If you fix the issue, kindly add following tag as appropriate > > > Reported-by: kernel test robot <lkp@intel.com> > > > > > > All warnings (new ones prefixed by >>): > > > > > > In file included from kernel/rcu/tree.c:21: > > > In file included from include/linux/kernel.h:12: > > > In file included from include/linux/bitops.h:29: > > > In file included from arch/powerpc/include/asm/bitops.h:62: > > > arch/powerpc/include/asm/barrier.h:49:9: warning: '__lwsync' macro redefined [-Wmacro-redefined] > > > #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") > > > ^ > > > <built-in>:310:9: note: previous definition is here > > > #define __lwsync __builtin_ppc_lwsync > > > ^ > > > > > kernel/rcu/tree.c:2073:23: warning: stack frame size of 2704 bytes in function 'rcu_gp_kthread' [-Wframe-larger-than=] > > > static int __noreturn rcu_gp_kthread(void *unused) > > Does -rcu commit 2f20de99a63b ("rcu: Make rcu_gp_cleanup() be noinline > > for tracing") help? > > Hi Paul, > > The stack frame size decreased to 2256 bytes: > > kernel/rcu/tree.c:2129:23: warning: stack frame size of 2256 bytes in > function 'rcu_gp_kthread' [-Wframe-larger-than=]
Very good, thank you! Does the following patch (in addition to that commit) also help?
Thanx, Paul
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diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 13bd8eee62bf..ef435aeac993 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1737,7 +1737,7 @@ static void rcu_strict_gp_boundary(void *unused) /* * Initialize a new grace period. Return false if no grace period required. */ -static bool rcu_gp_init(void) +static noinline bool rcu_gp_init(void) { unsigned long firstseq; unsigned long flags; @@ -1931,7 +1931,7 @@ static void rcu_gp_fqs(bool first_time) /* * Loop doing repeated quiescent-state forcing until the grace period ends. */ -static void rcu_gp_fqs_loop(void) +static noinline void rcu_gp_fqs_loop(void) { bool first_gp_fqs; int gf = 0;
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