On 5/16/16, Sedat Dilek <sedat.di...@gmail.com> wrote: > On 5/16/16, Peter Zijlstra <pet...@infradead.org> wrote: >> On Mon, May 16, 2016 at 07:42:35PM +0200, Sedat Dilek wrote: >> >>> Unfortunately, I could not reproduce this again with none of my >>> 183-kernels. >>> When I first hit a "chain_key collision" issue, it was hard to >>> redproduce, >>> so. >>> Any idea, how I can "force" this? >> >> Nope; I wish I knew, that'd be so much easier to work with :/ >> >> I'm hoping someone will report a reproducer, even something that >> triggers once every 5-10 runs would be awesome. >> >> In any case, like I've explained before, nothing regressed as such, we >> only added this new warning under DEBUG_LOCKDEP because we want to >> better understand the condition that triggers it. >> >> If it bothers you, just turn off DEBUG_LOCKDEP and know that your kernel >> is as reliable as it was before. OTOH, if you do keep it on, please >> let me know if you can (semi) reliably trigger this, as I'd really like >> to have a better understanding. >> > > OK, I keep checking my logs. > > I refreshed your patch Ingo pointed me to. > > But it fails like this (on top of Linux v4.6 final)... > [...] > if [ "" = "-pg" ]; then if [ kernel/locking/mutex-debug.o != > "scripts/mod/empty.o" ]; then ./scripts/recordmcount > "kernel/locking/mutex-debug.o"; fi; fi; > mycompiler -Wp,-MD,kernel/locking/.lockdep.o.d -nostdinc -isystem > /usr/lib/gcc/x86_64-linux-gnu/4.9/include -nostdinc -isystem > /usr/lib/gcc/x86_64-linux-gnu/4.9/include -I./arch/x86/include > -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated > -Iinclude -I./arch/x86/include/uapi -Iarch/x86/include/generated/uapi > -I./include/uapi -Iinclude/generated/uapi -include > ./include/linux/kconfig.h -D__KERNEL__ -Wall -Wundef > -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common > -Werror-implicit-function-declaration -Wno-format-security -std=gnu89 > -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -m64 -falign-jumps=1 > -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 > -mpreferred-stack-boundary=3 -mtune=generic -mno-red-zone > -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args > -DCONFIG_X86_X32_ABI -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 > -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1 -DCONFIG_AS_SSSE3=1 > -DCONFIG_AS_CRC32=1 -DCONFIG_AS_AVX=1 -DCONFIG_AS_AVX2=1 -pipe > -Wno-sign-compare -fno-asynchronous-unwind-tables > -fno-delete-null-pointer-checks -O2 --param=allow-store-data-races=0 > -Wframe-larger-than=1024 -fno-stack-protector > -Wno-unused-but-set-variable -fno-omit-frame-pointer > -fno-optimize-sibling-calls -fno-var-tracking-assignments -mfentry > -DCC_USING_FENTRY -Wdeclaration-after-statement -Wno-pointer-sign > -fno-strict-overflow -fconserve-stack -Werror=implicit-int > -Werror=strict-prototypes -Werror=date-time -DCC_HAVE_ASM_GOTO > -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(lockdep)" > -D"KBUILD_MODNAME=KBUILD_STR(lockdep)" -c -o > kernel/locking/.tmp_lockdep.o kernel/locking/lockdep.c > kernel/locking/lockdep.c: In function 'print_chain_keys_held_locks': > kernel/locking/lockdep.c:2034:2: error: too few arguments to function > 'print_chain_key_iteration' > print_chain_key_iteration(hlock_next->class_idx, chain_key); > ^ > kernel/locking/lockdep.c:2006:12: note: declared here > static u64 print_chain_key_iteration(int class_idx, u64 chain_key, > u64 prev_key) > ^ > make[4]: *** [kernel/locking/lockdep.o] Error 1 > make[3]: *** [kernel/locking] Error 2 > make[2]: *** [kernel] Error 2 > [...] >
Is the attached fix correct? - Sedat - P.S.: Attached is a refreshed version of your original proposal patch which does not compile correctly.
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 5dc21eb101b0..b771a691b5e8 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2031,7 +2031,8 @@ print_chain_keys_held_locks(struct task_struct *curr,
struct held_lock *hlock_ne
print_lock(hlock);
}
- print_chain_key_iteration(hlock_next->class_idx, chain_key);
+ print_chain_key_iteration(hlock_next->class_idx, chain_key,
+ hlock->prev_chain_key);
print_lock(hlock_next);
}
0001-locking-lockdep-Some-more-additional-chain_key-colli.patch
Description: Binary data
