The patch titled percpu: fix DEBUG_PREEMPT per_cpu checking has been added to the -mm tree. Its filename is percpu-fix-debug_preempt-per_cpu-checking.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: percpu: fix DEBUG_PREEMPT per_cpu checking From: Hugh Dickins <hugh@xxxxxxxxxxx> Recent percpu changes have broken CONFIG_DEBUG_PREEMPT's per_cpu checking on several architectures. On s390, sparc64 and x86 it's been weakened to not checking at all; whereas on powerpc64 it's become too strict, issuing warnings from __raw_get_cpu_var in io_schedule and init_timer for example. Fix this by weakening powerpc's __my_cpu_offset to use the non-checking local_paca instead of get_paca (which itself contains such a check); and strengthening the generic my_cpu_offset to go the old slow way via smp_processor_id when CONFIG_DEBUG_PREEMPT (debug_smp_processor_id is where all the knowledge of what's correct when lives). Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx> Cc: Mike Travis <travis@xxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/asm-generic/percpu.h | 2 ++ include/asm-powerpc/percpu.h | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff -puN include/asm-generic/percpu.h~percpu-fix-debug_preempt-per_cpu-checking include/asm-generic/percpu.h --- a/include/asm-generic/percpu.h~percpu-fix-debug_preempt-per_cpu-checking +++ a/include/asm-generic/percpu.h @@ -32,6 +32,8 @@ extern unsigned long __per_cpu_offset[NR */ #ifndef __my_cpu_offset #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) +#endif +#ifdef CONFIG_DEBUG_PREEMPT #define my_cpu_offset per_cpu_offset(smp_processor_id()) #else #define my_cpu_offset __my_cpu_offset diff -puN include/asm-powerpc/percpu.h~percpu-fix-debug_preempt-per_cpu-checking include/asm-powerpc/percpu.h --- a/include/asm-powerpc/percpu.h~percpu-fix-debug_preempt-per_cpu-checking +++ a/include/asm-powerpc/percpu.h @@ -13,7 +13,7 @@ #include <asm/paca.h> #define __per_cpu_offset(cpu) (paca[cpu].data_offset) -#define __my_cpu_offset get_paca()->data_offset +#define __my_cpu_offset local_paca->data_offset #define per_cpu_offset(x) (__per_cpu_offset(x)) #endif /* CONFIG_SMP */ _ Patches currently in -mm which might be from hugh@xxxxxxxxxxx are origin.patch git-unionfs.patch git-x86.patch percpu-fix-debug_preempt-per_cpu-checking.patch r-o-bind-mounts-track-number-of-mount-writers.patch procfs-task-exe-symlink.patch procfs-task-exe-symlink-fix.patch prio_tree-debugging-patch.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html