Messages in this thread | | | Subject | Re: [PATCH v2 5/7] sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y | From | Christophe Leroy <> | Date | Thu, 30 Sep 2021 15:08:56 +0200 |
| |
Le 30/09/2021 à 14:58, Ard Biesheuvel a écrit : > THREAD_INFO_IN_TASK moved the CPU field out of thread_info, but this > causes some issues on architectures that define raw_smp_processor_id() > in terms of this field, due to the fact that #include'ing linux/sched.h > to get at struct task_struct is problematic in terms of circular > dependencies. > > Given that thread_info and task_struct are the same data structure > anyway when THREAD_INFO_IN_TASK=y, let's move it back so that having > access to the type definition of struct thread_info is sufficient to > reference the CPU number of the current task. > > Note that this requires THREAD_INFO_IN_TASK's definition of the > task_thread_info() helper to be updated, as task_cpu() takes a > pointer-to-const, whereas task_thread_info() (which is used to generate > lvalues as well), needs a non-const pointer. So make it a macro instead. > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Mark Rutland <mark.rutland@arm.com> > Acked-by: Michael Ellerman <mpe@ellerman.id.au> > --- > arch/arm64/kernel/asm-offsets.c | 1 - > arch/arm64/kernel/head.S | 2 +- > arch/powerpc/kernel/asm-offsets.c | 2 +- > arch/powerpc/kernel/smp.c | 2 +- > include/linux/sched.h | 13 +------------ > kernel/sched/sched.h | 4 ---- > 6 files changed, 4 insertions(+), 20 deletions(-) > > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index cee9f3e9f906..0bfc048221af 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -27,7 +27,6 @@ > int main(void) > { > DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm)); > - DEFINE(TSK_CPU, offsetof(struct task_struct, cpu)); > BLANK(); > DEFINE(TSK_TI_CPU, offsetof(struct task_struct, thread_info.cpu)); > DEFINE(TSK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags)); > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > index 17962452e31d..6a98f1a38c29 100644 > --- a/arch/arm64/kernel/head.S > +++ b/arch/arm64/kernel/head.S > @@ -412,7 +412,7 @@ SYM_FUNC_END(__create_page_tables) > scs_load \tsk > > adr_l \tmp1, __per_cpu_offset > - ldr w\tmp2, [\tsk, #TSK_CPU] > + ldr w\tmp2, [\tsk, #TSK_TI_CPU]
Why do you need to change the name ?
For powerpc64, you leave TASK_CPU.
> ldr \tmp1, [\tmp1, \tmp2, lsl #3] > set_this_cpu_offset \tmp1 > .endm > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c > index e563d3222d69..e37e4546034e 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -93,7 +93,7 @@ int main(void) > #endif /* CONFIG_PPC64 */ > OFFSET(TASK_STACK, task_struct, stack); > #ifdef CONFIG_SMP > - OFFSET(TASK_CPU, task_struct, cpu); > + OFFSET(TASK_CPU, task_struct, thread_info.cpu); > #endif > > #ifdef CONFIG_LIVEPATCH
...
| |