| Message ID | 20241009105709.887510-4-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Lazy preemption leftovers | expand |
On Wed, Oct 09, 2024 at 12:50:57PM +0200, Sebastian Andrzej Siewior wrote: > From: Jisheng Zhang <jszhang@kernel.org> > > riscv has switched to GENERIC_ENTRY, so adding PREEMPT_LAZY is as simple > as adding TIF_NEED_RESCHED_LAZY related definitions and enabling > ARCH_HAS_PREEMPT_LAZY. > > [bigeasy: Replace old PREEMPT_AUTO bits with new PREEMPT_LAZY ] > > Cc: Paul Walmsley <paul.walmsley@sifive.com> > Cc: Palmer Dabbelt <palmer@dabbelt.com> > Cc: Albert Ou <aou@eecs.berkeley.edu> > Cc: linux-riscv@lists.infradead.org > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/thread_info.h | 2 ++ > 2 files changed, 3 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 62545946ecf43..3516c58480612 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -39,6 +39,7 @@ config RISCV > select ARCH_HAS_MMIOWB > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > select ARCH_HAS_PMEM_API > + select ARCH_HAS_PREEMPT_LAZY > select ARCH_HAS_PREPARE_SYNC_CORE_CMD > select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU > select ARCH_HAS_PTE_SPECIAL > diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h > index 9c10fb180f438..8b5a5ddea4293 100644 > --- a/arch/riscv/include/asm/thread_info.h > +++ b/arch/riscv/include/asm/thread_info.h > @@ -107,6 +107,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); > * - pending work-to-be-done flags are in lowest half-word > * - other flags in upper half-word(s) > */ > +#define TIF_NEED_RESCHED_LAZY 0 /* Lazy rescheduling needed */ > #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ > #define TIF_SIGPENDING 2 /* signal pending */ > #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ So for x86 I shuffled the flags around to have the two NEED_RESCHED ones side-by-side. Not strictly required ofcourse, but...
On 2024-10-09 15:03:07 [+0200], Peter Zijlstra wrote: > > diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h > > index 9c10fb180f438..8b5a5ddea4293 100644 > > --- a/arch/riscv/include/asm/thread_info.h > > +++ b/arch/riscv/include/asm/thread_info.h > > @@ -107,6 +107,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); > > * - pending work-to-be-done flags are in lowest half-word > > * - other flags in upper half-word(s) > > */ > > +#define TIF_NEED_RESCHED_LAZY 0 /* Lazy rescheduling needed */ > > #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ > > #define TIF_SIGPENDING 2 /* signal pending */ > > #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ > > So for x86 I shuffled the flags around to have the two NEED_RESCHED ones > side-by-side. Not strictly required ofcourse, but... I can shuffle them. I don't think the riscv camp will complain (saying this for them to actual complain if so). Sebastian
On Wed, 09 Oct 2024 06:05:30 PDT (-0700), bigeasy@linutronix.de wrote: > On 2024-10-09 15:03:07 [+0200], Peter Zijlstra wrote: >> > diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h >> > index 9c10fb180f438..8b5a5ddea4293 100644 >> > --- a/arch/riscv/include/asm/thread_info.h >> > +++ b/arch/riscv/include/asm/thread_info.h >> > @@ -107,6 +107,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); >> > * - pending work-to-be-done flags are in lowest half-word >> > * - other flags in upper half-word(s) >> > */ >> > +#define TIF_NEED_RESCHED_LAZY 0 /* Lazy rescheduling needed */ >> > #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ >> > #define TIF_SIGPENDING 2 /* signal pending */ >> > #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ >> >> So for x86 I shuffled the flags around to have the two NEED_RESCHED ones >> side-by-side. Not strictly required ofcourse, but... > > I can shuffle them. I don't think the riscv camp will complain (saying > this for them to actual complain if so). Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 62545946ecf43..3516c58480612 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -39,6 +39,7 @@ config RISCV select ARCH_HAS_MMIOWB select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API + select ARCH_HAS_PREEMPT_LAZY select ARCH_HAS_PREPARE_SYNC_CORE_CMD select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU select ARCH_HAS_PTE_SPECIAL diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index 9c10fb180f438..8b5a5ddea4293 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -107,6 +107,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); * - pending work-to-be-done flags are in lowest half-word * - other flags in upper half-word(s) */ +#define TIF_NEED_RESCHED_LAZY 0 /* Lazy rescheduling needed */ #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ @@ -117,6 +118,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); #define TIF_32BIT 11 /* compat-mode 32bit process */ #define TIF_RISCV_V_DEFER_RESTORE 12 /* restore Vector before returing to user */ +#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)