From: Guo Ren <guoren@linux.alibaba.com>
Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The
irq and softirq use the same independent irq_stack of percpu by time
division multiplexing.
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/Kconfig | 7 ++++---
arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0a9d4bdc0338..bd4c4ae4cdc9 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -447,12 +447,13 @@ config FPU
If you don't know what to do here, say Y.
config IRQ_STACKS
- bool "Independent irq stacks" if EXPERT
+ bool "Independent irq & softirq stacks" if EXPERT
default y
select HAVE_IRQ_EXIT_ON_IRQ_STACK
+ select HAVE_SOFTIRQ_ON_OWN_STACK
help
- Add independent irq stacks for percpu to prevent kernel stack overflows.
- We may save some memory footprint by disabling IRQ_STACKS.
+ Add independent irq & softirq stacks for percpu to prevent kernel stack
+ overflows. We may save some memory footprint by disabling IRQ_STACKS.
endmenu # "Platform type"
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 5d77f692b198..a6406da34937 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -11,6 +11,7 @@
#include <linux/seq_file.h>
#include <asm/smp.h>
#include <asm/vmap_stack.h>
+#include <asm/softirq_stack.h>
#ifdef CONFIG_IRQ_STACKS
static DEFINE_PER_CPU(ulong *, irq_stack_ptr);
@@ -38,6 +39,38 @@ static void init_irq_stacks(void)
per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
}
#endif /* CONFIG_VMAP_STACK */
+
+#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
+void do_softirq_own_stack(void)
+{
+#ifdef CONFIG_IRQ_STACKS
+ if (on_thread_stack()) {
+ ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
+ + IRQ_STACK_SIZE/sizeof(ulong);
+ __asm__ __volatile(
+ "addi sp, sp, -"RISCV_SZPTR "\n"
+ REG_S" ra, (sp) \n"
+ "addi sp, sp, -"RISCV_SZPTR "\n"
+ REG_S" s0, (sp) \n"
+ "addi s0, sp, 2*"RISCV_SZPTR "\n"
+ "move sp, %[sp] \n"
+ "call __do_softirq \n"
+ "addi sp, s0, -2*"RISCV_SZPTR"\n"
+ REG_L" s0, (sp) \n"
+ "addi sp, sp, "RISCV_SZPTR "\n"
+ REG_L" ra, (sp) \n"
+ "addi sp, sp, "RISCV_SZPTR "\n"
+ :
+ : [sp] "r" (sp)
+ : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+ "t0", "t1", "t2", "t3", "t4", "t5", "t6",
+ "memory");
+ } else
+#endif
+ __do_softirq();
+}
+#endif /* CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK */
+
#else
static void init_irq_stacks(void) {}
#endif /* CONFIG_IRQ_STACKS */
--
2.36.1guoren@kernel.org writes:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The
> irq and softirq use the same independent irq_stack of percpu by time
> division multiplexing.
>
> Tested-by: Jisheng Zhang <jszhang@kernel.org>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> ---
> arch/riscv/Kconfig | 7 ++++---
> arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++
> 2 files changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0a9d4bdc0338..bd4c4ae4cdc9 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -447,12 +447,13 @@ config FPU
> If you don't know what to do here, say Y.
>
> config IRQ_STACKS
> - bool "Independent irq stacks" if EXPERT
> + bool "Independent irq & softirq stacks" if EXPERT
> default y
> select HAVE_IRQ_EXIT_ON_IRQ_STACK
> + select HAVE_SOFTIRQ_ON_OWN_STACK
HAVE_IRQ_EXIT_ON_IRQ_STACK is used by softirq.c Shouldn't that be
selected introduced in this patch, instead of the previous one?
> help
> - Add independent irq stacks for percpu to prevent kernel stack overflows.
> - We may save some memory footprint by disabling IRQ_STACKS.
> + Add independent irq & softirq stacks for percpu to prevent kernel stack
> + overflows. We may save some memory footprint by disabling IRQ_STACKS.
Same comment from previous patch. Please use the same wording/config as
other archs.
> endmenu # "Platform type"
>
> diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
> index 5d77f692b198..a6406da34937 100644
> --- a/arch/riscv/kernel/irq.c
> +++ b/arch/riscv/kernel/irq.c
> @@ -11,6 +11,7 @@
> #include <linux/seq_file.h>
> #include <asm/smp.h>
> #include <asm/vmap_stack.h>
> +#include <asm/softirq_stack.h>
>
> #ifdef CONFIG_IRQ_STACKS
> static DEFINE_PER_CPU(ulong *, irq_stack_ptr);
> @@ -38,6 +39,38 @@ static void init_irq_stacks(void)
> per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
> }
> #endif /* CONFIG_VMAP_STACK */
> +
> +#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
> +void do_softirq_own_stack(void)
> +{
> +#ifdef CONFIG_IRQ_STACKS
> + if (on_thread_stack()) {
> + ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
> + + IRQ_STACK_SIZE/sizeof(ulong);
> + __asm__ __volatile(
> + "addi sp, sp, -"RISCV_SZPTR "\n"
> + REG_S" ra, (sp) \n"
> + "addi sp, sp, -"RISCV_SZPTR "\n"
> + REG_S" s0, (sp) \n"
> + "addi s0, sp, 2*"RISCV_SZPTR "\n"
> + "move sp, %[sp] \n"
> + "call __do_softirq \n"
> + "addi sp, s0, -2*"RISCV_SZPTR"\n"
> + REG_L" s0, (sp) \n"
> + "addi sp, sp, "RISCV_SZPTR "\n"
> + REG_L" ra, (sp) \n"
> + "addi sp, sp, "RISCV_SZPTR "\n"
> + :
> + : [sp] "r" (sp)
> + : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
> + "t0", "t1", "t2", "t3", "t4", "t5", "t6",
> + "memory");
Same as previous patch. Please avoid C&P and have a look at how
call_on_stack is done on x86.
Björn
On Thu, Dec 8, 2022 at 6:12 PM Björn Töpel <bjorn@kernel.org> wrote:
>
> guoren@kernel.org writes:
>
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The
> > irq and softirq use the same independent irq_stack of percpu by time
> > division multiplexing.
> >
> > Tested-by: Jisheng Zhang <jszhang@kernel.org>
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> > arch/riscv/Kconfig | 7 ++++---
> > arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++
> > 2 files changed, 37 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index 0a9d4bdc0338..bd4c4ae4cdc9 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -447,12 +447,13 @@ config FPU
> > If you don't know what to do here, say Y.
> >
> > config IRQ_STACKS
> > - bool "Independent irq stacks" if EXPERT
> > + bool "Independent irq & softirq stacks" if EXPERT
> > default y
> > select HAVE_IRQ_EXIT_ON_IRQ_STACK
> > + select HAVE_SOFTIRQ_ON_OWN_STACK
>
> HAVE_IRQ_EXIT_ON_IRQ_STACK is used by softirq.c Shouldn't that be
> selected introduced in this patch, instead of the previous one?
This patch depends on the previous one. And the previous one could
work separately.
>
> > help
> > - Add independent irq stacks for percpu to prevent kernel stack overflows.
> > - We may save some memory footprint by disabling IRQ_STACKS.
> > + Add independent irq & softirq stacks for percpu to prevent kernel stack
> > + overflows. We may save some memory footprint by disabling IRQ_STACKS.
>
> Same comment from previous patch. Please use the same wording/config as
> other archs.
>
> > endmenu # "Platform type"
> >
> > diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
> > index 5d77f692b198..a6406da34937 100644
> > --- a/arch/riscv/kernel/irq.c
> > +++ b/arch/riscv/kernel/irq.c
> > @@ -11,6 +11,7 @@
> > #include <linux/seq_file.h>
> > #include <asm/smp.h>
> > #include <asm/vmap_stack.h>
> > +#include <asm/softirq_stack.h>
> >
> > #ifdef CONFIG_IRQ_STACKS
> > static DEFINE_PER_CPU(ulong *, irq_stack_ptr);
> > @@ -38,6 +39,38 @@ static void init_irq_stacks(void)
> > per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
> > }
> > #endif /* CONFIG_VMAP_STACK */
> > +
> > +#ifdef CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK
> > +void do_softirq_own_stack(void)
> > +{
> > +#ifdef CONFIG_IRQ_STACKS
> > + if (on_thread_stack()) {
> > + ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
> > + + IRQ_STACK_SIZE/sizeof(ulong);
> > + __asm__ __volatile(
> > + "addi sp, sp, -"RISCV_SZPTR "\n"
> > + REG_S" ra, (sp) \n"
> > + "addi sp, sp, -"RISCV_SZPTR "\n"
> > + REG_S" s0, (sp) \n"
> > + "addi s0, sp, 2*"RISCV_SZPTR "\n"
> > + "move sp, %[sp] \n"
> > + "call __do_softirq \n"
> > + "addi sp, s0, -2*"RISCV_SZPTR"\n"
> > + REG_L" s0, (sp) \n"
> > + "addi sp, sp, "RISCV_SZPTR "\n"
> > + REG_L" ra, (sp) \n"
> > + "addi sp, sp, "RISCV_SZPTR "\n"
> > + :
> > + : [sp] "r" (sp)
> > + : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
> > + "t0", "t1", "t2", "t3", "t4", "t5", "t6",
> > + "memory");
>
> Same as previous patch. Please avoid C&P and have a look at how
> call_on_stack is done on x86.
Okay.
>
>
> Björn
--
Best Regards
Guo Ren
Guo Ren <guoren@kernel.org> writes: > On Thu, Dec 8, 2022 at 6:12 PM Björn Töpel <bjorn@kernel.org> wrote: >> >> guoren@kernel.org writes: >> >> > From: Guo Ren <guoren@linux.alibaba.com> >> > >> > Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The >> > irq and softirq use the same independent irq_stack of percpu by time >> > division multiplexing. >> > >> > Tested-by: Jisheng Zhang <jszhang@kernel.org> >> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com> >> > Signed-off-by: Guo Ren <guoren@kernel.org> >> > --- >> > arch/riscv/Kconfig | 7 ++++--- >> > arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++ >> > 2 files changed, 37 insertions(+), 3 deletions(-) >> > >> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> > index 0a9d4bdc0338..bd4c4ae4cdc9 100644 >> > --- a/arch/riscv/Kconfig >> > +++ b/arch/riscv/Kconfig >> > @@ -447,12 +447,13 @@ config FPU >> > If you don't know what to do here, say Y. >> > >> > config IRQ_STACKS >> > - bool "Independent irq stacks" if EXPERT >> > + bool "Independent irq & softirq stacks" if EXPERT >> > default y >> > select HAVE_IRQ_EXIT_ON_IRQ_STACK >> > + select HAVE_SOFTIRQ_ON_OWN_STACK >> >> HAVE_IRQ_EXIT_ON_IRQ_STACK is used by softirq.c Shouldn't that be >> selected introduced in this patch, instead of the previous one? > This patch depends on the previous one. And the previous one could > work separately. Let me try to be more clear: IRQ_STACKS should be introduced in the previous patch, which adds per-cpu stacks to hardirq. This patch adds per-cpu stacks for softirq, and the softirq related selects: select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_SOFTIRQ_ON_OWN_STACK Hence, the "HAVE_IRQ_EXIT_ON_IRQ_STACK" select should be part of *this* patch, not the previous. Or am I missing something? Björn
On Fri, Dec 9, 2022 at 3:50 PM Björn Töpel <bjorn@kernel.org> wrote:
>
> Guo Ren <guoren@kernel.org> writes:
>
> > On Thu, Dec 8, 2022 at 6:12 PM Björn Töpel <bjorn@kernel.org> wrote:
> >>
> >> guoren@kernel.org writes:
> >>
> >> > From: Guo Ren <guoren@linux.alibaba.com>
> >> >
> >> > Add the HAVE_SOFTIRQ_ON_OWN_STACK feature for the IRQ_STACKS config. The
> >> > irq and softirq use the same independent irq_stack of percpu by time
> >> > division multiplexing.
> >> >
> >> > Tested-by: Jisheng Zhang <jszhang@kernel.org>
> >> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> >> > Signed-off-by: Guo Ren <guoren@kernel.org>
> >> > ---
> >> > arch/riscv/Kconfig | 7 ++++---
> >> > arch/riscv/kernel/irq.c | 33 +++++++++++++++++++++++++++++++++
> >> > 2 files changed, 37 insertions(+), 3 deletions(-)
> >> >
> >> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> >> > index 0a9d4bdc0338..bd4c4ae4cdc9 100644
> >> > --- a/arch/riscv/Kconfig
> >> > +++ b/arch/riscv/Kconfig
> >> > @@ -447,12 +447,13 @@ config FPU
> >> > If you don't know what to do here, say Y.
> >> >
> >> > config IRQ_STACKS
> >> > - bool "Independent irq stacks" if EXPERT
> >> > + bool "Independent irq & softirq stacks" if EXPERT
> >> > default y
> >> > select HAVE_IRQ_EXIT_ON_IRQ_STACK
> >> > + select HAVE_SOFTIRQ_ON_OWN_STACK
> >>
> >> HAVE_IRQ_EXIT_ON_IRQ_STACK is used by softirq.c Shouldn't that be
> >> selected introduced in this patch, instead of the previous one?
> > This patch depends on the previous one. And the previous one could
> > work separately.
>
> Let me try to be more clear: IRQ_STACKS should be introduced in the
> previous patch, which adds per-cpu stacks to hardirq. This patch adds
> per-cpu stacks for softirq, and the softirq related selects:
>
> select HAVE_IRQ_EXIT_ON_IRQ_STACK
> select HAVE_SOFTIRQ_ON_OWN_STACK
>
> Hence, the "HAVE_IRQ_EXIT_ON_IRQ_STACK" select should be part of *this*
> patch, not the previous.
>
> Or am I missing something?
You are right, HAVE_IRQ_EXIT_ON_IRQ_STACK is belong to SOFTIRQ:
static inline void invoke_softirq(void)
{
...
if (!force_irqthreads() || !__this_cpu_read(ksoftirqd)) {
#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
...
__do_softirq();
#else
...
do_softirq_own_stack();
#endif
...
}
I would fix that in the next version.
>
>
> Björn
--
Best Regards
Guo Ren
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