[-next,V10,10/10] riscv: stack: Add config of thread stack size
Commit Message
From: Guo Ren <guoren@linux.alibaba.com>
0cac21b02ba5 ("risc v: use 16KB kernel stack on 64-bit") increase the
thread size mandatory, but some scenarios, such as D1 with a small
memory footprint, would suffer from that. After independent irq stack
support, let's give users a choice to determine their custom stack size.
Link: https://lore.kernel.org/linux-riscv/5f6e6c39-b846-4392-b468-02202404de28@www.fastmail.com/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
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 | 10 ++++++++++
arch/riscv/include/asm/thread_info.h | 12 +-----------
2 files changed, 11 insertions(+), 11 deletions(-)
Comments
guoren@kernel.org writes:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> 0cac21b02ba5 ("risc v: use 16KB kernel stack on 64-bit") increase the
checkpatch complains here: Use "commit SHA...".
> thread size mandatory, but some scenarios, such as D1 with a small
> memory footprint, would suffer from that. After independent irq stack
> support, let's give users a choice to determine their custom stack size.
...and again, my "why is this in the generic entry" series rant. :-)
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>
> >
> > 0cac21b02ba5 ("risc v: use 16KB kernel stack on 64-bit") increase the
>
> checkpatch complains here: Use "commit SHA...".
Okay, I would check that.
>
> > thread size mandatory, but some scenarios, such as D1 with a small
> > memory footprint, would suffer from that. After independent irq stack
> > support, let's give users a choice to determine their custom stack size.
>
> ...and again, my "why is this in the generic entry" series rant. :-)
I would remove it from the generic entry series.
>
>
> Björn
@@ -455,6 +455,16 @@ config IRQ_STACKS
Add independent irq & softirq stacks for percpu to prevent kernel stack
overflows. We may save some memory footprint by disabling IRQ_STACKS.
+config THREAD_SIZE_ORDER
+ int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
+ range 0 4
+ default 1 if 32BIT && !KASAN
+ default 3 if 64BIT && KASAN
+ default 2
+ help
+ Specify the Pages of thread stack size (from 4KB to 64KB), which also
+ affects irq stack size, which is equal to thread stack size.
+
endmenu # "Platform type"
menu "Kernel features"
@@ -11,18 +11,8 @@
#include <asm/page.h>
#include <linux/const.h>
-#ifdef CONFIG_KASAN
-#define KASAN_STACK_ORDER 1
-#else
-#define KASAN_STACK_ORDER 0
-#endif
-
/* thread information allocation */
-#ifdef CONFIG_64BIT
-#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
-#else
-#define THREAD_SIZE_ORDER (1 + KASAN_STACK_ORDER)
-#endif
+#define THREAD_SIZE_ORDER CONFIG_THREAD_SIZE_ORDER
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
/*