When cacheinfo_sysfs_init() is executed, the general weak function
init_cache_level() returns -ENOENT, causing failure to add the "cache"
node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
function on RISC-V to fix it.
Signed-off-by: Yunhui Cui <[email protected]>
---
arch/riscv/kernel/cacheinfo.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
index 09e9b88110d1..be9169a38bac 100644
--- a/arch/riscv/kernel/cacheinfo.c
+++ b/arch/riscv/kernel/cacheinfo.c
@@ -71,6 +71,12 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
this_leaf->type = type;
}
+int init_cache_level(unsigned int cpu)
+{
+ /* The topology has been parsed by acpi or dt, return true. */
+ return 0;
+}
+
int populate_cache_leaves(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
--
2.20.1
On Mon, Jan 22, 2024 at 09:35:10AM +0800, Yunhui Cui wrote:
> When cacheinfo_sysfs_init() is executed, the general weak function
> init_cache_level() returns -ENOENT, causing failure to add the "cache"
> node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
> function on RISC-V to fix it.
If you recall correctly, I asked you to explain how to reproduce this
when you sent the patch.
Thanks,
Conor.
>
> Signed-off-by: Yunhui Cui <[email protected]>
> ---
> arch/riscv/kernel/cacheinfo.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
> index 09e9b88110d1..be9169a38bac 100644
> --- a/arch/riscv/kernel/cacheinfo.c
> +++ b/arch/riscv/kernel/cacheinfo.c
> @@ -71,6 +71,12 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
> this_leaf->type = type;
> }
>
> +int init_cache_level(unsigned int cpu)
> +{
> + /* The topology has been parsed by acpi or dt, return true. */
> + return 0;
> +}
> +
> int populate_cache_leaves(unsigned int cpu)
> {
> struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
> --
> 2.20.1
>
>
Hi Conor,
On Mon, Jan 22, 2024 at 4:09 PM Conor Dooley <[email protected]> wrote:
>
> On Mon, Jan 22, 2024 at 09:35:10AM +0800, Yunhui Cui wrote:
> > When cacheinfo_sysfs_init() is executed, the general weak function
> > init_cache_level() returns -ENOENT, causing failure to add the "cache"
> > node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
> > function on RISC-V to fix it.
>
> If you recall correctly, I asked you to explain how to reproduce this
> when you sent the patch.
In fact, the reason has been explained in the commit log. As for how
to reproduce it, you can check whether there is a "cache" node in
/sys/devices/system/cpu/cpux/ on the riscv platform.
Thanks,
Yunhui
On Mon, Jan 22, 2024 at 04:32:15PM +0800, yunhui cui wrote:
> Hi Conor,
>
> On Mon, Jan 22, 2024 at 4:09 PM Conor Dooley <[email protected]> wrote:
> >
> > On Mon, Jan 22, 2024 at 09:35:10AM +0800, Yunhui Cui wrote:
> > > When cacheinfo_sysfs_init() is executed, the general weak function
> > > init_cache_level() returns -ENOENT, causing failure to add the "cache"
> > > node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
> > > function on RISC-V to fix it.
> >
> > If you recall correctly, I asked you to explain how to reproduce this
> > when you sent the patch.
>
> In fact, the reason has been explained in the commit log. As for how
> to reproduce it, you can check whether there is a "cache" node in
> /sys/devices/system/cpu/cpux/ on the riscv platform.
That's the thing - I tried to reproduce this several times and either:
a) The system had cache information in DT and the directory was
created. If I hot unplugged and re-plugged the directory was
re-created.
b) The system had no cache information in DT and the directory was never
created.
You said in your original report that you came across this problem in
qemu - can you share the qemu command required to reproduce please?
Thanks,
Conor.
Hi Conor,
On Mon, Jan 22, 2024 at 4:55 PM Conor Dooley <[email protected]> wrote:
>
> On Mon, Jan 22, 2024 at 04:32:15PM +0800, yunhui cui wrote:
> > Hi Conor,
> >
> > On Mon, Jan 22, 2024 at 4:09 PM Conor Dooley <[email protected]> wrote:
> > >
> > > On Mon, Jan 22, 2024 at 09:35:10AM +0800, Yunhui Cui wrote:
> > > > When cacheinfo_sysfs_init() is executed, the general weak function
> > > > init_cache_level() returns -ENOENT, causing failure to add the "cache"
> > > > node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
> > > > function on RISC-V to fix it.
> > >
> > > If you recall correctly, I asked you to explain how to reproduce this
> > > when you sent the patch.
> >
> > In fact, the reason has been explained in the commit log. As for how
> > to reproduce it, you can check whether there is a "cache" node in
> > /sys/devices/system/cpu/cpux/ on the riscv platform.
>
> That's the thing - I tried to reproduce this several times and either:
> a) The system had cache information in DT and the directory was
> created. If I hot unplugged and re-plugged the directory was
> re-created.
> b) The system had no cache information in DT and the directory was never
> created.
Indeed, I verified it again, it’s because there is no cache node in
dts, thank you for reminding me.
Thanks,
Yunhui
On Mon, Jan 22, 2024 at 06:57:49PM +0800, yunhui cui wrote:
> Hi Conor,
>
> On Mon, Jan 22, 2024 at 4:55 PM Conor Dooley <[email protected]> wrote:
> >
> > On Mon, Jan 22, 2024 at 04:32:15PM +0800, yunhui cui wrote:
> > > Hi Conor,
> > >
> > > On Mon, Jan 22, 2024 at 4:09 PM Conor Dooley <[email protected]> wrote:
> > > >
> > > > On Mon, Jan 22, 2024 at 09:35:10AM +0800, Yunhui Cui wrote:
> > > > > When cacheinfo_sysfs_init() is executed, the general weak function
> > > > > init_cache_level() returns -ENOENT, causing failure to add the "cache"
> > > > > node to /sys/devices/system/cpu/cpux/. Implement the init_cache_level()
> > > > > function on RISC-V to fix it.
> > > >
> > > > If you recall correctly, I asked you to explain how to reproduce this
> > > > when you sent the patch.
> > >
> > > In fact, the reason has been explained in the commit log. As for how
> > > to reproduce it, you can check whether there is a "cache" node in
> > > /sys/devices/system/cpu/cpux/ on the riscv platform.
> >
> > That's the thing - I tried to reproduce this several times and either:
> > a) The system had cache information in DT and the directory was
> > created. If I hot unplugged and re-plugged the directory was
> > re-created.
> > b) The system had no cache information in DT and the directory was never
> > created.
>
> Indeed, I verified it again, it’s because there is no cache node in
> dts, thank you for reminding me.
>
That's good. I wasn't able to figure out why the issue could occur without
issues in DT/ACPI.
--
Regards,
Sudeep