* [PATCH v1] hyperv: reduce size of ms_hyperv_info
@ 2023-09-18 16:01 Olaf Hering
2023-09-19 6:18 ` Dexuan Cui
0 siblings, 1 reply; 4+ messages in thread
From: Olaf Hering @ 2023-09-18 16:01 UTC (permalink / raw)
To: linux-hyperv, linux-arch, linux-kernel
Cc: K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
Arnd Bergmann
Use the hole prior shared_gpa_boundary to store the result of get_vtl.
This reduces the size by 8 bytes.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
include/asm-generic/mshyperv.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index cecd2b7bd033..bdee5fbaaf40 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -53,8 +53,8 @@ struct ms_hyperv_info {
u32 reserved_b2 : 20;
};
};
- u64 shared_gpa_boundary;
u8 vtl;
+ u64 shared_gpa_boundary;
};
extern struct ms_hyperv_info ms_hyperv;
extern bool hv_nested;
^ permalink raw reply related [flat|nested] 4+ messages in thread* RE: [PATCH v1] hyperv: reduce size of ms_hyperv_info
2023-09-18 16:01 [PATCH v1] hyperv: reduce size of ms_hyperv_info Olaf Hering
@ 2023-09-19 6:18 ` Dexuan Cui
2023-09-19 7:12 ` Olaf Hering
2023-09-22 18:44 ` Wei Liu
0 siblings, 2 replies; 4+ messages in thread
From: Dexuan Cui @ 2023-09-19 6:18 UTC (permalink / raw)
To: Olaf Hering, linux-hyperv@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: KY Srinivasan, Haiyang Zhang, Wei Liu, Arnd Bergmann
> From: Olaf Hering <olaf@aepfle.de>
> Sent: Monday, September 18, 2023 9:02 AM
> [...]
> Use the hole prior shared_gpa_boundary to store the result of get_vtl.
> This reduces the size by 8 bytes.
> [...]
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -53,8 +53,8 @@ struct ms_hyperv_info {
> u32 reserved_b2 : 20;
> };
> };
> - u64 shared_gpa_boundary;
> u8 vtl;
> + u64 shared_gpa_boundary;
> };
> extern struct ms_hyperv_info ms_hyperv;
> extern bool hv_nested;
How about moving the 'vtl' field to an even earlier place:
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -36,6 +36,9 @@ struct ms_hyperv_info {
u32 nested_features;
u32 max_vp_index;
u32 max_lp_index;
+
+ u8 vtl;
+
union {
u32 isolation_config_a;
struct {
@@ -54,7 +57,6 @@ struct ms_hyperv_info {
};
};
u64 shared_gpa_boundary;
- u8 vtl;
};
extern struct ms_hyperv_info ms_hyperv;
extern bool hv_nested;
This also reduces the size by 8 bytes, and keeps
the isolation_config_a/ isolation_config_b/ shared_gpa_boundary
together, which are related.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v1] hyperv: reduce size of ms_hyperv_info
2023-09-19 6:18 ` Dexuan Cui
@ 2023-09-19 7:12 ` Olaf Hering
2023-09-22 18:44 ` Wei Liu
1 sibling, 0 replies; 4+ messages in thread
From: Olaf Hering @ 2023-09-19 7:12 UTC (permalink / raw)
To: Dexuan Cui
Cc: linux-hyperv@vger.kernel.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org, KY Srinivasan, Haiyang Zhang,
Wei Liu, Arnd Bergmann
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Tue, 19 Sep 2023 06:18:53 +0000 Dexuan Cui <decui@microsoft.com>:
> How about moving the 'vtl' field to an even earlier place:
I have not tried it, but I think this would just move the hole up.
The end result will likely be the same, pahole -E vmlinux will show it.
Olaf
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v1] hyperv: reduce size of ms_hyperv_info
2023-09-19 6:18 ` Dexuan Cui
2023-09-19 7:12 ` Olaf Hering
@ 2023-09-22 18:44 ` Wei Liu
1 sibling, 0 replies; 4+ messages in thread
From: Wei Liu @ 2023-09-22 18:44 UTC (permalink / raw)
To: Dexuan Cui
Cc: Olaf Hering, linux-hyperv@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
KY Srinivasan, Haiyang Zhang, Wei Liu, Arnd Bergmann
On Tue, Sep 19, 2023 at 06:18:53AM +0000, Dexuan Cui wrote:
> > From: Olaf Hering <olaf@aepfle.de>
> > Sent: Monday, September 18, 2023 9:02 AM
> > [...]
> > Use the hole prior shared_gpa_boundary to store the result of get_vtl.
> > This reduces the size by 8 bytes.
> > [...]
> > --- a/include/asm-generic/mshyperv.h
> > +++ b/include/asm-generic/mshyperv.h
> > @@ -53,8 +53,8 @@ struct ms_hyperv_info {
> > u32 reserved_b2 : 20;
> > };
> > };
> > - u64 shared_gpa_boundary;
> > u8 vtl;
> > + u64 shared_gpa_boundary;
> > };
> > extern struct ms_hyperv_info ms_hyperv;
> > extern bool hv_nested;
>
> How about moving the 'vtl' field to an even earlier place:
>
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -36,6 +36,9 @@ struct ms_hyperv_info {
> u32 nested_features;
> u32 max_vp_index;
> u32 max_lp_index;
> +
> + u8 vtl;
> +
> union {
> u32 isolation_config_a;
> struct {
> @@ -54,7 +57,6 @@ struct ms_hyperv_info {
> };
> };
> u64 shared_gpa_boundary;
> - u8 vtl;
> };
> extern struct ms_hyperv_info ms_hyperv;
> extern bool hv_nested;
>
> This also reduces the size by 8 bytes, and keeps
> the isolation_config_a/ isolation_config_b/ shared_gpa_boundary
> together, which are related.
Either method works for me.
Will there be a v2 of this patch?
Thanks,
Wei.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-09-22 18:45 UTC | newest]
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2023-09-18 16:01 [PATCH v1] hyperv: reduce size of ms_hyperv_info Olaf Hering
2023-09-19 6:18 ` Dexuan Cui
2023-09-19 7:12 ` Olaf Hering
2023-09-22 18:44 ` Wei Liu
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