| Message ID | 1456340856-3065-2-git-send-email-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 24 Feb 2016, Andrew Cooper wrote: > The entire contents of .lockprofile.data are unchanging pointers to > lock_profile structure in .data. Annotate the type as such, and link the > section in .rodata. As these are just pointers, 32byte alignment is > unnecessary. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > --- > CC: Jan Beulich <JBeulich@suse.com> > CC: Ian Campbell <ian.campbell@citrix.com> > CC: Stefano Stabellini <stefano.stabellini@citrix.com> > > v2: > * New > v3: > * Explicitly introduce POINTER_ALIGN to avoid forcing 8 byte alignment on > arm32 Actually the way it is done in this patch, POINTER_ALIGN is 8 on arm64 and 4 on arm32 (see the definition of LONG_BYTEORDER in config.h). But I think it should still be OK. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > xen/arch/arm/xen.lds.S | 15 ++++++++------- > xen/arch/x86/xen.lds.S | 14 +++++++------- > xen/include/asm-arm/config.h | 1 + > xen/include/asm-x86/config.h | 1 + > xen/include/xen/spinlock.h | 2 +- > 5 files changed, 18 insertions(+), 15 deletions(-) > > diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S > index f501a2f..1b5e516 100644 > --- a/xen/arch/arm/xen.lds.S > +++ b/xen/arch/arm/xen.lds.S > @@ -50,6 +50,14 @@ SECTIONS > __stop_bug_frames_2 = .; > *(.rodata) > *(.rodata.*) > + > +#ifdef LOCK_PROFILE > + . = ALIGN(POINTER_ALIGN); > + __lock_profile_start = .; > + *(.lockprofile.data) > + __lock_profile_end = .; > +#endif > + > _erodata = .; /* End of read-only data */ > } :text > > @@ -83,13 +91,6 @@ SECTIONS > *(.data.rel.ro.*) > } :text > > -#ifdef LOCK_PROFILE > - . = ALIGN(32); > - __lock_profile_start = .; > - .lockprofile.data : { *(.lockprofile.data) } :text > - __lock_profile_end = .; > -#endif > - > . = ALIGN(8); > .arch.info : { > _splatform = .; > diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S > index 9fde1db..8390ec2 100644 > --- a/xen/arch/x86/xen.lds.S > +++ b/xen/arch/x86/xen.lds.S > @@ -65,6 +65,13 @@ SECTIONS > > *(.rodata) > *(.rodata.*) > + > +#ifdef LOCK_PROFILE > + . = ALIGN(POINTER_ALIGN); > + __lock_profile_start = .; > + *(.lockprofile.data) > + __lock_profile_end = .; > +#endif > } :text > > . = ALIGN(SMP_CACHE_BYTES); > @@ -97,13 +104,6 @@ SECTIONS > CONSTRUCTORS > } :text > > -#ifdef LOCK_PROFILE > - . = ALIGN(32); > - __lock_profile_start = .; > - .lockprofile.data : { *(.lockprofile.data) } :text > - __lock_profile_end = .; > -#endif > - > . = ALIGN(PAGE_SIZE); /* Init code and data */ > __init_begin = .; > .init.text : { > diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h > index c3a2c30..c0ad469 100644 > --- a/xen/include/asm-arm/config.h > +++ b/xen/include/asm-arm/config.h > @@ -15,6 +15,7 @@ > > #define BYTES_PER_LONG (1 << LONG_BYTEORDER) > #define BITS_PER_LONG (BYTES_PER_LONG << 3) > +#define POINTER_ALIGN BYTES_PER_LONG > > /* xen_ulong_t is always 64 bits */ > #define BITS_PER_XEN_ULONG 64 > diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h > index 07f3c1f..7291b59 100644 > --- a/xen/include/asm-x86/config.h > +++ b/xen/include/asm-x86/config.h > @@ -13,6 +13,7 @@ > #define BYTES_PER_LONG (1 << LONG_BYTEORDER) > #define BITS_PER_LONG (BYTES_PER_LONG << 3) > #define BITS_PER_BYTE 8 > +#define POINTER_ALIGN BYTES_PER_LONG > > #define BITS_PER_XEN_ULONG BITS_PER_LONG > > diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h > index 77ab7d5..88b53f9 100644 > --- a/xen/include/xen/spinlock.h > +++ b/xen/include/xen/spinlock.h > @@ -79,7 +79,7 @@ struct lock_profile_qhead { > > #define _LOCK_PROFILE(name) { 0, #name, &name, 0, 0, 0, 0, 0 } > #define _LOCK_PROFILE_PTR(name) \ > - static struct lock_profile *__lock_profile_##name \ > + static struct lock_profile * const __lock_profile_##name \ > __used_section(".lockprofile.data") = \ > &__lock_profile_data_##name > #define _SPIN_LOCK_UNLOCKED(x) { { 0 }, SPINLOCK_NO_CPU, 0, _LOCK_DEBUG, x } > -- > 2.1.4 >
On Thu, 25 Feb 2016, Stefano Stabellini wrote: > On Wed, 24 Feb 2016, Andrew Cooper wrote: > > The entire contents of .lockprofile.data are unchanging pointers to > > lock_profile structure in .data. Annotate the type as such, and link the > > section in .rodata. As these are just pointers, 32byte alignment is > > unnecessary. > > > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > > --- > > CC: Jan Beulich <JBeulich@suse.com> > > CC: Ian Campbell <ian.campbell@citrix.com> > > CC: Stefano Stabellini <stefano.stabellini@citrix.com> > > > > v2: > > * New > > v3: > > * Explicitly introduce POINTER_ALIGN to avoid forcing 8 byte alignment on > > arm32 > > Actually the way it is done in this patch, POINTER_ALIGN is 8 on arm64 > and 4 on arm32 (see the definition of LONG_BYTEORDER in config.h). I misread the sentence in the commit message, everything good then :-) > But I think it should still be OK. > > Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > > > xen/arch/arm/xen.lds.S | 15 ++++++++------- > > xen/arch/x86/xen.lds.S | 14 +++++++------- > > xen/include/asm-arm/config.h | 1 + > > xen/include/asm-x86/config.h | 1 + > > xen/include/xen/spinlock.h | 2 +- > > 5 files changed, 18 insertions(+), 15 deletions(-) > > > > diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S > > index f501a2f..1b5e516 100644 > > --- a/xen/arch/arm/xen.lds.S > > +++ b/xen/arch/arm/xen.lds.S > > @@ -50,6 +50,14 @@ SECTIONS > > __stop_bug_frames_2 = .; > > *(.rodata) > > *(.rodata.*) > > + > > +#ifdef LOCK_PROFILE > > + . = ALIGN(POINTER_ALIGN); > > + __lock_profile_start = .; > > + *(.lockprofile.data) > > + __lock_profile_end = .; > > +#endif > > + > > _erodata = .; /* End of read-only data */ > > } :text > > > > @@ -83,13 +91,6 @@ SECTIONS > > *(.data.rel.ro.*) > > } :text > > > > -#ifdef LOCK_PROFILE > > - . = ALIGN(32); > > - __lock_profile_start = .; > > - .lockprofile.data : { *(.lockprofile.data) } :text > > - __lock_profile_end = .; > > -#endif > > - > > . = ALIGN(8); > > .arch.info : { > > _splatform = .; > > diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S > > index 9fde1db..8390ec2 100644 > > --- a/xen/arch/x86/xen.lds.S > > +++ b/xen/arch/x86/xen.lds.S > > @@ -65,6 +65,13 @@ SECTIONS > > > > *(.rodata) > > *(.rodata.*) > > + > > +#ifdef LOCK_PROFILE > > + . = ALIGN(POINTER_ALIGN); > > + __lock_profile_start = .; > > + *(.lockprofile.data) > > + __lock_profile_end = .; > > +#endif > > } :text > > > > . = ALIGN(SMP_CACHE_BYTES); > > @@ -97,13 +104,6 @@ SECTIONS > > CONSTRUCTORS > > } :text > > > > -#ifdef LOCK_PROFILE > > - . = ALIGN(32); > > - __lock_profile_start = .; > > - .lockprofile.data : { *(.lockprofile.data) } :text > > - __lock_profile_end = .; > > -#endif > > - > > . = ALIGN(PAGE_SIZE); /* Init code and data */ > > __init_begin = .; > > .init.text : { > > diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h > > index c3a2c30..c0ad469 100644 > > --- a/xen/include/asm-arm/config.h > > +++ b/xen/include/asm-arm/config.h > > @@ -15,6 +15,7 @@ > > > > #define BYTES_PER_LONG (1 << LONG_BYTEORDER) > > #define BITS_PER_LONG (BYTES_PER_LONG << 3) > > +#define POINTER_ALIGN BYTES_PER_LONG > > > > /* xen_ulong_t is always 64 bits */ > > #define BITS_PER_XEN_ULONG 64 > > diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h > > index 07f3c1f..7291b59 100644 > > --- a/xen/include/asm-x86/config.h > > +++ b/xen/include/asm-x86/config.h > > @@ -13,6 +13,7 @@ > > #define BYTES_PER_LONG (1 << LONG_BYTEORDER) > > #define BITS_PER_LONG (BYTES_PER_LONG << 3) > > #define BITS_PER_BYTE 8 > > +#define POINTER_ALIGN BYTES_PER_LONG > > > > #define BITS_PER_XEN_ULONG BITS_PER_LONG > > > > diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h > > index 77ab7d5..88b53f9 100644 > > --- a/xen/include/xen/spinlock.h > > +++ b/xen/include/xen/spinlock.h > > @@ -79,7 +79,7 @@ struct lock_profile_qhead { > > > > #define _LOCK_PROFILE(name) { 0, #name, &name, 0, 0, 0, 0, 0 } > > #define _LOCK_PROFILE_PTR(name) \ > > - static struct lock_profile *__lock_profile_##name \ > > + static struct lock_profile * const __lock_profile_##name \ > > __used_section(".lockprofile.data") = \ > > &__lock_profile_data_##name > > #define _SPIN_LOCK_UNLOCKED(x) { { 0 }, SPINLOCK_NO_CPU, 0, _LOCK_DEBUG, x } > > -- > > 2.1.4 > > >
diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S index f501a2f..1b5e516 100644 --- a/xen/arch/arm/xen.lds.S +++ b/xen/arch/arm/xen.lds.S @@ -50,6 +50,14 @@ SECTIONS __stop_bug_frames_2 = .; *(.rodata) *(.rodata.*) + +#ifdef LOCK_PROFILE + . = ALIGN(POINTER_ALIGN); + __lock_profile_start = .; + *(.lockprofile.data) + __lock_profile_end = .; +#endif + _erodata = .; /* End of read-only data */ } :text @@ -83,13 +91,6 @@ SECTIONS *(.data.rel.ro.*) } :text -#ifdef LOCK_PROFILE - . = ALIGN(32); - __lock_profile_start = .; - .lockprofile.data : { *(.lockprofile.data) } :text - __lock_profile_end = .; -#endif - . = ALIGN(8); .arch.info : { _splatform = .; diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index 9fde1db..8390ec2 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -65,6 +65,13 @@ SECTIONS *(.rodata) *(.rodata.*) + +#ifdef LOCK_PROFILE + . = ALIGN(POINTER_ALIGN); + __lock_profile_start = .; + *(.lockprofile.data) + __lock_profile_end = .; +#endif } :text . = ALIGN(SMP_CACHE_BYTES); @@ -97,13 +104,6 @@ SECTIONS CONSTRUCTORS } :text -#ifdef LOCK_PROFILE - . = ALIGN(32); - __lock_profile_start = .; - .lockprofile.data : { *(.lockprofile.data) } :text - __lock_profile_end = .; -#endif - . = ALIGN(PAGE_SIZE); /* Init code and data */ __init_begin = .; .init.text : { diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h index c3a2c30..c0ad469 100644 --- a/xen/include/asm-arm/config.h +++ b/xen/include/asm-arm/config.h @@ -15,6 +15,7 @@ #define BYTES_PER_LONG (1 << LONG_BYTEORDER) #define BITS_PER_LONG (BYTES_PER_LONG << 3) +#define POINTER_ALIGN BYTES_PER_LONG /* xen_ulong_t is always 64 bits */ #define BITS_PER_XEN_ULONG 64 diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h index 07f3c1f..7291b59 100644 --- a/xen/include/asm-x86/config.h +++ b/xen/include/asm-x86/config.h @@ -13,6 +13,7 @@ #define BYTES_PER_LONG (1 << LONG_BYTEORDER) #define BITS_PER_LONG (BYTES_PER_LONG << 3) #define BITS_PER_BYTE 8 +#define POINTER_ALIGN BYTES_PER_LONG #define BITS_PER_XEN_ULONG BITS_PER_LONG diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h index 77ab7d5..88b53f9 100644 --- a/xen/include/xen/spinlock.h +++ b/xen/include/xen/spinlock.h @@ -79,7 +79,7 @@ struct lock_profile_qhead { #define _LOCK_PROFILE(name) { 0, #name, &name, 0, 0, 0, 0, 0 } #define _LOCK_PROFILE_PTR(name) \ - static struct lock_profile *__lock_profile_##name \ + static struct lock_profile * const __lock_profile_##name \ __used_section(".lockprofile.data") = \ &__lock_profile_data_##name #define _SPIN_LOCK_UNLOCKED(x) { { 0 }, SPINLOCK_NO_CPU, 0, _LOCK_DEBUG, x }
The entire contents of .lockprofile.data are unchanging pointers to lock_profile structure in .data. Annotate the type as such, and link the section in .rodata. As these are just pointers, 32byte alignment is unnecessary. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Stefano Stabellini <stefano.stabellini@citrix.com> v2: * New v3: * Explicitly introduce POINTER_ALIGN to avoid forcing 8 byte alignment on arm32 --- xen/arch/arm/xen.lds.S | 15 ++++++++------- xen/arch/x86/xen.lds.S | 14 +++++++------- xen/include/asm-arm/config.h | 1 + xen/include/asm-x86/config.h | 1 + xen/include/xen/spinlock.h | 2 +- 5 files changed, 18 insertions(+), 15 deletions(-)