| Message ID | 1452288166-43501-4-git-send-email-jonathan.creekmore@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/01/16 21:22, Jonathan Creekmore wrote: > Creates a section to contain scheduler entry pointers that are gathered > together into an array. This will allow, in a follow-on patch, scheduler > entries to be automatically gathered together into the array for > automatic parsing. > > CC: Ian Campbell <ian.campbell@citrix.com> > CC: Stefano Stabellini <stefano.stabellini@citrix.com> > CC: Keir Fraser <keir@xen.org> > CC: Jan Beulich <jbeulich@suse.com> > CC: Andrew Cooper <andrew.cooper3@citrix.com> > Signed-off-by: Jonathan Creekmore <jonathan.creekmore@gmail.com> > Reviewed-by: Doug Goldstein <cardoe@cardoe.com> > > --- > Changed since v3: > * Add defensive check for schedulers in the linker > > Changed since v1: > * rename the __start and __end symbols to better match > the rest of the file > --- > xen/arch/arm/xen.lds.S | 5 +++++ > xen/arch/x86/xen.lds.S | 5 +++++ > 2 files changed, 10 insertions(+) > > diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S > index 0488f37..2492def 100644 > --- a/xen/arch/arm/xen.lds.S > +++ b/xen/arch/arm/xen.lds.S > @@ -57,6 +57,10 @@ SECTIONS > . = ALIGN(PAGE_SIZE); > *(.data.page_aligned) > *(.data) > + . = ALIGN(8); > + __start_schedulers_array = .; > + *(.data.schedulers) > + __end_schedulers_array = .; > *(.data.rel) > *(.data.rel.*) > CONSTRUCTORS > @@ -193,3 +197,4 @@ SECTIONS > * code running on the boot time identity map cannot cross a section boundary. > */ > ASSERT( _end_boot - start <= PAGE_SIZE, "Boot code is larger than 4K") > +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in") > diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S > index e18e08f..63f89af 100644 > --- a/xen/arch/x86/xen.lds.S > +++ b/xen/arch/x86/xen.lds.S > @@ -80,6 +80,10 @@ SECTIONS > __stop___pre_ex_table = .; > > *(.data.read_mostly) > + . = ALIGN(8); > + __start_schedulers_array = .; > + *(.data.schedulers) > + __end_schedulers_array = .; > *(.data.rel.ro) > *(.data.rel.ro.*) > } :text > @@ -226,3 +230,4 @@ ASSERT(kexec_reloc_size - kexec_reloc <= PAGE_SIZE, "kexec_reloc is too large") > #endif > > ASSERT((cpu0_stack & (STACK_SIZE - 1)) == 0, "cpu0_stack misaligned") > +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in") This patch won't build on its own, as the ASSERT() will fire. Therefore, it breaks bisectability. In this patch (or the previous one), you need to move the schedulers list into __section(".data.schedulers"), and undo the movement in patch 4 when populating .data.schedulers properly. Alternatively, you could just merge patches 3 and 4. I don't think that would reduce the clarity of what you were doing. ~Andrew
Andrew Cooper writes: > On 08/01/16 21:22, Jonathan Creekmore wrote: >> Creates a section to contain scheduler entry pointers that are gathered >> together into an array. This will allow, in a follow-on patch, scheduler >> entries to be automatically gathered together into the array for >> automatic parsing. >> >> CC: Ian Campbell <ian.campbell@citrix.com> >> CC: Stefano Stabellini <stefano.stabellini@citrix.com> >> CC: Keir Fraser <keir@xen.org> >> CC: Jan Beulich <jbeulich@suse.com> >> CC: Andrew Cooper <andrew.cooper3@citrix.com> >> Signed-off-by: Jonathan Creekmore <jonathan.creekmore@gmail.com> >> Reviewed-by: Doug Goldstein <cardoe@cardoe.com> >> >> --- >> Changed since v3: >> * Add defensive check for schedulers in the linker >> >> Changed since v1: >> * rename the __start and __end symbols to better match >> the rest of the file >> --- >> xen/arch/arm/xen.lds.S | 5 +++++ >> xen/arch/x86/xen.lds.S | 5 +++++ >> 2 files changed, 10 insertions(+) >> >> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S >> index 0488f37..2492def 100644 >> --- a/xen/arch/arm/xen.lds.S >> +++ b/xen/arch/arm/xen.lds.S >> @@ -57,6 +57,10 @@ SECTIONS >> . = ALIGN(PAGE_SIZE); >> *(.data.page_aligned) >> *(.data) >> + . = ALIGN(8); >> + __start_schedulers_array = .; >> + *(.data.schedulers) >> + __end_schedulers_array = .; >> *(.data.rel) >> *(.data.rel.*) >> CONSTRUCTORS >> @@ -193,3 +197,4 @@ SECTIONS >> * code running on the boot time identity map cannot cross a section boundary. >> */ >> ASSERT( _end_boot - start <= PAGE_SIZE, "Boot code is larger than 4K") >> +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in") >> diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S >> index e18e08f..63f89af 100644 >> --- a/xen/arch/x86/xen.lds.S >> +++ b/xen/arch/x86/xen.lds.S >> @@ -80,6 +80,10 @@ SECTIONS >> __stop___pre_ex_table = .; >> >> *(.data.read_mostly) >> + . = ALIGN(8); >> + __start_schedulers_array = .; >> + *(.data.schedulers) >> + __end_schedulers_array = .; >> *(.data.rel.ro) >> *(.data.rel.ro.*) >> } :text >> @@ -226,3 +230,4 @@ ASSERT(kexec_reloc_size - kexec_reloc <= PAGE_SIZE, "kexec_reloc is too large") >> #endif >> >> ASSERT((cpu0_stack & (STACK_SIZE - 1)) == 0, "cpu0_stack misaligned") >> +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in") > > This patch won't build on its own, as the ASSERT() will fire. > Therefore, it breaks bisectability. > > In this patch (or the previous one), you need to move the schedulers > list into __section(".data.schedulers"), and undo the movement in patch > 4 when populating .data.schedulers properly. > > Alternatively, you could just merge patches 3 and 4. I don't think that > would reduce the clarity of what you were doing. Quite right. I think merging patches 3 and 4 is probably the most straightforward way. That way, one patch introduces the new section and actually populates that section.
diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S index 0488f37..2492def 100644 --- a/xen/arch/arm/xen.lds.S +++ b/xen/arch/arm/xen.lds.S @@ -57,6 +57,10 @@ SECTIONS . = ALIGN(PAGE_SIZE); *(.data.page_aligned) *(.data) + . = ALIGN(8); + __start_schedulers_array = .; + *(.data.schedulers) + __end_schedulers_array = .; *(.data.rel) *(.data.rel.*) CONSTRUCTORS @@ -193,3 +197,4 @@ SECTIONS * code running on the boot time identity map cannot cross a section boundary. */ ASSERT( _end_boot - start <= PAGE_SIZE, "Boot code is larger than 4K") +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in") diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index e18e08f..63f89af 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -80,6 +80,10 @@ SECTIONS __stop___pre_ex_table = .; *(.data.read_mostly) + . = ALIGN(8); + __start_schedulers_array = .; + *(.data.schedulers) + __end_schedulers_array = .; *(.data.rel.ro) *(.data.rel.ro.*) } :text @@ -226,3 +230,4 @@ ASSERT(kexec_reloc_size - kexec_reloc <= PAGE_SIZE, "kexec_reloc is too large") #endif ASSERT((cpu0_stack & (STACK_SIZE - 1)) == 0, "cpu0_stack misaligned") +ASSERT((__end_schedulers_array - __start_schedulers_array) > 0, "no schedulers compiled in")