search for: alternative_instruct

....h> +#include <asm/processor.h> +#include <asm/i387.h> +#include <asm/msr.h> +#include <asm/pda.h> + +void __init check_bugs(void) +{ + identify_cpu(&boot_cpu_data); +#if !defined(CONFIG_SMP) + printk("CPU: "); + print_cpu_info(&boot_cpu_data); +#endif + alternative_instructions(); +} =================================================================== --- a/include/asm-x86_64/alternative.h +++ b/include/asm-x86_64/alternative.h @@ -16,6 +16,7 @@ struct alt_instr { u8 pad[5]; }; +extern void alternative_instructions(void); extern void apply_alternatives(struct al...

....h> +#include <asm/processor.h> +#include <asm/i387.h> +#include <asm/msr.h> +#include <asm/pda.h> + +void __init check_bugs(void) +{ + identify_cpu(&boot_cpu_data); +#if !defined(CONFIG_SMP) + printk("CPU: "); + print_cpu_info(&boot_cpu_data); +#endif + alternative_instructions(); +} =================================================================== --- a/include/asm-x86_64/alternative.h +++ b/include/asm-x86_64/alternative.h @@ -16,6 +16,7 @@ struct alt_instr { u8 pad[5]; }; +extern void alternative_instructions(void); extern void apply_alternatives(struct al...

...er_ that, the kernel_init is called and that in turn does the smp_prepare_cpus which now changes the pv_lock_ops again, *but not* run any patching again. So the _raw_spin_*lock calls still use the ticket calls. start_kernel setup_arch -> xen_hvm_smp_init (set smp_ops) ... check_bugs -> alternative_instructions (patches pv_locks sites) ... rest_init (triggers kernel_init as a thread) kernel_init ... smp_prepare_cpus (calls xen_init_spinlocks through smp_ops hook) To make things even more fun, there is the possibility that some spinlock functions are forced to be inlined and others...

...chary Amsden <zach@vmware.com> diff -r 773ac0ebfeb4 arch/i386/kernel/alternative.c --- a/arch/i386/kernel/alternative.c Wed Oct 18 06:03:56 2006 -0700 +++ b/arch/i386/kernel/alternative.c Wed Oct 18 06:07:03 2006 -0700 @@ -344,6 +344,7 @@ void alternatives_smp_switch(int smp) void __init alternative_instructions(void) { + unsigned long flags; if (no_replacement) { printk(KERN_INFO "(SMP-)alternatives turned off\n"); free_init_pages("SMP alternatives", @@ -351,6 +352,8 @@ void __init alternative_instructions(voi (unsigned long)__smp_alt_end); return; } + + local_ir...

...chary Amsden <zach@vmware.com> diff -r 773ac0ebfeb4 arch/i386/kernel/alternative.c --- a/arch/i386/kernel/alternative.c Wed Oct 18 06:03:56 2006 -0700 +++ b/arch/i386/kernel/alternative.c Wed Oct 18 06:07:03 2006 -0700 @@ -344,6 +344,7 @@ void alternatives_smp_switch(int smp) void __init alternative_instructions(void) { + unsigned long flags; if (no_replacement) { printk(KERN_INFO "(SMP-)alternatives turned off\n"); free_init_pages("SMP alternatives", @@ -351,6 +352,8 @@ void __init alternative_instructions(voi (unsigned long)__smp_alt_end); return; } + + local_ir...

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

Hi Andi, Here's a little batch of cleanups: - re-enable VDSO when PARAVIRT is enabled - make the parainstructions symbols match the other altinstructions naming convention - add kernel command-line options to disable altinstructions for smp and pv_ops Oh, and I'm mailing your noreplacement patch back at you, for no particularly good reason. J --

On 03/16/2015 09:16 AM, Peter Zijlstra wrote: > Implement the paravirt qspinlock for x86-kvm. > > We use the regular paravirt call patching to switch between: > > native_queue_spin_lock_slowpath() __pv_queue_spin_lock_slowpath() > native_queue_spin_unlock() __pv_queue_spin_unlock() > > We use a callee saved call for the unlock function which reduces the > i-cache

On 03/16/2015 09:16 AM, Peter Zijlstra wrote: > Implement the paravirt qspinlock for x86-kvm. > > We use the regular paravirt call patching to switch between: > > native_queue_spin_lock_slowpath() __pv_queue_spin_lock_slowpath() > native_queue_spin_unlock() __pv_queue_spin_unlock() > > We use a callee saved call for the unlock function which reduces the > i-cache

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

...dom location. I believe that was causing the system > panic that I saw. > > So I think it is kind of risky to use it here unless we can guarantee that > call site patching is atomic wrt other CPUs. Just look at where the patching is done: init/main.c:start_kernel() check_bugs() alternative_instructions() apply_paravirt() We're UP and not holding any locks, disable IRQs (see text_poke_early()) and have NMIs 'disabled'.

...the system >> panic that I saw. >> >> So I think it is kind of risky to use it here unless we can guarantee that >> call site patching is atomic wrt other CPUs. > Just look at where the patching is done: > > init/main.c:start_kernel() > check_bugs() > alternative_instructions() > apply_paravirt() > > We're UP and not holding any locks, disable IRQs (see text_poke_early()) > and have NMIs 'disabled'. You are probably right. The initial apply_paravirt() was done before the SMP boot. Subsequent ones were at kernel module load time. I pu...

...dom location. I believe that was causing the system > panic that I saw. > > So I think it is kind of risky to use it here unless we can guarantee that > call site patching is atomic wrt other CPUs. Just look at where the patching is done: init/main.c:start_kernel() check_bugs() alternative_instructions() apply_paravirt() We're UP and not holding any locks, disable IRQs (see text_poke_early()) and have NMIs 'disabled'.

...the system >> panic that I saw. >> >> So I think it is kind of risky to use it here unless we can guarantee that >> call site patching is atomic wrt other CPUs. > Just look at where the patching is done: > > init/main.c:start_kernel() > check_bugs() > alternative_instructions() > apply_paravirt() > > We're UP and not holding any locks, disable IRQs (see text_poke_early()) > and have NMIs 'disabled'. You are probably right. The initial apply_paravirt() was done before the SMP boot. Subsequent ones were at kernel module load time. I pu...

This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality. The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler

This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality. The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler

...+ } +} +extern struct paravirt_patch __start_parainstructions[], + __stop_parainstructions[]; +#else +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) +{ +} +extern char __start_parainstructions[], __stop_parainstructions[]; +#endif /* CONFIG_PARAVIRT */ + void __init alternative_instructions(void) { apply_alternatives(__alt_instructions, __alt_instructions_end); @@ -318,4 +354,6 @@ void __init alternative_instructions(voi _text, _etext); alternatives_smp_switch(0); } + + apply_paravirt(__start_parainstructions, __stop_parainstructions); } diff -urpN --exclude TAG...

...+ } +} +extern struct paravirt_patch __start_parainstructions[], + __stop_parainstructions[]; +#else +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) +{ +} +extern char __start_parainstructions[], __stop_parainstructions[]; +#endif /* CONFIG_PARAVIRT */ + void __init alternative_instructions(void) { apply_alternatives(__alt_instructions, __alt_instructions_end); @@ -318,4 +354,6 @@ void __init alternative_instructions(voi _text, _etext); alternatives_smp_switch(0); } + + apply_paravirt(__start_parainstructions, __stop_parainstructions); } diff -urpN --exclude TAG...

...define new_len2 145f-144f diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index c096624137ae..8482f90d5078 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -61,6 +61,7 @@ extern int alternatives_patched; extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); +extern void apply_pv_alternatives(void); struct module; @@ -132,14 +133,17 @@ static inline int alternatives_text_reserved(void *start, void *end) b_replacement(num)":\n\t" newinstr "\...