search for: check_bugs

...lucky if pv spinlocks in HVM worked for anybody. The xen_hvm_smp_init() call will change the smp_ops hooks. One of which is smp_prepare_cpus. This is done in start_kernel and at this point in time, there is no change to the pv_lock_ops and they point to the ticket versions. Later in start_kernel, check_bugs is called and part of that takes the pv_lock_ops and patches the kernel with the correct jumps. _After_ 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 ti...

...===================== --- /dev/null +++ b/arch/x86_64/kernel/bugs.c @@ -0,0 +1,28 @@ +/* + * arch/x86_64/kernel/bugs.c + * + * Copyright (C) 1994 Linus Torvalds + * Copyright (C) 2000 SuSE + * + * This is included by init/main.c to check for architecture-dependent bugs. + * + * Needs: + * void check_bugs(void); + */ + +#include <linux/kernel.h> +#include <asm/alternative.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)...

...===================== --- /dev/null +++ b/arch/x86_64/kernel/bugs.c @@ -0,0 +1,28 @@ +/* + * arch/x86_64/kernel/bugs.c + * + * Copyright (C) 1994 Linus Torvalds + * Copyright (C) 2000 SuSE + * + * This is included by init/main.c to check for architecture-dependent bugs. + * + * Needs: + * void check_bugs(void); + */ + +#include <linux/kernel.h> +#include <asm/alternative.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)...

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 --

...hen jump to a random 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'.

...elieve 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'. You are probably right. The initial apply_paravirt() was done before the SMP boot. Subsequent ones were...

...hen jump to a random 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'.

...elieve 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'. You are probably right. The initial apply_paravirt() was done before the SMP boot. Subsequent ones were...

...d: 1, comm: swapper/0 Not tainted 3.2.0-4-amd64 #1 Debian 3.2.35-2 [ 0.016224] Call Trace: [ 0.016257] [<ffffffff81046a75>] ? warn_slowpath_common+0x78/0x8c [ 0.016289] [<ffffffff816b2f72>] ? init_hw_perf_events+0x246/0x3e1 [ 0.016319] [<ffffffff816b2d2c>] ? check_bugs+0x2b/0x2b [ 0.016351] [<ffffffff81002085>] ? do_one_initcall+0x75/0x12c [ 0.016383] [<ffffffff816abbcb>] ? kernel_init+0x8d/0x152 [ 0.016414] [<ffffffff81354174>] ? kernel_thread_helper+0x4/0x10 [ 0.016447] [<ffffffff81352233>] ? int_ret_from_sys_call...

...t sysenter_setup(void) { void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC); syscall_pages[0] = virt_to_page(syscall_page); =================================================================== --- a/arch/x86_64/kernel/bugs.c +++ b/arch/x86_64/kernel/bugs.c @@ -19,7 +19,7 @@ void __init check_bugs(void) { - identify_cpu(&boot_cpu_data); + identify_boot_cpu(); #if !defined(CONFIG_SMP) printk("CPU: "); print_cpu_info(&boot_cpu_data); =================================================================== --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -...

...t sysenter_setup(void) { void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC); syscall_pages[0] = virt_to_page(syscall_page); =================================================================== --- a/arch/x86_64/kernel/bugs.c +++ b/arch/x86_64/kernel/bugs.c @@ -19,7 +19,7 @@ void __init check_bugs(void) { - identify_cpu(&boot_cpu_data); + identify_boot_cpu(); #if !defined(CONFIG_SMP) printk("CPU: "); print_cpu_info(&boot_cpu_data); =================================================================== --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -...

...ug detected - turning on workaround.\n"); + pentium_f00f_bug = 1; + trap_init_f00f_bug(); + } else { + printk(KERN_INFO " no F0 0F bug in this CPU, great!\n"); + pentium_f00f_bug = 0; + } +} + __initfunc(static void check_bugs(void)) { check_tlb(); @@ -173,5 +199,6 @@ check_hlt(); check_popad(); check_amd_k6(); + check_pentium_f00f(); system_utsname.machine[1] = ''0'' + x86; } ------- end -------

Hi Andi, This is a set of updates for the firstfloor patch queue. Quick rundown: revert-mm-x86_64-mm-account-for-module-percpu-space-separately-from-kernel-percpu.patch separate-module-percpu-space.patch Update the module percpu accounting patch fix-ff-allow-percpu-variables-to-be-page-aligned.patch Make sure the percpu memory allocation is page-aligned

Hi Andi, This is a set of updates for the firstfloor patch queue. Quick rundown: revert-mm-x86_64-mm-account-for-module-percpu-space-separately-from-kernel-percpu.patch separate-module-percpu-space.patch Update the module percpu accounting patch fix-ff-allow-percpu-variables-to-be-page-aligned.patch Make sure the percpu memory allocation is page-aligned

...ot_cold_page+0x106/0x160 [ 110.721000] [<ffffffffad99bc6d>] ? adjust_managed_page_count+0x5d/0x80 [ 110.721000] [<ffffffffad86fc6a>] ? free_init_pages+0x15a/0x1b0 [ 110.721000] [<ffffffffae579537>] alternative_instructions+0xc3/0xca [ 110.721000] [<ffffffffae57b0cb>] check_bugs+0x25f/0x2b6 [ 110.721000] [<ffffffffae56c19d>] start_kernel+0x422/0x46c [ 110.721000] [<ffffffffae56bb7b>] ? repair_env_string+0x5c/0x5c [ 110.721000] [<ffffffffae56b120>] ? early_idt_handler_array+0x120/0x120 [ 110.721000] [<ffffffffae56b72f>] x86_64_start_reservati...

...04000] [<c1037799>] ? warn_slowpath_common+0x5e/0x8a [ 0.004000] [<c10377cf>] ? warn_slowpath_null+0xa/0xc [ 0.004000] [<c1011cdc>] ? perf_events_lapic_init+0x28/0x29 [ 0.004000] [<c14073d9>] ? init_hw_perf_events+0x2dd/0x376 [ 0.004000] [<c140702c>] ? check_bugs+0x8/0xd8 [ 0.004000] [<c13ff808>] ? start_kernel+0x309/0x31d [ 0.004000] [<c1401410>] ? xen_start_kernel+0x564/0x56b [ 0.004000] [<c1409046>] ? mtrr_cleanup+0x341/0x3eb [ 0.004000] ---[ end trace a7919e7f17c0a725 ]--- [ 0.004000] ... version: 0 [...

...i [ 0.005879] Modules linked in: [ 0.005885] Pid: 0, comm: swapper Not tainted 2.6.32.26 #7 [ 0.005890] Call Trace: [ 0.005898] [] ? warn_slowpath_common+0x76/0x8c [ 0.005905] [] ? init_hw_perf_events+0x337/0x3d7 [ 0.005912] [] ? identify_boot_cpu+0x15/0x3d [ 0.005918] [] ? check_bugs+0x9/0x2e [ 0.005924] [] ? start_kernel+0x3cb/0x3e5 [ 0.005931] [] ? xen_start_kernel+0x5a4/0x5a8 [ 0.005941] ---[ end trace a7919e7f17c0a725 ]--- [ 0.005946] ... version: 0 [ 0.005950] ... bit width: 48 [ 0.005953] ... generic registers: 4 [ 0...