On Wed, Feb 13, 2013 at 9:13 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > Dear RT Folks, > > I'm pleased to announce the 3.6.11-rt29 release. > > Changes since 3.6.11-rt26: > > 1) Fix the RT highmem implementation on x86 this time really. The > issue I was seeing with kmap_atomic and friends was actually > when CONFIG_HIGHMEM was disabled. x8632 uses the atomic maps for > io_mapping_map_atomic_wc() even when CONFIG_HIGHMEM is off. > > 2) Modify the kmap_atomic per thread storage mechanism to reduce > code in switch_to > 3) Rewrite RT highmem support for ARM with the kmap_atomic switch > mechanism like x86_32 uses it. > > This is probably the last release for 3.6 from my side. Steven might > keep it maintained until the 3.8-rt stabilizes, but that's not yet > decided. I happened to notice that there was a misplaced dependency, that had existed long before 3.6 trees. It was meant for RCU's Kconfig item "PREEMPT_RCU" but got accidentally placed under the Kconfig "RT_GROUP_SCHED" option. The fixup can be had by fetching: git://git.kernel.org/pub/scm/linux/kernel/git/paulg/3.6-rt-patches.git on branch "v3.6.11-rt29-fixes", Unless you have been making your own custom kernels, this change probably does not impact you. Thanks, Paul. -- > > The delta patch against 3.6.11-rt28 is appended below and can be found > here: > > http://www.kernel.org/pub/linux/kernel/projects/rt/3.6/incr/patch-3.6.11-rt28-rt29.patch.xz > > The RT patch against 3.6.11 can be found here: > > http://www.kernel.org/pub/linux/kernel/projects/rt/3.6/patch-3.6.11-rt29.patch.xz > > The split quilt queue is available at: > > http://www.kernel.org/pub/linux/kernel/projects/rt/3.6/patches-3.6.11-rt29.tar.xz > > Enjoy, > > tglx > > -------------> > Index: linux-stable/arch/arm/include/asm/highmem.h > =================================================================== > --- linux-stable.orig/arch/arm/include/asm/highmem.h > +++ linux-stable/arch/arm/include/asm/highmem.h > @@ -57,25 +57,10 @@ static inline void *kmap_high_get(struct > #ifdef CONFIG_HIGHMEM > extern void *kmap(struct page *page); > extern void kunmap(struct page *page); > -# ifndef CONFIG_PREEMPT_RT_FULL > extern void *kmap_atomic(struct page *page); > extern void __kunmap_atomic(void *kvaddr); > extern void *kmap_atomic_pfn(unsigned long pfn); > extern struct page *kmap_atomic_to_page(const void *ptr); > -# else > -# define kmap_atomic(page) \ > - ({ pagefault_disable(); kmap(page); }) > - > -# define kmap_atomic_pfn(pfn) \ > - ({ pagefault_disable(); kmap(pfn_to_page(pfn)) }) > - > -# define __kunmap_atomic(kvaddr) \ > - do { kunmap(kmap_to_page(kvaddr)); pagefault_enable(); } while(0) > - > -# define kmap_atomic_to_page(kvaddr) \ > - kmap_to_page(kvaddr) > - > -# endif > #endif > > #endif > Index: linux-stable/arch/arm/mm/highmem.c > =================================================================== > --- linux-stable.orig/arch/arm/mm/highmem.c > +++ linux-stable/arch/arm/mm/highmem.c > @@ -36,9 +36,9 @@ void kunmap(struct page *page) > } > EXPORT_SYMBOL(kunmap); > > -#ifndef CONFIG_PREEMPT_RT_FULL > void *kmap_atomic(struct page *page) > { > + pte_t pte = mk_pte(page, kmap_prot); > unsigned int idx; > unsigned long vaddr; > void *kmap; > @@ -77,7 +77,10 @@ void *kmap_atomic(struct page *page) > * in place, so the contained TLB flush ensures the TLB is updated > * with the new mapping. > */ > - set_top_pte(vaddr, mk_pte(page, kmap_prot)); > +#ifdef CONFIG_PREEMPT_RT_FULL > + current->kmap_pte[type] = pte; > +#endif > + set_top_pte(vaddr, pte); > > return (void *)vaddr; > } > @@ -111,6 +114,7 @@ EXPORT_SYMBOL(__kunmap_atomic); > > void *kmap_atomic_pfn(unsigned long pfn) > { > + pte_t pte = pfn_pte(pfn, kmap_prot); > unsigned long vaddr; > int idx, type; > > @@ -122,7 +126,10 @@ void *kmap_atomic_pfn(unsigned long pfn) > #ifdef CONFIG_DEBUG_HIGHMEM > BUG_ON(!pte_none(get_top_pte(vaddr))); > #endif > - set_top_pte(vaddr, pfn_pte(pfn, kmap_prot)); > +#ifdef CONFIG_PREEMPT_RT_FULL > + current->kmap_pte[type] = pte; > +#endif > + set_top_pte(vaddr, pte); > > return (void *)vaddr; > } > @@ -136,4 +143,28 @@ struct page *kmap_atomic_to_page(const v > > return pte_page(get_top_pte(vaddr)); > } > + > +#if defined CONFIG_PREEMPT_RT_FULL > +void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) > +{ > + int i; > + > + /* > + * Clear @prev's kmap_atomic mappings > + */ > + for (i = 0; i < prev_p->kmap_idx; i++) { > + int idx = i + KM_TYPE_NR * smp_processor_id(); > + > + set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx), __pte(0)); > + } > + /* > + * Restore @next_p's kmap_atomic mappings > + */ > + for (i = 0; i < next_p->kmap_idx; i++) { > + int idx = i + KM_TYPE_NR * smp_processor_id(); > + > + set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx), > + next_p->kmap_pte[i]); > + } > +} > #endif > Index: linux-stable/arch/x86/include/asm/highmem.h > =================================================================== > --- linux-stable.orig/arch/x86/include/asm/highmem.h > +++ linux-stable/arch/x86/include/asm/highmem.h > @@ -56,39 +56,16 @@ extern unsigned long highstart_pfn, high > > extern void *kmap_high(struct page *page); > extern void kunmap_high(struct page *page); > -extern void *kmap_high_prot(struct page *page, pgprot_t prot); > > void *kmap(struct page *page); > void kunmap(struct page *page); > > -#ifndef CONFIG_PREEMPT_RT_FULL > void *kmap_atomic_prot(struct page *page, pgprot_t prot); > void *kmap_atomic(struct page *page); > void __kunmap_atomic(void *kvaddr); > void *kmap_atomic_pfn(unsigned long pfn); > void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot); > struct page *kmap_atomic_to_page(void *ptr); > -#else > -void *__kmap_prot(struct page *page, pgprot_t prot); > -# define kmap_atomic(page) \ > - ({ pagefault_disable(); kmap(page); }) > - > -# define kmap_atomic_pfn(pfn) \ > - ({ pagefault_disable(); kmap(pfn_to_page(pfn)) }) > - > -# define __kunmap_atomic(kvaddr) \ > - do { kunmap(kmap_to_page(kvaddr)); pagefault_enable(); } while(0) > - > -# define kmap_atomic_prot(page, prot) \ > - ({ pagefault_disable(); __kmap_prot(page, prot); }) > - > -# define kmap_atomic_prot_pfn(pfn, prot) \ > - ({ pagefault_disable(); __kmap_prot(pfn_to_page(pfn), prot); }) > - > -# define kmap_atomic_to_page(kvaddr) \ > - kmap_to_page(kvaddr) > - > -#endif > > #define flush_cache_kmaps() do { } while (0) > > Index: linux-stable/arch/x86/kernel/process_32.c > =================================================================== > --- linux-stable.orig/arch/x86/kernel/process_32.c > +++ linux-stable/arch/x86/kernel/process_32.c > @@ -198,6 +198,34 @@ start_thread(struct pt_regs *regs, unsig > } > EXPORT_SYMBOL_GPL(start_thread); > > +#ifdef CONFIG_PREEMPT_RT_FULL > +static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) > +{ > + int i; > + > + /* > + * Clear @prev's kmap_atomic mappings > + */ > + for (i = 0; i < prev_p->kmap_idx; i++) { > + int idx = i + KM_TYPE_NR * smp_processor_id(); > + pte_t *ptep = kmap_pte - idx; > + > + kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx)); > + } > + /* > + * Restore @next_p's kmap_atomic mappings > + */ > + for (i = 0; i < next_p->kmap_idx; i++) { > + int idx = i + KM_TYPE_NR * smp_processor_id(); > + > + set_pte(kmap_pte - idx, next_p->kmap_pte[i]); > + } > +} > +#else > +static inline void > +switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { } > +#endif > + > > /* > * switch_to(x,y) should switch tasks from x to y. > @@ -277,40 +305,7 @@ __switch_to(struct task_struct *prev_p, > task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT)) > __switch_to_xtra(prev_p, next_p, tss); > > -#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM > - /* > - * Save @prev's kmap_atomic stack > - */ > - prev_p->kmap_idx = __this_cpu_read(__kmap_atomic_idx); > - if (unlikely(prev_p->kmap_idx)) { > - int i; > - > - for (i = 0; i < prev_p->kmap_idx; i++) { > - int idx = i + KM_TYPE_NR * smp_processor_id(); > - > - pte_t *ptep = kmap_pte - idx; > - prev_p->kmap_pte[i] = *ptep; > - kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx)); > - } > - > - __this_cpu_write(__kmap_atomic_idx, 0); > - } > - > - /* > - * Restore @next_p's kmap_atomic stack > - */ > - if (unlikely(next_p->kmap_idx)) { > - int i; > - > - __this_cpu_write(__kmap_atomic_idx, next_p->kmap_idx); > - > - for (i = 0; i < next_p->kmap_idx; i++) { > - int idx = i + KM_TYPE_NR * smp_processor_id(); > - > - set_pte(kmap_pte - idx, next_p->kmap_pte[i]); > - } > - } > -#endif > + switch_kmaps(prev_p, next_p); > > /* > * Leave lazy mode, flushing any hypercalls made here. > Index: linux-stable/arch/x86/mm/highmem_32.c > =================================================================== > --- linux-stable.orig/arch/x86/mm/highmem_32.c > +++ linux-stable/arch/x86/mm/highmem_32.c > @@ -21,17 +21,6 @@ void kunmap(struct page *page) > } > EXPORT_SYMBOL(kunmap); > > -#ifdef CONFIF_PREEMPT_RT_FULL > -void *__kmap_prot(struct page *page, pgprot_t prot) > -{ > - might_sleep(); > - if (!PageHighMem(page)) > - return page_address(page); > - return kmap_high_prot(page, prot); > -} > -#endif > - > -#ifndef CONFIG_PREEMPT_RT_FULL > /* > * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because > * no global lock is needed and because the kmap code must perform a global TLB > @@ -42,6 +31,7 @@ void *__kmap_prot(struct page *page, pgp > */ > void *kmap_atomic_prot(struct page *page, pgprot_t prot) > { > + pte_t pte = mk_pte(page, prot); > unsigned long vaddr; > int idx, type; > > @@ -55,7 +45,10 @@ void *kmap_atomic_prot(struct page *page > idx = type + KM_TYPE_NR*smp_processor_id(); > vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); > WARN_ON(!pte_none(*(kmap_pte-idx))); > - set_pte(kmap_pte-idx, mk_pte(page, prot)); > +#ifdef CONFIG_PREEMPT_RT_FULL > + current->kmap_pte[type] = pte; > +#endif > + set_pte(kmap_pte-idx, pte); > arch_flush_lazy_mmu_mode(); > > return (void *)vaddr; > @@ -126,7 +119,6 @@ struct page *kmap_atomic_to_page(void *p > return pte_page(*pte); > } > EXPORT_SYMBOL(kmap_atomic_to_page); > -#endif > > void __init set_highmem_pages_init(void) > { > Index: linux-stable/include/linux/highmem.h > =================================================================== > --- linux-stable.orig/include/linux/highmem.h > +++ linux-stable/include/linux/highmem.h > @@ -7,6 +7,7 @@ > #include <linux/mm.h> > #include <linux/uaccess.h> > #include <linux/hardirq.h> > +#include <linux/sched.h> > > #include <asm/cacheflush.h> > > @@ -59,8 +60,6 @@ static inline void *kmap(struct page *pa > return page_address(page); > } > > -#define __kmap_prot(page, prot) kmap(page) > - > static inline void kunmap(struct page *page) > { > } > @@ -87,32 +86,49 @@ static inline void __kunmap_atomic(void > > #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) > > +#ifndef CONFIG_PREEMPT_RT_FULL > DECLARE_PER_CPU(int, __kmap_atomic_idx); > +#endif > > static inline int kmap_atomic_idx_push(void) > { > +#ifndef CONFIG_PREEMPT_RT_FULL > int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; > > -#ifdef CONFIG_DEBUG_HIGHMEM > +# ifdef CONFIG_DEBUG_HIGHMEM > WARN_ON_ONCE(in_irq() && !irqs_disabled()); > BUG_ON(idx > KM_TYPE_NR); > -#endif > +# endif > return idx; > +#else > + return current->kmap_idx++; > +#endif > } > > static inline int kmap_atomic_idx(void) > { > +#ifndef CONFIG_PREEMPT_RT_FULL > return __this_cpu_read(__kmap_atomic_idx) - 1; > +#else > + return current->kmap_idx - 1; > +#endif > } > > static inline void kmap_atomic_idx_pop(void) > { > -#ifdef CONFIG_DEBUG_HIGHMEM > +#ifndef CONFIG_PREEMPT_RT_FULL > +# ifdef CONFIG_DEBUG_HIGHMEM > int idx = __this_cpu_dec_return(__kmap_atomic_idx); > > BUG_ON(idx < 0); > -#else > +# else > __this_cpu_dec(__kmap_atomic_idx); > +# endif > +#else > + current->kmap_idx--; > +# ifdef CONFIG_DEBUG_HIGHMEM > + BUG_ON(current->kmap_idx < 0); > +# endif > #endif > } > > Index: linux-stable/include/linux/sched.h > =================================================================== > --- linux-stable.orig/include/linux/sched.h > +++ linux-stable/include/linux/sched.h > @@ -1621,9 +1621,11 @@ struct task_struct { > int softirq_nestcnt; > unsigned int softirqs_raised; > #endif > -#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM > +#ifdef CONFIG_PREEMPT_RT_FULL > +# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32 > int kmap_idx; > pte_t kmap_pte[KM_TYPE_NR]; > +# endif > #endif > > #ifdef CONFIG_DEBUG_PREEMPT > Index: linux-stable/localversion-rt > =================================================================== > --- linux-stable.orig/localversion-rt > +++ linux-stable/localversion-rt > @@ -1 +1 @@ > --rt28 > +-rt29 > Index: linux-stable/mm/highmem.c > =================================================================== > --- linux-stable.orig/mm/highmem.c > +++ linux-stable/mm/highmem.c > @@ -29,10 +29,11 @@ > #include <linux/kgdb.h> > #include <asm/tlbflush.h> > > - > +#ifndef CONFIG_PREEMPT_RT_FULL > #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) > DEFINE_PER_CPU(int, __kmap_atomic_idx); > #endif > +#endif > > /* > * Virtual_count is not a pure "count". > @@ -47,8 +48,9 @@ DEFINE_PER_CPU(int, __kmap_atomic_idx); > unsigned long totalhigh_pages __read_mostly; > EXPORT_SYMBOL(totalhigh_pages); > > - > +#ifndef CONFIG_PREEMPT_RT_FULL > EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx); > +#endif > > unsigned int nr_free_highpages (void) > { > @@ -157,7 +159,7 @@ void kmap_flush_unused(void) > unlock_kmap(); > } > > -static inline unsigned long map_new_virtual(struct page *page, pgprot_t prot) > +static inline unsigned long map_new_virtual(struct page *page) > { > unsigned long vaddr; > int count; > @@ -199,7 +201,7 @@ start: > } > vaddr = PKMAP_ADDR(last_pkmap_nr); > set_pte_at(&init_mm, vaddr, > - &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, prot)); > + &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, kmap_prot)); > > pkmap_count[last_pkmap_nr] = 1; > set_page_address(page, (void *)vaddr); > @@ -215,7 +217,7 @@ start: > * > * We cannot call this from interrupts, as it may block. > */ > -void *kmap_high_prot(struct page *page, pgprot_t prot) > +void *kmap_high(struct page *page) > { > unsigned long vaddr; > > @@ -226,26 +228,13 @@ void *kmap_high_prot(struct page *page, > lock_kmap(); > vaddr = (unsigned long)page_address(page); > if (!vaddr) > - vaddr = map_new_virtual(page, prot); > + vaddr = map_new_virtual(page); > pkmap_count[PKMAP_NR(vaddr)]++; > BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2); > unlock_kmap(); > return (void*) vaddr; > } > -EXPORT_SYMBOL(kmap_high_prot); > > -/** > - * kmap_high - map a highmem page into memory > - * @page: &struct page to map > - * > - * Returns the page's virtual memory address. > - * > - * We cannot call this from interrupts, as it may block. > - */ > -void *kmap_high(struct page *page) > -{ > - return kmap_high_prot(page, kmap_prot); > -} > EXPORT_SYMBOL(kmap_high); > > #ifdef ARCH_NEEDS_KMAP_HIGH_GET > Index: linux-stable/arch/x86/mm/iomap_32.c > =================================================================== > --- linux-stable.orig/arch/x86/mm/iomap_32.c > +++ linux-stable/arch/x86/mm/iomap_32.c > @@ -56,6 +56,7 @@ EXPORT_SYMBOL_GPL(iomap_free); > > void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) > { > + pte_t pte = pfn_pte(pfn, prot); > unsigned long vaddr; > int idx, type; > > @@ -64,7 +65,10 @@ void *kmap_atomic_prot_pfn(unsigned long > type = kmap_atomic_idx_push(); > idx = type + KM_TYPE_NR * smp_processor_id(); > vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); > - set_pte(kmap_pte - idx, pfn_pte(pfn, prot)); > +#ifdef CONFIG_PREEMPT_RT_FULL > + current->kmap_pte[type] = pte; > +#endif > + set_pte(kmap_pte - idx, pte); > arch_flush_lazy_mmu_mode(); > > return (void *)vaddr; > Index: linux-stable/arch/arm/include/asm/switch_to.h > =================================================================== > --- linux-stable.orig/arch/arm/include/asm/switch_to.h > +++ linux-stable/arch/arm/include/asm/switch_to.h > @@ -3,6 +3,14 @@ > > #include <linux/thread_info.h> > > +#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM > +void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p); > +#else > +static inline void > +switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { } > +#endif > + > + > /* > * switch_to(prev, next) should switch from task `prev' to `next' > * `prev' will never be the same as `next'. schedule() itself > @@ -12,6 +20,7 @@ extern struct task_struct *__switch_to(s > > #define switch_to(prev,next,last) \ > do { \ > + switch_kmaps(prev, next); \ > last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \ > } while (0) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
