From 8174c430e445a93016ef18f717fe570214fa38bf Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 25 Jul 2008 19:45:24 -0700 Subject: x86: lockless get_user_pages_fast() Implement get_user_pages_fast without locking in the fastpath on x86. Do an optimistic lockless pagetable walk, without taking mmap_sem or any page table locks or even mmap_sem. Page table existence is guaranteed by turning interrupts off (combined with the fact that we're always looking up the current mm, means we can do the lockless page table walk within the constraints of the TLB shootdown design). Basically we can do this lockless pagetable walk in a similar manner to the way the CPU's pagetable walker does not have to take any locks to find present ptes. This patch (combined with the subsequent ones to convert direct IO to use it) was found to give about 10% performance improvement on a 2 socket 8 core Intel Xeon system running an OLTP workload on DB2 v9.5 "To test the effects of the patch, an OLTP workload was run on an IBM x3850 M2 server with 2 processors (quad-core Intel Xeon processors at 2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing runs with and without the patch resulted in an overall performance benefit of ~9.8%. Correspondingly, oprofiles showed that samples from __up_read and __down_read routines that is seen during thread contention for system resources was reduced from 2.8% down to .05%. Monitoring the /proc/vmstat output from the patched run showed that the counter for fast_gup contained a very high number while the fast_gup_slow value was zero." (fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a counter we had for the number of times the slowpath was invoked). The main reason for the improvement is that DB2 has multiple threads each issuing direct-IO. Direct-IO uses get_user_pages, and thus the threads contend the mmap_sem cacheline, and can also contend on page table locks. I would anticipate larger performance gains on larger systems, however I think DB2 uses an adaptive mix of threads and processes, so it could be that thread contention remains pretty constant as machine size increases. In which case, we stuck with "only" a 10% gain. The downside of using get_user_pages_fast is that if there is not a pte with the correct permissions for the access, we end up falling back to get_user_pages and so the get_user_pages_fast is a bit of extra work. However this should not be the common case in most performance critical code. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: Kconfig fix] [akpm@linux-foundation.org: Makefile fix/cleanup] [akpm@linux-foundation.org: warning fix] Signed-off-by: Nick Piggin Cc: Dave Kleikamp Cc: Andy Whitcroft Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andi Kleen Cc: Dave Kleikamp Cc: Badari Pulavarty Cc: Zach Brown Cc: Jens Axboe Reviewed-by: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/Makefile | 1 + arch/x86/mm/gup.c | 258 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 259 insertions(+) create mode 100644 arch/x86/mm/gup.c (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 1fbb844c3d7a..2977ea37791f 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -1,6 +1,7 @@ obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \ pat.o pgtable.o +obj-$(CONFIG_HAVE_GET_USER_PAGES_FAST) += gup.o obj-$(CONFIG_X86_32) += pgtable_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c new file mode 100644 index 000000000000..6f733121f32e --- /dev/null +++ b/arch/x86/mm/gup.c @@ -0,0 +1,258 @@ +/* + * Lockless get_user_pages_fast for x86 + * + * Copyright (C) 2008 Nick Piggin + * Copyright (C) 2008 Novell Inc. + */ +#include +#include +#include +#include + +#include + +static inline pte_t gup_get_pte(pte_t *ptep) +{ +#ifndef CONFIG_X86_PAE + return *ptep; +#else + /* + * With get_user_pages_fast, we walk down the pagetables without taking + * any locks. For this we would like to load the pointers atoimcally, + * but that is not possible (without expensive cmpxchg8b) on PAE. What + * we do have is the guarantee that a pte will only either go from not + * present to present, or present to not present or both -- it will not + * switch to a completely different present page without a TLB flush in + * between; something that we are blocking by holding interrupts off. + * + * Setting ptes from not present to present goes: + * ptep->pte_high = h; + * smp_wmb(); + * ptep->pte_low = l; + * + * And present to not present goes: + * ptep->pte_low = 0; + * smp_wmb(); + * ptep->pte_high = 0; + * + * We must ensure here that the load of pte_low sees l iff pte_high + * sees h. We load pte_high *after* loading pte_low, which ensures we + * don't see an older value of pte_high. *Then* we recheck pte_low, + * which ensures that we haven't picked up a changed pte high. We might + * have got rubbish values from pte_low and pte_high, but we are + * guaranteed that pte_low will not have the present bit set *unless* + * it is 'l'. And get_user_pages_fast only operates on present ptes, so + * we're safe. + * + * gup_get_pte should not be used or copied outside gup.c without being + * very careful -- it does not atomically load the pte or anything that + * is likely to be useful for you. + */ + pte_t pte; + +retry: + pte.pte_low = ptep->pte_low; + smp_rmb(); + pte.pte_high = ptep->pte_high; + smp_rmb(); + if (unlikely(pte.pte_low != ptep->pte_low)) + goto retry; + + return pte; +#endif +} + +/* + * The performance critical leaf functions are made noinline otherwise gcc + * inlines everything into a single function which results in too much + * register pressure. + */ +static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, + unsigned long end, int write, struct page **pages, int *nr) +{ + unsigned long mask; + pte_t *ptep; + + mask = _PAGE_PRESENT|_PAGE_USER; + if (write) + mask |= _PAGE_RW; + + ptep = pte_offset_map(&pmd, addr); + do { + pte_t pte = gup_get_pte(ptep); + struct page *page; + + if ((pte_val(pte) & (mask | _PAGE_SPECIAL)) != mask) { + pte_unmap(ptep); + return 0; + } + VM_BUG_ON(!pfn_valid(pte_pfn(pte))); + page = pte_page(pte); + get_page(page); + pages[*nr] = page; + (*nr)++; + + } while (ptep++, addr += PAGE_SIZE, addr != end); + pte_unmap(ptep - 1); + + return 1; +} + +static inline void get_head_page_multiple(struct page *page, int nr) +{ + VM_BUG_ON(page != compound_head(page)); + VM_BUG_ON(page_count(page) == 0); + atomic_add(nr, &page->_count); +} + +static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, + unsigned long end, int write, struct page **pages, int *nr) +{ + unsigned long mask; + pte_t pte = *(pte_t *)&pmd; + struct page *head, *page; + int refs; + + mask = _PAGE_PRESENT|_PAGE_USER; + if (write) + mask |= _PAGE_RW; + if ((pte_val(pte) & mask) != mask) + return 0; + /* hugepages are never "special" */ + VM_BUG_ON(pte_val(pte) & _PAGE_SPECIAL); + VM_BUG_ON(!pfn_valid(pte_pfn(pte))); + + refs = 0; + head = pte_page(pte); + page = head + ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); + do { + VM_BUG_ON(compound_head(page) != head); + pages[*nr] = page; + (*nr)++; + page++; + refs++; + } while (addr += PAGE_SIZE, addr != end); + get_head_page_multiple(head, refs); + + return 1; +} + +static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, + int write, struct page **pages, int *nr) +{ + unsigned long next; + pmd_t *pmdp; + + pmdp = pmd_offset(&pud, addr); + do { + pmd_t pmd = *pmdp; + + next = pmd_addr_end(addr, end); + if (pmd_none(pmd)) + return 0; + if (unlikely(pmd_large(pmd))) { + if (!gup_huge_pmd(pmd, addr, next, write, pages, nr)) + return 0; + } else { + if (!gup_pte_range(pmd, addr, next, write, pages, nr)) + return 0; + } + } while (pmdp++, addr = next, addr != end); + + return 1; +} + +static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, + int write, struct page **pages, int *nr) +{ + unsigned long next; + pud_t *pudp; + + pudp = pud_offset(&pgd, addr); + do { + pud_t pud = *pudp; + + next = pud_addr_end(addr, end); + if (pud_none(pud)) + return 0; + if (!gup_pmd_range(pud, addr, next, write, pages, nr)) + return 0; + } while (pudp++, addr = next, addr != end); + + return 1; +} + +int get_user_pages_fast(unsigned long start, int nr_pages, int write, + struct page **pages) +{ + struct mm_struct *mm = current->mm; + unsigned long end = start + (nr_pages << PAGE_SHIFT); + unsigned long addr = start; + unsigned long next; + pgd_t *pgdp; + int nr = 0; + + if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ, + start, nr_pages*PAGE_SIZE))) + goto slow_irqon; + + /* + * XXX: batch / limit 'nr', to avoid large irq off latency + * needs some instrumenting to determine the common sizes used by + * important workloads (eg. DB2), and whether limiting the batch size + * will decrease performance. + * + * It seems like we're in the clear for the moment. Direct-IO is + * the main guy that batches up lots of get_user_pages, and even + * they are limited to 64-at-a-time which is not so many. + */ + /* + * This doesn't prevent pagetable teardown, but does prevent + * the pagetables and pages from being freed on x86. + * + * So long as we atomically load page table pointers versus teardown + * (which we do on x86, with the above PAE exception), we can follow the + * address down to the the page and take a ref on it. + */ + local_irq_disable(); + pgdp = pgd_offset(mm, addr); + do { + pgd_t pgd = *pgdp; + + next = pgd_addr_end(addr, end); + if (pgd_none(pgd)) + goto slow; + if (!gup_pud_range(pgd, addr, next, write, pages, &nr)) + goto slow; + } while (pgdp++, addr = next, addr != end); + local_irq_enable(); + + VM_BUG_ON(nr != (end - start) >> PAGE_SHIFT); + return nr; + + { + int ret; + +slow: + local_irq_enable(); +slow_irqon: + /* Try to get the remaining pages with get_user_pages */ + start += nr << PAGE_SHIFT; + pages += nr; + + down_read(&mm->mmap_sem); + ret = get_user_pages(current, mm, start, + (end - start) >> PAGE_SHIFT, write, 0, pages, NULL); + up_read(&mm->mmap_sem); + + /* Have to be a bit careful with return values */ + if (nr > 0) { + if (ret < 0) + ret = nr; + else + ret += nr; + } + + return ret; + } +} -- cgit v1.2.2 From 652ea695364142b2464744746beac206d050ef19 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 25 Jul 2008 19:45:27 -0700 Subject: x86: support 1GB hugepages with get_user_pages_lockless() Signed-off-by: Nick Piggin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/gup.c | 43 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 6f733121f32e..3085f25b4355 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -124,7 +124,7 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, refs = 0; head = pte_page(pte); - page = head + ((addr & ~HPAGE_MASK) >> PAGE_SHIFT); + page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); do { VM_BUG_ON(compound_head(page) != head); pages[*nr] = page; @@ -162,6 +162,38 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, return 1; } +static noinline int gup_huge_pud(pud_t pud, unsigned long addr, + unsigned long end, int write, struct page **pages, int *nr) +{ + unsigned long mask; + pte_t pte = *(pte_t *)&pud; + struct page *head, *page; + int refs; + + mask = _PAGE_PRESENT|_PAGE_USER; + if (write) + mask |= _PAGE_RW; + if ((pte_val(pte) & mask) != mask) + return 0; + /* hugepages are never "special" */ + VM_BUG_ON(pte_val(pte) & _PAGE_SPECIAL); + VM_BUG_ON(!pfn_valid(pte_pfn(pte))); + + refs = 0; + head = pte_page(pte); + page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT); + do { + VM_BUG_ON(compound_head(page) != head); + pages[*nr] = page; + (*nr)++; + page++; + refs++; + } while (addr += PAGE_SIZE, addr != end); + get_head_page_multiple(head, refs); + + return 1; +} + static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { @@ -175,8 +207,13 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end, next = pud_addr_end(addr, end); if (pud_none(pud)) return 0; - if (!gup_pmd_range(pud, addr, next, write, pages, nr)) - return 0; + if (unlikely(pud_large(pud))) { + if (!gup_huge_pud(pud, addr, next, write, pages, nr)) + return 0; + } else { + if (!gup_pmd_range(pud, addr, next, write, pages, nr)) + return 0; + } } while (pudp++, addr = next, addr != end); return 1; -- cgit v1.2.2 From 8dad322f5449010c14990dd6934878f576b2ee60 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 25 Jul 2008 19:46:11 -0700 Subject: x86: use generic show_mem() Remove arch-specific show_mem() in favor of the generic version. This also removes the following redundant information display: - pages in swapcache, printed by show_swap_cache_info() - dirty pages, writeback pages, mapped pages, slab pages, pagetable pages, printed by show_free_areas() where show_mem() calls show_free_areas(), which calls show_swap_cache_info(). Signed-off-by: Johannes Weiner Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/init_64.c | 37 ------------------------------------- arch/x86/mm/pgtable_32.c | 47 ----------------------------------------------- 2 files changed, 84 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index ec37121f6709..129618ca0ea2 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -86,43 +86,6 @@ early_param("gbpages", parse_direct_gbpages_on); * around without checking the pgd every time. */ -void show_mem(void) -{ - long i, total = 0, reserved = 0; - long shared = 0, cached = 0; - struct page *page; - pg_data_t *pgdat; - - printk(KERN_INFO "Mem-info:\n"); - show_free_areas(); - for_each_online_pgdat(pgdat) { - for (i = 0; i < pgdat->node_spanned_pages; ++i) { - /* - * This loop can take a while with 256 GB and - * 4k pages so defer the NMI watchdog: - */ - if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) - touch_nmi_watchdog(); - - if (!pfn_valid(pgdat->node_start_pfn + i)) - continue; - - page = pfn_to_page(pgdat->node_start_pfn + i); - total++; - if (PageReserved(page)) - reserved++; - else if (PageSwapCache(page)) - cached++; - else if (page_count(page)) - shared += page_count(page) - 1; - } - } - printk(KERN_INFO "%lu pages of RAM\n", total); - printk(KERN_INFO "%lu reserved pages\n", reserved); - printk(KERN_INFO "%lu pages shared\n", shared); - printk(KERN_INFO "%lu pages swap cached\n", cached); -} - int after_bootmem; static __init void *spp_getpage(void) diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index b4becbf8c570..cab0abbd1ebe 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -20,53 +20,6 @@ #include #include -void show_mem(void) -{ - int total = 0, reserved = 0; - int shared = 0, cached = 0; - int highmem = 0; - struct page *page; - pg_data_t *pgdat; - unsigned long i; - unsigned long flags; - - printk(KERN_INFO "Mem-info:\n"); - show_free_areas(); - for_each_online_pgdat(pgdat) { - pgdat_resize_lock(pgdat, &flags); - for (i = 0; i < pgdat->node_spanned_pages; ++i) { - if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) - touch_nmi_watchdog(); - page = pgdat_page_nr(pgdat, i); - total++; - if (PageHighMem(page)) - highmem++; - if (PageReserved(page)) - reserved++; - else if (PageSwapCache(page)) - cached++; - else if (page_count(page)) - shared += page_count(page) - 1; - } - pgdat_resize_unlock(pgdat, &flags); - } - printk(KERN_INFO "%d pages of RAM\n", total); - printk(KERN_INFO "%d pages of HIGHMEM\n", highmem); - printk(KERN_INFO "%d reserved pages\n", reserved); - printk(KERN_INFO "%d pages shared\n", shared); - printk(KERN_INFO "%d pages swap cached\n", cached); - - printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY)); - printk(KERN_INFO "%lu pages writeback\n", - global_page_state(NR_WRITEBACK)); - printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED)); - printk(KERN_INFO "%lu pages slab\n", - global_page_state(NR_SLAB_RECLAIMABLE) + - global_page_state(NR_SLAB_UNRECLAIMABLE)); - printk(KERN_INFO "%lu pages pagetables\n", - global_page_state(NR_PAGETABLE)); -} - /* * Associate a virtual page frame with a given physical page frame * and protection flags for that frame. -- cgit v1.2.2 From 9b79022ca909b66e2cd0cfd9248f832fc165f77f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 28 Jul 2008 17:54:21 -0700 Subject: Fix 'get_user_pages_fast()' with non-page-aligned start address Alexey Dobriyan reported trouble with LTP with the new fast-gup code, and Johannes Weiner debugged it to non-page-aligned addresses, where the new get_user_pages_fast() code would do all the wrong things, including just traversing past the end of the requested area due to 'addr' never matching 'end' exactly. This is not a pretty fix, and we may actually want to move the alignment into generic code, leaving just the core code per-arch, but Alexey verified that the vmsplice01 LTP test doesn't crash with this. Reported-and-tested-by: Alexey Dobriyan Debugged-by: Johannes Weiner Cc: Nick Piggin Cc: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/gup.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 3085f25b4355..007bb06c7504 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -223,14 +223,17 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) { struct mm_struct *mm = current->mm; - unsigned long end = start + (nr_pages << PAGE_SHIFT); - unsigned long addr = start; + unsigned long addr, len, end; unsigned long next; pgd_t *pgdp; int nr = 0; + start &= PAGE_MASK; + addr = start; + len = (unsigned long) nr_pages << PAGE_SHIFT; + end = start + len; if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ, - start, nr_pages*PAGE_SIZE))) + start, len))) goto slow_irqon; /* -- cgit v1.2.2 From cf3e50501259f9a7cb108a69c3e1b912135628f6 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 8 Aug 2008 13:46:07 -0700 Subject: x86: work around gcc 3.4.x bug Simon Horman reported that gcc-3.4.x crashes when compiling pgd_prepopulate_pmd() when PREALLOCATED_PMDS == 0 and CONFIG_DEBUG_INFO is enabled. Adding an extra check for PREALLOCATED_PMDS == 0 [which is compiled out by gcc] seems to avoid the problem. Reported-by: Simon Horman Signed-off-by: Jeremy Fitzhardinge Acked-by: Simon Horman Signed-off-by: Ingo Molnar --- arch/x86/mm/pgtable.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 557b2abceef8..d50302774fe2 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -207,6 +207,9 @@ static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[]) unsigned long addr; int i; + if (PREALLOCATED_PMDS == 0) /* Work around gcc-3.4.x bug */ + return; + pud = pud_offset(pgd, 0); for (addr = i = 0; i < PREALLOCATED_PMDS; -- cgit v1.2.2 From 912985dce45ef18fcdd9f5439fef054e0e22302a Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 12 Aug 2008 17:52:52 -0500 Subject: mm: Make generic weak get_user_pages_fast and EXPORT_GPL it Out of line get_user_pages_fast fallback implementation, make it a weak symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST. Export the symbol to modules so lguest can use it. Signed-off-by: Nick Piggin Signed-off-by: Rusty Russell --- arch/x86/mm/Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 2977ea37791f..dfb932dcf136 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -1,7 +1,6 @@ obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \ - pat.o pgtable.o + pat.o pgtable.o gup.o -obj-$(CONFIG_HAVE_GET_USER_PAGES_FAST) += gup.o obj-$(CONFIG_X86_32) += pgtable_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o -- cgit v1.2.2 From 875e40b97571e1f06d1184ad6cbb2acf9cb31a23 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 30 Jul 2008 12:26:26 -0700 Subject: x86: use WARN() in arch/x86/mm/pageattr.c Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. Signed-off-by: Arjan van de Ven Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Cc: akpm@linux-foundation.org Cc: arjan@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr-test.c | 3 +-- arch/x86/mm/pageattr.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c index 0dcd42eb94e6..d4aa503caaa2 100644 --- a/arch/x86/mm/pageattr-test.c +++ b/arch/x86/mm/pageattr-test.c @@ -221,8 +221,7 @@ static int pageattr_test(void) failed += print_split(&sc); if (failed) { - printk(KERN_ERR "NOT PASSED. Please report.\n"); - WARN_ON(1); + WARN(1, KERN_ERR "NOT PASSED. Please report.\n"); return -EINVAL; } else { if (print) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 65c6e46bf059..ba24537d69dd 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -592,10 +592,9 @@ repeat: if (!pte_val(old_pte)) { if (!primary) return 0; - printk(KERN_WARNING "CPA: called for zero pte. " + WARN(1, KERN_WARNING "CPA: called for zero pte. " "vaddr = %lx cpa->vaddr = %lx\n", address, cpa->vaddr); - WARN_ON(1); return -EINVAL; } -- cgit v1.2.2 From 858f774733b72609acb28104475f131abb912c08 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 14 Aug 2008 02:16:29 -0700 Subject: x86: don't call e820_regiter_active_regions if out of range on node so we don't get warning on 32bit system with 64g RAM or more Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- arch/x86/mm/srat_32.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/srat_32.c b/arch/x86/mm/srat_32.c index 1eb2973a301c..16ae70fc57e7 100644 --- a/arch/x86/mm/srat_32.c +++ b/arch/x86/mm/srat_32.c @@ -178,7 +178,7 @@ void acpi_numa_arch_fixup(void) * start of the node, and that the current "end" address is after * the previous one. */ -static __init void node_read_chunk(int nid, struct node_memory_chunk_s *memory_chunk) +static __init int node_read_chunk(int nid, struct node_memory_chunk_s *memory_chunk) { /* * Only add present memory as told by the e820. @@ -189,10 +189,10 @@ static __init void node_read_chunk(int nid, struct node_memory_chunk_s *memory_c if (memory_chunk->start_pfn >= max_pfn) { printk(KERN_INFO "Ignoring SRAT pfns: %08lx - %08lx\n", memory_chunk->start_pfn, memory_chunk->end_pfn); - return; + return -1; } if (memory_chunk->nid != nid) - return; + return -1; if (!node_has_online_mem(nid)) node_start_pfn[nid] = memory_chunk->start_pfn; @@ -202,6 +202,8 @@ static __init void node_read_chunk(int nid, struct node_memory_chunk_s *memory_c if (node_end_pfn[nid] < memory_chunk->end_pfn) node_end_pfn[nid] = memory_chunk->end_pfn; + + return 0; } int __init get_memcfg_from_srat(void) @@ -259,7 +261,9 @@ int __init get_memcfg_from_srat(void) printk(KERN_DEBUG "chunk %d nid %d start_pfn %08lx end_pfn %08lx\n", j, chunk->nid, chunk->start_pfn, chunk->end_pfn); - node_read_chunk(chunk->nid, chunk); + if (node_read_chunk(chunk->nid, chunk)) + continue; + e820_register_active_regions(chunk->nid, chunk->start_pfn, min(chunk->end_pfn, max_pfn)); } -- cgit v1.2.2 From a06de63000b95e1ed1c6373a72376876c952608e Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Fri, 15 Aug 2008 13:58:32 +0100 Subject: x86: fix /proc/meminfo DirectMap Do we actually want these DirectMap lines in the x86 /proc/meminfo? I can see they're interesting to CPA developers and TLB optimizers, but they don't fit its usual "where has all my memory gone?" usage. If they are to stay, here are some fixes. 1. On x86_32 without PAE, they're not 2M but 4M pages: no need to mess with the internal enum, but show the right name to users. 2. Many machines can never show anything but 0 for DirectMap1G, so suppress that line unless direct_gbpages are really enabled. 3. The unit in /proc/meminfo is kB not number of pages: HugePages messed that up, but they're an example to regret not to follow. 4. Once we use kB, it's easy to see that 1GB has gone missing (which explains why CONFIG_CPA_DEBUG=y soon wraps DirectMap2M negative): because head_64.S's level2_ident_pgt entries were not counted. My fix is not ideal, but works for more and for less than 1G, and avoids interfering with early bootup pagetable contortions. Signed-off-by: Hugh Dickins Cc: Andi Kleen Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 6 +++++- arch/x86/mm/pageattr.c | 18 ++++++++++++------ 2 files changed, 17 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 129618ca0ea2..b3e6c3075acc 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -60,7 +60,7 @@ static unsigned long dma_reserve __initdata; DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); -int direct_gbpages __meminitdata +int direct_gbpages #ifdef CONFIG_DIRECT_GBPAGES = 1 #endif @@ -314,6 +314,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, { unsigned long pages = 0; unsigned long last_map_addr = end; + unsigned long start = address; int i = pmd_index(address); @@ -334,6 +335,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (!pmd_large(*pmd)) last_map_addr = phys_pte_update(pmd, address, end); + /* Count entries we're using from level2_ident_pgt */ + if (start == 0) + pages++; continue; } diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index ba24537d69dd..f5f5154ea11e 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -55,13 +55,19 @@ static void split_page_count(int level) int arch_report_meminfo(char *page) { - int n = sprintf(page, "DirectMap4k: %8lu\n" - "DirectMap2M: %8lu\n", - direct_pages_count[PG_LEVEL_4K], - direct_pages_count[PG_LEVEL_2M]); + int n = sprintf(page, "DirectMap4k: %8lu kB\n", + direct_pages_count[PG_LEVEL_4K] << 2); +#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) + n += sprintf(page + n, "DirectMap2M: %8lu kB\n", + direct_pages_count[PG_LEVEL_2M] << 11); +#else + n += sprintf(page + n, "DirectMap4M: %8lu kB\n", + direct_pages_count[PG_LEVEL_2M] << 12); +#endif #ifdef CONFIG_X86_64 - n += sprintf(page + n, "DirectMap1G: %8lu\n", - direct_pages_count[PG_LEVEL_1G]); + if (direct_gbpages) + n += sprintf(page + n, "DirectMap1G: %8lu kB\n", + direct_pages_count[PG_LEVEL_1G] << 20); #endif return n; } -- cgit v1.2.2 From e213e87785559eaf3107897226817aea9291b06f Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 15 Aug 2008 18:12:47 +0200 Subject: x86: Fix ioremap off by one BUG Jean Delvare's machine triggered this BUG acpi_os_map_memory phys ffff0000 size 65535 ------------[ cut here ]------------ kernel BUG at arch/x86/mm/pat.c:233! with ACPI in the backtrace. Adding some debugging output showed that ACPI calls acpi_os_map_memory phys ffff0000 size 65535 And ioremap/PAT does this check in 32bit, so addr+size wraps and the BUG in reserve_memtype() triggers incorrectly. BUG_ON(start >= end); /* end is exclusive */ But reserve_memtype already uses u64: int reserve_memtype(u64 start, u64 end, so the 32bit truncation must happen in the caller. Presumably in ioremap when it passes this information to reserve_memtype(). This patch does this computation in 64bit. http://bugzilla.kernel.org/show_bug.cgi?id=11346 Signed-off-by: Andi Kleen --- arch/x86/mm/ioremap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 016f335bbeea..6ba6f889c79d 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -170,7 +170,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, phys_addr &= PAGE_MASK; size = PAGE_ALIGN(last_addr+1) - phys_addr; - retval = reserve_memtype(phys_addr, phys_addr + size, + retval = reserve_memtype(phys_addr, (u64)phys_addr + size, prot_val, &new_prot_val); if (retval) { pr_debug("Warning: reserve_memtype returned %d\n", retval); -- cgit v1.2.2 From 8d6ea9674cb12b90c800dc572214bf06f6ce8340 Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Fri, 15 Aug 2008 18:32:24 +0200 Subject: x86: fix section mismatch warning - spp_getpage() WARNING: vmlinux.o(.text+0x17a3e): Section mismatch in reference from the function set_pte_vaddr_pud() to the function .init.text:spp_getpage() The function set_pte_vaddr_pud() references the function __init spp_getpage(). This is often because set_pte_vaddr_pud lacks a __init annotation or the annotation of spp_getpage is wrong. spp_getpage is called from __init (__init_extra_mapping) and non __init (set_pte_vaddr_pud) functions, so it can't be __init. Unfortunately it calls alloc_bootmem_pages which is __init, but does it only when bootmem allocator is available (after_bootmem == 0). So annotate it accordingly. Signed-off-by: Marcin Slusarz Signed-off-by: Ingo Molnar Cc: H. Peter Anvin --- arch/x86/mm/init_64.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b3e6c3075acc..a87ea0e4b3dc 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -88,7 +88,11 @@ early_param("gbpages", parse_direct_gbpages_on); int after_bootmem; -static __init void *spp_getpage(void) +/* + * NOTE: This function is marked __ref because it calls __init function + * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. + */ +static __ref void *spp_getpage(void) { void *ptr; -- cgit v1.2.2