litmus-rt.git - The LITMUS^RT kernel.

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author	Wu Fengguang <fengguang.wu@intel.com>	2010-03-01 08:55:51 -0500
committer	H. Peter Anvin <hpa@zytor.com>	2010-03-01 13:18:32 -0500
commit	37b99dd5372cff42f83210c280f314f10f99138e (patch)
tree	b5fd741c214f308373232c26e82be9c7628c285c /lib/debugobjects.c
parent	dad52fc01161afcb8798c609e009aed4d104927f (diff)

resource: Fix generic page_is_ram() for partial RAM pages

The System RAM walk shall skip partial RAM pages and avoid calling func() on them. So that page_is_ram() return 0 for a partial RAM page. In particular, it shall not call func() with len=0. This fixes a boot time bug reported by Sachin and root caused by Thomas: > >>> WARNING: at arch/x86/mm/ioremap.c:111 __ioremap_caller+0x169/0x2f1() > >>> Hardware name: BladeCenter LS21 -[79716AA]- > >>> Modules linked in: > >>> Pid: 0, comm: swapper Not tainted 2.6.33-git6-autotest #1 > >>> Call Trace: > >>> [<ffffffff81047cff>] ? __ioremap_caller+0x169/0x2f1 > >>> [<ffffffff81063b7d>] warn_slowpath_common+0x77/0xa4 > >>> [<ffffffff81063bb9>] warn_slowpath_null+0xf/0x11 > >>> [<ffffffff81047cff>] __ioremap_caller+0x169/0x2f1 > >>> [<ffffffff813747a3>] ? acpi_os_map_memory+0x12/0x1b > >>> [<ffffffff81047f10>] ioremap_nocache+0x12/0x14 > >>> [<ffffffff813747a3>] acpi_os_map_memory+0x12/0x1b > >>> [<ffffffff81282fa0>] acpi_tb_verify_table+0x29/0x5b > >>> [<ffffffff812827f0>] acpi_load_tables+0x39/0x15a > >>> [<ffffffff8191c8f8>] acpi_early_init+0x60/0xf5 > >>> [<ffffffff818f2cad>] start_kernel+0x397/0x3a7 > >>> [<ffffffff818f2295>] x86_64_start_reservations+0xa5/0xa9 > >>> [<ffffffff818f237a>] x86_64_start_kernel+0xe1/0xe8 > >>> ---[ end trace 4eaa2a86a8e2da22 ]--- > >>> ioremap reserve_memtype failed -22 The return code is -EINVAL, so it failed in the is_ram check, which is not too surprising > BIOS-provided physical RAM map: > BIOS-e820: 0000000000000000 - 000000000009c000 (usable) > BIOS-e820: 000000000009c000 - 00000000000a0000 (reserved) > BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) > BIOS-e820: 0000000000100000 - 00000000cffa3900 (usable) > BIOS-e820: 00000000cffa3900 - 00000000cffa7400 (ACPI data) The ACPI data is not starting on a page boundary and neither does the usable RAM area end on a page boundary. Very useful ! > ACPI: DSDT 00000000cffa3900 036CE (v01 IBM SERLEWIS 00001000 INTL 20060912) ACPI is trying to map DSDT at cffa3900, which results in a check vs. cffa3000 which is the relevant page boundary. The generic is_ram check correctly identifies that as RAM because it's in the usable resource area. The old e820 based is_ram check does not take overlapping resource areas into account. That's why it works. CC: Sachin Sant <sachinp@in.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> LKML-Reference: <20100301135551.GA9998@localhost> Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Diffstat (limited to 'lib/debugobjects.c')

0 files changed, 0 insertions, 0 deletions

/* * kernel/lockdep_proc.c * * Runtime locking correctness validator * * Started by Ingo Molnar: * * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> * * Code for /proc/lockdep and /proc/lockdep_stats: * */ #include <linux/export.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/kallsyms.h> #include <linux/debug_locks.h> #include <linux/vmalloc.h> #include <linux/sort.h> #include <asm/uaccess.h> #include <asm/div64.h> #include "lockdep_internals.h" static void *l_next(struct seq_file *m, void *v, loff_t *pos) { return seq_list_next(v, &all_lock_classes, pos); } static void *l_start(struct seq_file *m, loff_t *pos) { return seq_list_start_head(&all_lock_classes, *pos); } static void l_stop(struct seq_file *m, void *v) { } static void print_name(struct seq_file *m, struct lock_class *class) { char str[KSYM_NAME_LEN]; const char *name = class->name; if (!name) { name = __get_key_name(class->key, str); seq_printf(m, "%s", name); } else{ seq_printf(m, "%s", name); if (class->name_version > 1) seq_printf(m, "#%d", class->name_version); if (class->subclass) seq_printf(m, "/%d", class->subclass); } } static int l_show(struct seq_file *m, void *v) { struct lock_class *class = list_entry(v, struct lock_class, lock_entry); struct lock_list *entry; char usage[LOCK_USAGE_CHARS]; if (v == &all_lock_classes) { seq_printf(m, "all lock classes:\n"); return 0; } seq_printf(m, "%p", class->key); #ifdef CONFIG_DEBUG_LOCKDEP seq_printf(m, " OPS:%8ld", class->ops); #endif #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class)); seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); #endif get_usage_chars(class, usage); seq_printf(m, " %s", usage); seq_printf(m, ": "); print_name(m, class); seq_puts(m, "\n"); list_for_each_entry(entry, &class->locks_after, entry) { if (entry->distance == 1) { seq_printf(m, " -> [%p] ", entry->class->key); print_name(m, entry->class); seq_puts(m, "\n"); } } seq_puts(m, "\n"); return 0; } static const struct seq_operations lockdep_ops = { .start = l_start, .next = l_next, .stop = l_stop, .show = l_show, }; static int lockdep_open(struct inode *inode, struct file *file) { return seq_open(file, &lockdep_ops); } static const struct file_operations proc_lockdep_operations = { .open = lockdep_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #ifdef CONFIG_PROVE_LOCKING static void *lc_start(struct seq_file *m, loff_t *pos) { if (*pos == 0) return SEQ_START_TOKEN; if (*pos - 1 < nr_lock_chains) return lock_chains + (*pos - 1); return NULL; } static void *lc_next(struct seq_file *m, void *v, loff_t *pos) { (*pos)++; return lc_start(m, pos); } static void lc_stop(struct seq_file *m, void *v) { } static int lc_show(struct seq_file *m, void *v) { struct lock_chain *chain = v; struct lock_class *class; int i; if (v == SEQ_START_TOKEN) { seq_printf(m, "all lock chains:\n"); return 0; } seq_printf(m, "irq_context: %d\n", chain->irq_context); for (i = 0; i < chain->depth; i++) { class = lock_chain_get_class(chain, i); if (!class->key) continue; seq_printf(m, "[%p] ", class->key); print_name(m, class); seq_puts(m, "\n"); } seq_puts(m, "\n"); return 0; } static const struct seq_operations lockdep_chains_ops = { .start = lc_start, .next = lc_next, .stop = lc_stop, .show = lc_show, }; static int lockdep_chains_open(struct inode *inode, struct file *file) { return seq_open(file, &lockdep_chains_ops); } static const struct file_operations proc_lockdep_chains_operations = { .open = lockdep_chains_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #endif /* CONFIG_PROVE_LOCKING */ static void lockdep_stats_debug_show(struct seq_file *m) { #ifdef CONFIG_DEBUG_LOCKDEP unsigned long long hi1 = debug_atomic_read(hardirqs_on_events), hi2 = debug_atomic_read(hardirqs_off_events), hr1 = debug_atomic_read(redundant_hardirqs_on), hr2 = debug_atomic_read(redundant_hardirqs_off), si1 = debug_atomic_read(softirqs_on_events), si2 = debug_atomic_read(softirqs_off_events), sr1 = debug_atomic_read(redundant_softirqs_on), sr2 = debug_atomic_read(redundant_softirqs_off); seq_printf(m, " chain lookup misses: %11llu\n", debug_atomic_read(chain_lookup_misses)); seq_printf(m, " chain lookup hits: %11llu\n", debug_atomic_read(chain_lookup_hits)); seq_printf(m, " cyclic checks: %11llu\n", debug_atomic_read(nr_cyclic_checks)); seq_printf(m, " find-mask forwards checks: %11llu\n", debug_atomic_read(nr_find_usage_forwards_checks)); seq_printf(m, " find-mask backwards checks: %11llu\n", debug_atomic_read(nr_find_usage_backwards_checks)); seq_printf(m, " hardirq on events: %11llu\n", hi1); seq_printf(m, " hardirq off events: %11llu\n", hi2); seq_printf(m, " redundant hardirq ons: %11llu\n", hr1); seq_printf(m, " redundant hardirq offs: %11llu\n", hr2); seq_printf(m, " softirq on events: %11llu\n", si1); seq_printf(m, " softirq off events: %11llu\n", si2); seq_printf(m, " redundant softirq ons: %11llu\n", sr1); seq_printf(m, " redundant softirq offs: %11llu\n", sr2); #endif } static int lockdep_stats_show(struct seq_file *m, void *v) { struct lock_class *class; unsigned long nr_unused = 0, nr_uncategorized = 0, nr_irq_safe = 0, nr_irq_unsafe = 0, nr_softirq_safe = 0, nr_softirq_unsafe = 0, nr_hardirq_safe = 0, nr_hardirq_unsafe = 0, nr_irq_read_safe = 0, nr_irq_read_unsafe = 0, nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0, nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, sum_forward_deps = 0; list_for_each_entry(class, &all_lock_classes, lock_entry) { if (class->usage_mask == 0) nr_unused++; if (class->usage_mask == LOCKF_USED) nr_uncategorized++; if (class->usage_mask & LOCKF_USED_IN_IRQ) nr_irq_safe++; if (class->usage_mask & LOCKF_ENABLED_IRQ) nr_irq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ) nr_softirq_safe++; if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ) nr_softirq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_HARDIRQ) nr_hardirq_safe++; if (class->usage_mask & LOCKF_ENABLED_HARDIRQ) nr_hardirq_unsafe++; if (class->usage_mask & LOCKF_USED_IN_IRQ_READ) nr_irq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_IRQ_READ) nr_irq_read_unsafe++; if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) nr_softirq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ) nr_softirq_read_unsafe++; if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) nr_hardirq_read_safe++; if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) nr_hardirq_read_unsafe++; #ifdef CONFIG_PROVE_LOCKING sum_forward_deps += lockdep_count_forward_deps(class); #endif } #ifdef CONFIG_DEBUG_LOCKDEP DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused); #endif seq_printf(m, " lock-classes: %11lu [max: %lu]\n", nr_lock_classes, MAX_LOCKDEP_KEYS); seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", nr_list_entries, MAX_LOCKDEP_ENTRIES); seq_printf(m, " indirect dependencies: %11lu\n", sum_forward_deps); /* * Total number of dependencies: * * All irq-safe locks may nest inside irq-unsafe locks, * plus all the other known dependencies: */ seq_printf(m, " all direct dependencies: %11lu\n", nr_irq_unsafe * nr_irq_safe + nr_hardirq_unsafe * nr_hardirq_safe + nr_list_entries); #ifdef CONFIG_PROVE_LOCKING seq_printf(m, " dependency chains: %11lu [max: %lu]\n", nr_lock_chains, MAX_LOCKDEP_CHAINS); seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n", nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS); #endif #ifdef CONFIG_TRACE_IRQFLAGS seq_printf(m, " in-hardirq chains: %11u\n", nr_hardirq_chains); seq_printf(m, " in-softirq chains: %11u\n", nr_softirq_chains); #endif seq_printf(m, " in-process chains: %11u\n", nr_process_chains); seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n", nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES); seq_printf(m, " combined max dependencies: %11u\n", (nr_hardirq_chains + 1) * (nr_softirq_chains + 1) * (nr_process_chains + 1) ); seq_printf(m, " hardirq-safe locks: %11lu\n", nr_hardirq_safe); seq_printf(m, " hardirq-unsafe locks: %11lu\n", nr_hardirq_unsafe); seq_printf(m, " softirq-safe locks: %11lu\n", nr_softirq_safe); seq_printf(m, " softirq-unsafe locks: %11lu\n", nr_softirq_unsafe); seq_printf(m, " irq-safe locks: %11lu\n", nr_irq_safe); seq_printf(m, " irq-unsafe locks: %11lu\n", nr_irq_unsafe); seq_printf(m, " hardirq-read-safe locks: %11lu\n", nr_hardirq_read_safe); seq_printf(m, " hardirq-read-unsafe locks: %11lu\n", nr_hardirq_read_unsafe); seq_printf(m, " softirq-read-safe locks: %11lu\n", nr_softirq_read_safe);


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