Re: [PATCH 3/4] kcore: build physical memory direct map informationin proper way

From: KAMEZAWA Hiroyuki
Date: Wed Jul 22 2009 - 02:09:58 EST


On Wed, 22 Jul 2009 14:09:00 +0800
Amerigo Wang <xiyou.wangcong@xxxxxxxxx> wrote:

> >+static int kcore_update_ram(void)
> >+{
> >+ LIST_HEAD(head);
> >+ struct kcore_list *ent;
> >+ int ret = 0;
> >+
> >+ ent = kmalloc(sizeof(*head), GFP_KERNEL);
>
yes, of course.

>
> Shouldn't it be sizeof(*ent)? :)
>
>
> >+ if (!ent) {
> >+ ret = -ENOMEM;
> >+ goto unlock_out;
>
>
> Where is unlock_out? :)
>
>

Hmm...garbage from old patch, sorry.


> >+ }
> >+ ent->addr = __va(0);
> >+ ent->size = max_low_pfn << PAGE_SHIFT;
> >+ ent->type = SYSTEM_RAM;
>
>
> Huh? SYSTEM_RAM or KCORE_RAM?
>
>

KCORE_RAM ... ah, ok. I tested only on x86-64 and this HIGHMEM is wasn't
compiled. Very sorry.

I"ll post fixed one soon.

Thanks,
-Kame


> >+ list_add(&ent->list, &head);
> >+ __kcore_update_ram(&head);
> >+ return ret;
> >+}
> >+
> >+#else /* !CONFIG_HIGHMEM */
> >+
> >+static int
> >+kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
> >+{
> >+ struct list_head *head = (struct list_head *)arg;
> >+ struct kcore_list *ent;
> >+
> >+ ent = kmalloc(sizeof(*ent), GFP_KERNEL);
> >+ if (!ent)
> >+ return -ENOMEM;
> >+ ent->addr = (unsigned long)__va((pfn << PAGE_SHIFT));
> >+ ent->size = nr_pages << PAGE_SHIFT;
> >+ ent->type = KCORE_RAM;
> >+ list_add(&ent->list, head);
> >+ return 0;
> >+}
> >+
> >+static int kcore_update_ram(void)
> >+{
> >+ int nid, ret;
> >+ unsigned long end_pfn;
> >+ LIST_HEAD(head);
> >+
> >+ /* Not inialized....update now */
> >+ /* find out "max pfn" */
> >+ end_pfn = 0;
> >+ for_each_node_state(nid, N_HIGH_MEMORY)
> >+ if (end_pfn < node_end_pfn(nid))
> >+ end_pfn = node_end_pfn(nid);
> >+ /* scan 0 to max_pfn */
> >+ ret = walk_memory_resource(0, end_pfn, &head, kclist_add_private);
> >+ if (ret) {
> >+ free_kclist_ents(&head);
> >+ return -ENOMEM;
> >+ }
> >+ __kcore_update_ram(&head);
> >+ return ret;
> >+}
> >+#endif /* CONFIG_HIGH_MEM */
> >
> > /*****************************************************************************/
> > /*
> >@@ -271,6 +362,11 @@ read_kcore(struct file *file, char __use
> > read_unlock(&kclist_lock);
> > return 0;
> > }
> >+ /* memory hotplug ?? */
> >+ if (kcore_need_update) {
> >+ read_unlock(&kclist_lock);
> >+ return -EBUSY;
> >+ }
> >
> > /* trim buflen to not go beyond EOF */
> > if (buflen > size - *fpos)
> >@@ -406,9 +502,42 @@ read_kcore(struct file *file, char __use
> > return acc;
> > }
> >
> >+static int open_kcore(struct inode * inode, struct file *filp)
> >+{
> >+ if (!capable(CAP_SYS_RAWIO))
> >+ return -EPERM;
> >+ if (kcore_need_update)
> >+ kcore_update_ram();
> >+ return 0;
> >+}
> >+
> >+
> >+static const struct file_operations proc_kcore_operations = {
> >+ .read = read_kcore,
> >+ .open = open_kcore,
> >+};
> >+
> >+/* just remember that we have to update kcore */
> >+static int __meminit kcore_callback(struct notifier_block *self,
> >+ unsigned long action, void *arg)
> >+{
> >+ switch (action) {
> >+ case MEM_ONLINE:
> >+ case MEM_OFFLINE:
> >+ write_lock(&kclist_lock);
> >+ kcore_need_update = 1;
> >+ write_unlock(&kclist_lock);
> >+ }
> >+ return NOTIFY_OK;
> >+}
> >+
> >+
> > static int __init proc_kcore_init(void)
> > {
> > proc_root_kcore = proc_create("kcore", S_IRUSR, NULL, &proc_kcore_operations);
> >+ kcore_update_ram();
> >+ hotplug_memory_notifier(kcore_callback, 0);
> > return 0;
> > }
> > module_init(proc_kcore_init);
> >+
> >Index: mmotm-2.6.31-Jul16/include/linux/ioport.h
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/include/linux/ioport.h
> >+++ mmotm-2.6.31-Jul16/include/linux/ioport.h
> >@@ -186,5 +186,13 @@ extern void __devm_release_region(struct
> > extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
> > extern int iomem_is_exclusive(u64 addr);
> >
> >+/*
> >+ * Walk through all SYSTEM_RAM which is registered as resource.
> >+ * arg is (start_pfn, nr_pages, private_arg_pointer)
> >+ */
> >+extern int walk_memory_resource(unsigned long start_pfn,
> >+ unsigned long nr_pages, void *arg,
> >+ int (*func)(unsigned long, unsigned long, void *));
> >+
> > #endif /* __ASSEMBLY__ */
> > #endif /* _LINUX_IOPORT_H */
> >Index: mmotm-2.6.31-Jul16/include/linux/memory_hotplug.h
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/include/linux/memory_hotplug.h
> >+++ mmotm-2.6.31-Jul16/include/linux/memory_hotplug.h
> >@@ -191,13 +191,6 @@ static inline void register_page_bootmem
> >
> > #endif /* ! CONFIG_MEMORY_HOTPLUG */
> >
> >-/*
> >- * Walk through all memory which is registered as resource.
> >- * arg is (start_pfn, nr_pages, private_arg_pointer)
> >- */
> >-extern int walk_memory_resource(unsigned long start_pfn,
> >- unsigned long nr_pages, void *arg,
> >- int (*func)(unsigned long, unsigned long, void *));
> >
> > #ifdef CONFIG_MEMORY_HOTREMOVE
> >
> >Index: mmotm-2.6.31-Jul16/kernel/resource.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/kernel/resource.c
> >+++ mmotm-2.6.31-Jul16/kernel/resource.c
> >@@ -234,7 +234,7 @@ int release_resource(struct resource *ol
> >
> > EXPORT_SYMBOL(release_resource);
> >
> >-#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
> >+#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
> > /*
> > * Finds the lowest memory reosurce exists within [res->start.res->end)
> > * the caller must specify res->start, res->end, res->flags.
> >Index: mmotm-2.6.31-Jul16/arch/ia64/mm/init.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/ia64/mm/init.c
> >+++ mmotm-2.6.31-Jul16/arch/ia64/mm/init.c
> >@@ -639,7 +639,6 @@ mem_init (void)
> >
> > high_memory = __va(max_low_pfn * PAGE_SIZE);
> >
> >- kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE, KCORE_RAM);
> > kclist_add(&kcore_vmem, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> > kclist_add(&kcore_kernel, _stext, _end - _stext, KCORE_TEXT);
> >Index: mmotm-2.6.31-Jul16/arch/mips/mm/init.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/mips/mm/init.c
> >+++ mmotm-2.6.31-Jul16/arch/mips/mm/init.c
> >@@ -412,7 +412,6 @@ void __init mem_init(void)
> > kclist_add(&kcore_kseg0, (void *) CKSEG0,
> > 0x80000000 - 4, KCORE_TEXT);
> > #endif
> >- kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT, KCORE_RAM);
> > kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> >
> >Index: mmotm-2.6.31-Jul16/arch/powerpc/mm/init_32.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/powerpc/mm/init_32.c
> >+++ mmotm-2.6.31-Jul16/arch/powerpc/mm/init_32.c
> >@@ -249,30 +249,6 @@ static struct kcore_list kcore_vmem;
> >
> > static int __init setup_kcore(void)
> > {
> >- int i;
> >-
> >- for (i = 0; i < lmb.memory.cnt; i++) {
> >- unsigned long base;
> >- unsigned long size;
> >- struct kcore_list *kcore_mem;
> >-
> >- base = lmb.memory.region[i].base;
> >- size = lmb.memory.region[i].size;
> >-
> >- kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC);
> >- if (!kcore_mem)
> >- panic("%s: kmalloc failed\n", __func__);
> >-
> >- /* must stay under 32 bits */
> >- if ( 0xfffffffful - (unsigned long)__va(base) < size) {
> >- size = 0xfffffffful - (unsigned long)(__va(base));
> >- printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n",
> >- size);
> >- }
> >-
> >- kclist_add(kcore_mem, __va(base), size, KCORE_RAM);
> >- }
> >-
> > kclist_add(&kcore_vmem, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> >
> >Index: mmotm-2.6.31-Jul16/arch/powerpc/mm/init_64.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/powerpc/mm/init_64.c
> >+++ mmotm-2.6.31-Jul16/arch/powerpc/mm/init_64.c
> >@@ -114,23 +114,6 @@ static struct kcore_list kcore_vmem;
> >
> > static int __init setup_kcore(void)
> > {
> >- int i;
> >-
> >- for (i=0; i < lmb.memory.cnt; i++) {
> >- unsigned long base, size;
> >- struct kcore_list *kcore_mem;
> >-
> >- base = lmb.memory.region[i].base;
> >- size = lmb.memory.region[i].size;
> >-
> >- /* GFP_ATOMIC to avoid might_sleep warnings during boot */
> >- kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC);
> >- if (!kcore_mem)
> >- panic("%s: kmalloc failed\n", __func__);
> >-
> >- kclist_add(kcore_mem, __va(base), size, KCORE_RAM);
> >- }
> >-
> > kclist_add(&kcore_vmem, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> >
> >Index: mmotm-2.6.31-Jul16/arch/sh/mm/init.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/sh/mm/init.c
> >+++ mmotm-2.6.31-Jul16/arch/sh/mm/init.c
> >@@ -218,7 +218,6 @@ void __init mem_init(void)
> > datasize = (unsigned long) &_edata - (unsigned long) &_etext;
> > initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
> >
> >- kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT, KCORE_RAM);
> > kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
> > VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
> >
> >Index: mmotm-2.6.31-Jul16/arch/x86/mm/init_32.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/x86/mm/init_32.c
> >+++ mmotm-2.6.31-Jul16/arch/x86/mm/init_32.c
> >@@ -886,7 +886,6 @@ void __init mem_init(void)
> > datasize = (unsigned long) &_edata - (unsigned long) &_etext;
> > initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
> >
> >- kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT, KCORE_RAM);
> > kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> >
> >Index: mmotm-2.6.31-Jul16/arch/x86/mm/init_64.c
> >===================================================================
> >--- mmotm-2.6.31-Jul16.orig/arch/x86/mm/init_64.c
> >+++ mmotm-2.6.31-Jul16/arch/x86/mm/init_64.c
> >@@ -677,7 +677,6 @@ void __init mem_init(void)
> > initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
> >
> > /* Register memory areas for /proc/kcore */
> >- kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT, KCORE_RAM);
> > kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
> > VMALLOC_END-VMALLOC_START, KCORE_VMALLOC);
> > kclist_add(&kcore_kernel, &_stext, _end - _stext, KCORE_TEXT);
> >
> >--
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