From a10aa579878fc6f9cd17455067380bbdf1d53c91 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 28 Apr 2008 02:12:40 -0700 Subject: [PATCH] vmalloc: show vmalloced areas via /proc/vmallocinfo Implement a new proc file that allows the display of the currently allocated vmalloc memory. It allows to see the users of vmalloc. That is important if vmalloc space is scarce (i386 for example). And it's going to be important for the compound page fallback to vmalloc. Many of the current users can be switched to use compound pages with fallback. This means that the number of users of vmalloc is reduced and page tables no longer necessary to access the memory. /proc/vmallocinfo allows to review how that reduction occurs. If memory becomes fragmented and larger order allocations are no longer possible then /proc/vmallocinfo allows to see which compound page allocations fell back to virtual compound pages. That is important for new users of virtual compound pages. Such as order 1 stack allocation etc that may fallback to virtual compound pages in the future. /proc/vmallocinfo permissions are made readable-only-by-root to avoid possible information leakage. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: CONFIG_MMU=n build fix] Signed-off-by: Christoph Lameter Reviewed-by: KOSAKI Motohiro Cc: Hugh Dickins Cc: Nick Piggin Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/proc_misc.c | 17 +++++++++ include/linux/vmalloc.h | 2 ++ mm/vmalloc.c | 76 ++++++++++++++++++++++++++++++++++++++++- 3 files changed, 94 insertions(+), 1 deletion(-) diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c index 2d563979cb02..441a32f0e5f2 100644 --- a/fs/proc/proc_misc.c +++ b/fs/proc/proc_misc.c @@ -456,6 +456,20 @@ static const struct file_operations proc_slabstats_operations = { #endif #endif +#ifdef CONFIG_MMU +static int vmalloc_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &vmalloc_op); +} + +static const struct file_operations proc_vmalloc_operations = { + .open = vmalloc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif + static int show_stat(struct seq_file *p, void *v) { int i; @@ -868,6 +882,9 @@ void __init proc_misc_init(void) #ifdef CONFIG_DEBUG_SLAB_LEAK create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations); #endif +#endif +#ifdef CONFIG_MMU + proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations); #endif create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations); create_seq_entry("pagetypeinfo", S_IRUGO, &pagetypeinfo_file_ops); diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index ce8e7da05807..7f3adfda337a 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -87,4 +87,6 @@ extern void free_vm_area(struct vm_struct *area); extern rwlock_t vmlist_lock; extern struct vm_struct *vmlist; +extern const struct seq_operations vmalloc_op; + #endif /* _LINUX_VMALLOC_H */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ecf91f8034bf..afa550f66537 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -14,7 +14,7 @@ #include #include #include - +#include #include #include @@ -873,3 +873,77 @@ void free_vm_area(struct vm_struct *area) kfree(area); } EXPORT_SYMBOL_GPL(free_vm_area); + + +#ifdef CONFIG_PROC_FS +static void *s_start(struct seq_file *m, loff_t *pos) +{ + loff_t n = *pos; + struct vm_struct *v; + + read_lock(&vmlist_lock); + v = vmlist; + while (n > 0 && v) { + n--; + v = v->next; + } + if (!n) + return v; + + return NULL; + +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct vm_struct *v = p; + + ++*pos; + return v->next; +} + +static void s_stop(struct seq_file *m, void *p) +{ + read_unlock(&vmlist_lock); +} + +static int s_show(struct seq_file *m, void *p) +{ + struct vm_struct *v = p; + + seq_printf(m, "0x%p-0x%p %7ld", + v->addr, v->addr + v->size, v->size); + + if (v->nr_pages) + seq_printf(m, " pages=%d", v->nr_pages); + + if (v->phys_addr) + seq_printf(m, " phys=%lx", v->phys_addr); + + if (v->flags & VM_IOREMAP) + seq_printf(m, " ioremap"); + + if (v->flags & VM_ALLOC) + seq_printf(m, " vmalloc"); + + if (v->flags & VM_MAP) + seq_printf(m, " vmap"); + + if (v->flags & VM_USERMAP) + seq_printf(m, " user"); + + if (v->flags & VM_VPAGES) + seq_printf(m, " vpages"); + + seq_putc(m, '\n'); + return 0; +} + +const struct seq_operations vmalloc_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; +#endif + -- 2.20.1