From: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Subject: [PATCH] proc: add /proc/kpagetype interface
This makes page pageblock type information available to the user-space.
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
fs/proc/page.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
Index: b/fs/proc/page.c
===================================================================
--- a/fs/proc/page.c 2012-05-31 16:30:49.215109568 +0200
+++ b/fs/proc/page.c 2012-05-31 16:30:50.559109495 +0200
@@ -254,11 +254,59 @@ static const struct file_operations proc
.read = kpageorder_read,
};
+static ssize_t kpagetype_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ u64 __user *out = (u64 __user *)buf;
+ struct page *ppage;
+ unsigned long src = *ppos;
+ unsigned long pfn;
+ ssize_t ret = 0;
+ u64 ptype;
+
+ pfn = src / KPMSIZE;
+ count = min_t(unsigned long, count,
+ ((ARCH_PFN_OFFSET + max_pfn) * KPMSIZE) - src);
+ if (src & KPMMASK || count & KPMMASK)
+ return -EINVAL;
+
+ while (count > 0) {
+ if (pfn_valid(pfn))
+ ppage = pfn_to_page(pfn);
+ else
+ ppage = NULL;
+ if (!ppage)
+ ptype = 0;
+ else
+ ptype = get_pageblock_migratetype(ppage);
+
+ if (put_user(ptype, out)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ pfn++;
+ out++;
+ count -= KPMSIZE;
+ }
+
+ *ppos += (char __user *)out - buf;
+ if (!ret)
+ ret = (char __user *)out - buf;
+ return ret;
+}
+
+static const struct file_operations proc_kpagetype_operations = {
+ .llseek = mem_lseek,
+ .read = kpagetype_read,
+};
+
static int __init proc_page_init(void)
{
proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
proc_create("kpageorder", S_IRUSR, NULL, &proc_kpageorder_operations);
+ proc_create("kpagetype", S_IRUSR, NULL, &proc_kpagetype_operations);
return 0;
}
module_init(proc_page_init);
--
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