2012-11-14 15:22:49

by Cyrill Gorcunov

Subject: [patch 2/7] fs, eventfd: Add procfs fdinfo helper

This allow us to print out raw counter value.
The /proc/pid/fdinfo/fd output is

| pos: 0
| flags: 04002
| eventfd-count: 5a

Signed-off-by: Cyrill Gorcunov <[email protected]>
CC: Pavel Emelyanov <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Andrey Vagin <[email protected]>
CC: Al Viro <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: Andrew Morton <[email protected]>
CC: James Bottomley <[email protected]>
CC: "Aneesh Kumar K.V" <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: Matthew Helsley <[email protected]>
CC: "J. Bruce Fields" <[email protected]>
CC: "Aneesh Kumar K.V" <[email protected]>
CC: Tvrtko Ursulin <[email protected]>
---
fs/eventfd.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

Index: linux-2.6.git/fs/eventfd.c
===================================================================
--- linux-2.6.git.orig/fs/eventfd.c
+++ linux-2.6.git/fs/eventfd.c
@@ -19,6 +19,8 @@
#include <linux/export.h>
#include <linux/kref.h>
#include <linux/eventfd.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>

struct eventfd_ctx {
struct kref kref;
@@ -284,7 +286,25 @@ static ssize_t eventfd_write(struct file
return res;
}

+#ifdef CONFIG_PROC_FS
+static int eventfd_show_fdinfo(struct seq_file *m, struct file *f)
+{
+ struct eventfd_ctx *ctx = f->private_data;
+ int ret;
+
+ spin_lock_irq(&ctx->wqh.lock);
+ ret = seq_printf(m, "eventfd-count: %16llx\n",
+ (unsigned long long)ctx->count);
+ spin_unlock_irq(&ctx->wqh.lock);
+
+ return ret;
+}
+#endif
+
static const struct file_operations eventfd_fops = {
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = eventfd_show_fdinfo,
+#endif
.release = eventfd_release,
.poll = eventfd_poll,
.read = eventfd_read,

2012-11-15 13:50:04

by Pavel Emelyanov

Subject: Re: [patch 2/7] fs, eventfd: Add procfs fdinfo helper

> This allow us to print out raw counter value.
> The /proc/pid/fdinfo/fd output is
>
> | pos: 0
> | flags: 04002
> | eventfd-count: 5a
>
> Signed-off-by: Cyrill Gorcunov <[email protected]>
> CC: Pavel Emelyanov <[email protected]>
> CC: Oleg Nesterov <[email protected]>
> CC: Andrey Vagin <[email protected]>
> CC: Al Viro <[email protected]>
> CC: Alexey Dobriyan <[email protected]>
> CC: Andrew Morton <[email protected]>
> CC: James Bottomley <[email protected]>
> CC: "Aneesh Kumar K.V" <[email protected]>
> CC: Alexey Dobriyan <[email protected]>
> CC: Matthew Helsley <[email protected]>
> CC: "J. Bruce Fields" <[email protected]>
> CC: "Aneesh Kumar K.V" <[email protected]>
> CC: Tvrtko Ursulin <[email protected]>
> ---

Acked-by: Pavel Emelyanov <[email protected]>