From: Cyrill Gorcunov <gorcunov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Michael Kerrisk
<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>,
Cyrill Gorcunov
<gorcunov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Andrey Vagin <avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>,
Pavel Emelyanov <xemul-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>,
Vladimir Davydov
<vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
Subject: [patch 1/4] timerfd: Implement show_fdinfo method
Date: Wed, 16 Jul 2014 01:54:52 +0400 [thread overview]
Message-ID: <20140715215703.114365649@openvz.org> (raw)
In-Reply-To: 20140715215451.499191426@openvz.org
[-- Attachment #1: timerfd-show-fdinfo-5 --]
[-- Type: text/plain, Size: 3280 bytes --]
For checkpoint/restore of timerfd files we need to know how exactly
the timer were armed, to be able to recreate it on restore stage.
Thus implement show_fdinfo method which provides enough information
for that.
One of significant changes I think is the addition of @settime_flags
member. Currently there are two flags TFD_TIMER_ABSTIME and
TFD_TIMER_CANCEL_ON_SET, and the second can be found from
@might_cancel variable but in case if the flags will be extended
in future we most probably will have to somehow remember them
explicitly anyway so I guss doing that right now won't hurt.
To not bloat the timerfd_ctx structure I've converted @expired
to short integer and defined @settime_flags as short too.
v2 (by avagin@, vdavydov@ and tglx@):
- Add it_value/it_interval fields
- Save flags being used in timerfd_setup in context
v3 (by tglx@):
- don't forget to use CONFIG_PROC_FS
v4 (by akpm@):
-Use define timerfd_show NULL for non c/r config
CC: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
CC: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
CC: Andrey Vagin <avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
CC: Pavel Emelyanov <xemul-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
CC: Vladimir Davydov <vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
Signed-off-by: Cyrill Gorcunov <gorcunov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
---
fs/timerfd.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
Index: linux-2.6.git/fs/timerfd.c
===================================================================
--- linux-2.6.git.orig/fs/timerfd.c
+++ linux-2.6.git/fs/timerfd.c
@@ -35,8 +35,9 @@ struct timerfd_ctx {
ktime_t moffs;
wait_queue_head_t wqh;
u64 ticks;
- int expired;
int clockid;
+ short unsigned expired;
+ short unsigned settime_flags; /* to show in fdinfo */
struct rcu_head rcu;
struct list_head clist;
bool might_cancel;
@@ -196,6 +197,8 @@ static int timerfd_setup(struct timerfd_
if (timerfd_canceled(ctx))
return -ECANCELED;
}
+
+ ctx->settime_flags = flags & TFD_SETTIME_FLAGS;
return 0;
}
@@ -284,11 +287,40 @@ static ssize_t timerfd_read(struct file
return res;
}
+#ifdef CONFIG_PROC_FS
+static int timerfd_show(struct seq_file *m, struct file *file)
+{
+ struct timerfd_ctx *ctx = file->private_data;
+ struct itimerspec t;
+
+ spin_lock_irq(&ctx->wqh.lock);
+ t.it_value = ktime_to_timespec(timerfd_get_remaining(ctx));
+ t.it_interval = ktime_to_timespec(ctx->tintv);
+ spin_unlock_irq(&ctx->wqh.lock);
+
+ return seq_printf(m,
+ "clockid: %d\n"
+ "ticks: %llu\n"
+ "settime flags: 0%o\n"
+ "it_value: (%llu, %llu)\n"
+ "it_interval: (%llu, %llu)\n",
+ ctx->clockid, (unsigned long long)ctx->ticks,
+ ctx->settime_flags,
+ (unsigned long long)t.it_value.tv_sec,
+ (unsigned long long)t.it_value.tv_nsec,
+ (unsigned long long)t.it_interval.tv_sec,
+ (unsigned long long)t.it_interval.tv_nsec);
+}
+#else
+#define timerfd_show NULL
+#endif
+
static const struct file_operations timerfd_fops = {
.release = timerfd_release,
.poll = timerfd_poll,
.read = timerfd_read,
.llseek = noop_llseek,
+ .show_fdinfo = timerfd_show,
};
static int timerfd_fget(int fd, struct fd *p)
next prev parent reply other threads:[~2014-07-15 21:54 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-15 21:54 [patch 0/4] timerfd c/r support, v5 Cyrill Gorcunov
2014-07-15 21:54 ` Cyrill Gorcunov [this message]
2014-07-15 21:54 ` [patch 2/4] docs: procfs -- Document timerfd output Cyrill Gorcunov
2014-07-15 21:54 ` [patch 3/4] timerfd: Implement timerfd_ioctl method to restore timerfd_ctx::ticks, v3 Cyrill Gorcunov
2014-07-15 21:54 ` [patch 4/4] timerfd.2: Add ioctl method description Cyrill Gorcunov
[not found] ` <20140715215703.353177995-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2015-04-13 19:56 ` Michael Kerrisk (man-pages)
[not found] ` <552C1F64.30202-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-04-13 20:10 ` Cyrill Gorcunov
-- strict thread matches above, loose matches on Subject: below --
2014-06-23 18:54 [patch 0/4] timerfd c/r support, v4 Cyrill Gorcunov
2014-06-23 18:54 ` [patch 1/4] timerfd: Implement show_fdinfo method Cyrill Gorcunov
[not found] ` <20140623190345.354980826-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2014-06-24 22:02 ` Cyrill Gorcunov
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