From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: RT <linux-rt-users@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH] rt/aio: fix rcu garbage collection might_sleep() splat
Date: Mon, 09 Jun 2014 08:22:08 +0200 [thread overview]
Message-ID: <1402294928.6316.38.camel@marge.simpson.net> (raw)
In-Reply-To: <1402283822.5195.3.camel@marge.simpson.net>
On Mon, 2014-06-09 at 05:17 +0200, Mike Galbraith wrote:
> On Mon, 2014-06-09 at 10:08 +0800, Lai Jiangshan wrote:
> > Hi, rt-people
> >
> > I don't think it is the correct direction.
>
> Yup, it's a band-aid, ergo RFC.
Making aio play by the rules is safe. Another option is to bend the
rules up a little. With the below, ltp aio-stress testcases haven't yet
griped or exploded either.. which somehow isn't quite as comforting as
"is safe" :)
---
fs/aio.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -509,7 +509,9 @@ static void free_ioctx_reqs(struct percp
struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
INIT_WORK(&ctx->free_work, free_ioctx);
+ preempt_enable_rt();
schedule_work(&ctx->free_work);
+ preempt_disable_rt();
}
/*
@@ -522,7 +524,9 @@ static void free_ioctx_users(struct perc
struct kioctx *ctx = container_of(ref, struct kioctx, users);
struct kiocb *req;
+ preempt_enable_rt();
spin_lock_irq(&ctx->ctx_lock);
+ local_irq_disable_rt();
while (!list_empty(&ctx->active_reqs)) {
req = list_first_entry(&ctx->active_reqs,
@@ -536,6 +540,8 @@ static void free_ioctx_users(struct perc
percpu_ref_kill(&ctx->reqs);
percpu_ref_put(&ctx->reqs);
+ preempt_disable_rt();
+ local_irq_enable_rt();
}
static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
next prev parent reply other threads:[~2014-06-09 6:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-08 8:35 [RFC PATCH] rt/aio: fix rcu garbage collection might_sleep() splat Mike Galbraith
2014-06-09 2:08 ` Lai Jiangshan
2014-06-09 3:17 ` Mike Galbraith
2014-06-09 6:22 ` Mike Galbraith [this message]
2014-06-09 9:04 ` Pavel Vasilyev
2014-06-10 3:47 ` [RFC PATCH V2] " Mike Galbraith
2014-06-10 17:50 ` Benjamin LaHaise
2014-06-11 4:10 ` Mike Galbraith
2014-06-12 20:26 ` Kent Overstreet
2014-06-25 15:24 ` Benjamin LaHaise
2014-06-26 7:37 ` Mike Galbraith
2014-06-26 16:42 ` Benjamin LaHaise
2015-02-16 17:59 ` Sebastian Andrzej Siewior
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1402294928.6316.38.camel@marge.simpson.net \
--to=umgwanakikbuti@gmail.com \
--cc=bigeasy@linutronix.de \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.