All of lore.kernel.org
 help / color / mirror / Atom feed
From: Wu Fengguang <fengguang.wu@intel.com>
To: David Miller <davem@davemloft.net>
Cc: "herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org"
	<herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage
Date: Wed, 15 Jul 2009 15:45:03 +0800	[thread overview]
Message-ID: <20090715074503.GC6145@localhost> (raw)
In-Reply-To: <20090714.090432.13343695.davem@davemloft.net>

On Wed, Jul 15, 2009 at 12:04:32AM +0800, David Miller wrote:
> From: Herbert Xu <herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
> Date: Fri, 10 Jul 2009 16:02:47 +0800
> 
> > On Fri, Jul 10, 2009 at 04:00:17PM +0800, Wu Fengguang wrote:
> >> 
> >> The (sk_allocation & ~__GFP_WAIT) cases should be rare, but I guess
> >> the networking code shall do it anyway, because sk_allocation defaults
> >> to GFP_KERNEL. It seems that currently the networking code simply uses
> >> a lot of GFP_ATOMIC, do they really mean "I cannot sleep"?
> > 
> > Yep because they're done from softirq context.
> 
> Yes, this is the core issue.

Yes, that's general true. But..

> All of Wu's talk about how "GFP_ATOMIC will wake up kswapd and
> therefore can succeed just as well as GFP_KERNEL" is not relevant,
> because GFP_ATOMIC means sleeping is not allowed.

We are talking about tcp_send_fin() here, which can sleep.

Thanks,
Fengguang

WARNING: multiple messages have this Message-ID (diff)
From: Wu Fengguang <fengguang.wu@intel.com>
To: David Miller <davem@davemloft.net>
Cc: "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage
Date: Wed, 15 Jul 2009 15:45:03 +0800	[thread overview]
Message-ID: <20090715074503.GC6145@localhost> (raw)
In-Reply-To: <20090714.090432.13343695.davem@davemloft.net>

On Wed, Jul 15, 2009 at 12:04:32AM +0800, David Miller wrote:
> From: Herbert Xu <herbert@gondor.apana.org.au>
> Date: Fri, 10 Jul 2009 16:02:47 +0800
> 
> > On Fri, Jul 10, 2009 at 04:00:17PM +0800, Wu Fengguang wrote:
> >> 
> >> The (sk_allocation & ~__GFP_WAIT) cases should be rare, but I guess
> >> the networking code shall do it anyway, because sk_allocation defaults
> >> to GFP_KERNEL. It seems that currently the networking code simply uses
> >> a lot of GFP_ATOMIC, do they really mean "I cannot sleep"?
> > 
> > Yep because they're done from softirq context.
> 
> Yes, this is the core issue.

Yes, that's general true. But..

> All of Wu's talk about how "GFP_ATOMIC will wake up kswapd and
> therefore can succeed just as well as GFP_KERNEL" is not relevant,
> because GFP_ATOMIC means sleeping is not allowed.

We are talking about tcp_send_fin() here, which can sleep.

Thanks,
Fengguang

WARNING: multiple messages have this Message-ID (diff)
From: Wu Fengguang <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: "herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org"
	<herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage
Date: Wed, 15 Jul 2009 15:45:03 +0800	[thread overview]
Message-ID: <20090715074503.GC6145@localhost> (raw)
In-Reply-To: <20090714.090432.13343695.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>

On Wed, Jul 15, 2009 at 12:04:32AM +0800, David Miller wrote:
> From: Herbert Xu <herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
> Date: Fri, 10 Jul 2009 16:02:47 +0800
> 
> > On Fri, Jul 10, 2009 at 04:00:17PM +0800, Wu Fengguang wrote:
> >> 
> >> The (sk_allocation & ~__GFP_WAIT) cases should be rare, but I guess
> >> the networking code shall do it anyway, because sk_allocation defaults
> >> to GFP_KERNEL. It seems that currently the networking code simply uses
> >> a lot of GFP_ATOMIC, do they really mean "I cannot sleep"?
> > 
> > Yep because they're done from softirq context.
> 
> Yes, this is the core issue.

Yes, that's general true. But..

> All of Wu's talk about how "GFP_ATOMIC will wake up kswapd and
> therefore can succeed just as well as GFP_KERNEL" is not relevant,
> because GFP_ATOMIC means sleeping is not allowed.

We are talking about tcp_send_fin() here, which can sleep.

Thanks,
Fengguang
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2009-07-15  7:45 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-08  2:37 sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage Wu Fengguang
2009-06-08  2:37 ` Wu Fengguang
2009-06-08  4:55 ` KOSAKI Motohiro
2009-06-08  4:55   ` KOSAKI Motohiro
2009-06-08  4:55   ` KOSAKI Motohiro
2009-06-08  5:00   ` Wu Fengguang
2009-06-08  5:07     ` KOSAKI Motohiro
2009-06-08  5:07       ` KOSAKI Motohiro
2009-06-08  5:07       ` KOSAKI Motohiro
     [not found]       ` <20090608140529.4376.A69D9226-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2009-06-08  5:53         ` Wu Fengguang
2009-06-08  5:53           ` Wu Fengguang
2009-06-08  5:53           ` Wu Fengguang
2009-06-08  5:56           ` Wu Fengguang
2009-06-08  5:56             ` Wu Fengguang
2009-06-08  5:56             ` Wu Fengguang
2009-06-08  6:12             ` KOSAKI Motohiro
2009-06-08  6:12               ` KOSAKI Motohiro
2009-06-08  6:12               ` KOSAKI Motohiro
     [not found]   ` <20090608134428.4373.A69D9226-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2009-06-09  3:07     ` Wu Fengguang
2009-06-09  3:07       ` Wu Fengguang
2009-06-09  3:07       ` Wu Fengguang
2009-06-09  3:15       ` KOSAKI Motohiro
2009-06-09  3:15         ` KOSAKI Motohiro
2009-06-09  3:15         ` KOSAKI Motohiro
2009-07-06 10:52 ` Herbert Xu
2009-07-06 10:52   ` Herbert Xu
2009-07-06 10:52   ` Herbert Xu
2009-07-09 13:17   ` Wu Fengguang
2009-07-10  0:13     ` David Miller
2009-07-10  0:13       ` David Miller
2009-07-10  0:13       ` David Miller
2009-07-10  0:59       ` Herbert Xu
2009-07-10  0:59         ` Herbert Xu
2009-07-10  0:59         ` Herbert Xu
2009-07-10  8:00       ` Wu Fengguang
2009-07-10  8:00         ` Wu Fengguang
2009-07-10  8:00         ` Wu Fengguang
2009-07-10  8:02         ` Herbert Xu
     [not found]           ` <20090710080247.GA2693-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2009-07-14 16:04             ` David Miller
2009-07-14 16:04               ` David Miller
2009-07-14 16:04               ` David Miller
2009-07-15  7:45               ` Wu Fengguang [this message]
2009-07-15  7:45                 ` Wu Fengguang
2009-07-15  7:45                 ` Wu Fengguang

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=20090715074503.GC6145@localhost \
    --to=fengguang.wu@intel.com \
    --cc=davem@davemloft.net \
    --cc=herbert-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /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.