From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Wright <chrisw@sous-sol.org>,
linux-kernel@vger.kernel.org, virtualization@lists.osdl.org,
xen-devel@lists.xensource.com, Andi Kleen <ak@suse.de>,
Andrew Morton <akpm@osdl.org>,
Rusty Russell <rusty@rustcorp.com.au>,
Zachary Amsden <zach@vmware.com>,
Ian Pratt <ian.pratt@xensource.com>,
Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Subject: Re: [RFC PATCH 33/33] Add Xen virtual block device driver.
Date: Tue, 18 Jul 2006 13:57:18 -0700 [thread overview]
Message-ID: <44BD4B2E.2010805@goop.org> (raw)
In-Reply-To: <1153218847.3038.52.camel@laptopd505.fenrus.org>
Arjan van de Ven wrote:
> as first general comment, I think that some of the memory allocation
> GFP_ flags are possibly incorrect; I would expect several places to use
> GFP_NOIO rather than GFP_KERNEL, to avoid recursion/deadlocks
>
>
>> +static void blkif_recover(struct blkfront_info *info)
>>
>> + /* Stage 1: Make a safe copy of the shadow state. */
>> + copy = kmalloc(sizeof(info->shadow), GFP_KERNEL | __GFP_NOFAIL);
>>
>
> like here..
>
>
> and __GFP_NOFAIL is usually horrid; is this because error recovery was
> an afterthought, or because it's physically impossible? In addition
> __GFP_NOFAIL in a block device driver is... an interesting way to add
> OOM deadlocks... have the VM guys looked into this yet?
>
In this particular case, it's only used on the resume path, which I'm
guessing would not lead to IO recursion. There doesn't seem to be any
particular reason for this to be NOFAIL though (but I haven't really
analyzed it).
There don't appear to be any memory allocations on the IO path; they're
all in setup code.
J
next prev parent reply other threads:[~2006-07-18 22:56 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-18 9:18 [RFC PATCH 00/33] Xen i386 paravirtualization support Chris Wright
2006-07-18 7:00 ` [RFC PATCH 01/33] Add apply_to_page_range() function Chris Wright
2006-07-18 10:38 ` Adrian Bunk
2006-07-18 19:29 ` Chris Wright
2006-07-20 6:17 ` Adrian Bunk
2006-07-18 7:00 ` [RFC PATCH 02/33] Add sync bitops Chris Wright
2006-07-18 9:56 ` Arjan van de Ven
2006-07-18 10:18 ` Keir Fraser
2006-07-19 12:54 ` Andi Kleen
2006-07-18 10:34 ` Adrian Bunk
2006-07-18 7:00 ` [RFC PATCH 03/33] Add nosegneg capability to the vsyscall page notes Chris Wright
2006-07-18 7:00 ` [RFC PATCH 04/33] Add XEN config options and disable unsupported config options Chris Wright
2006-07-18 9:59 ` Arjan van de Ven
2006-07-18 10:21 ` Keir Fraser
2006-07-18 7:00 ` [RFC PATCH 05/33] Makefile support to build Xen subarch Chris Wright
2006-07-18 10:00 ` Arjan van de Ven
2006-07-18 11:40 ` Andrew Morton
2006-07-18 20:41 ` Jeremy Fitzhardinge
2006-07-18 20:15 ` Jeremy Fitzhardinge
2006-07-18 7:00 ` [RFC PATCH 06/33] Add Xen interface header files Chris Wright
2006-07-18 7:00 ` [RFC PATCH 07/33] Hypervisor " Chris Wright
2006-07-18 7:00 ` [RFC PATCH 08/33] Add vmlinuz build target Chris Wright
2006-07-18 7:00 ` [RFC PATCH 09/33] Add start-of-day setup hooks to subarch Chris Wright
2006-07-18 10:03 ` Arjan van de Ven
2006-07-18 20:49 ` Jeremy Fitzhardinge
2006-07-20 6:07 ` Adrian Bunk
2006-07-20 12:10 ` Keir Fraser
2006-07-20 13:27 ` Jeremy Fitzhardinge
2006-07-18 7:00 ` [RFC PATCH 10/33] add support for Xen feature queries Chris Wright
2006-07-18 7:00 ` [RFC PATCH 11/33] Add Xen-specific memory management definitions Chris Wright
2006-07-18 7:00 ` [RFC PATCH 12/33] Change __FIXADDR_TOP to leave room for the hypervisor Chris Wright
2006-07-18 7:00 ` [RFC PATCH 13/33] Add a new head.S start-of-day file for booting on Xen Chris Wright
2006-07-18 10:06 ` Arjan van de Ven
2006-07-18 20:13 ` Jeremy Fitzhardinge
2006-07-18 7:00 ` [RFC PATCH 14/33] subarch support for controlling interrupt delivery Chris Wright
2006-07-18 7:00 ` [RFC PATCH 15/33] move segment checks to subarch Chris Wright
2006-07-18 10:09 ` Arjan van de Ven
2006-07-18 11:28 ` Zachary Amsden
2006-07-18 19:06 ` Rusty Russell
2006-07-18 19:25 ` Chris Wright
2006-07-18 20:00 ` [Xen-devel] " Rusty Russell
2006-07-18 7:00 ` [RFC PATCH 16/33] Add support for Xen to entry.S Chris Wright
2006-07-18 10:11 ` Arjan van de Ven
2006-07-18 20:04 ` Jeremy Fitzhardinge
2006-07-18 19:17 ` Rusty Russell
2006-07-18 20:43 ` Chris Wright
2006-07-18 23:03 ` Jeremy Fitzhardinge
2006-07-19 5:30 ` Chris Wright
2006-07-18 7:00 ` [RFC PATCH 17/33] Support loading an initrd when running on Xen Chris Wright
2006-07-18 7:00 ` [RFC PATCH 18/33] Subarch support for CPUID instruction Chris Wright
2006-07-18 10:14 ` Arjan van de Ven
2006-07-18 10:26 ` Keir Fraser
2006-07-18 10:38 ` Arjan van de Ven
2006-07-18 11:33 ` Zachary Amsden
2006-07-18 20:46 ` David Miller
2006-07-18 21:00 ` Chris Wright
2006-07-18 7:00 ` [RFC PATCH 19/33] Support gdt/idt/ldt handling on Xen Chris Wright
2006-07-18 7:00 ` [RFC PATCH 20/33] subarch support for interrupt and exception gates Chris Wright
2006-07-18 7:00 ` [RFC PATCH 21/33] subarch support for control register accesses Chris Wright
2006-07-18 7:00 ` [RFC PATCH 22/33] subarch stack pointer update Chris Wright
2006-07-18 7:00 ` [RFC PATCH 23/33] subarch TLB support Chris Wright
2006-07-18 20:39 ` David Miller
2006-07-18 21:00 ` Chris Wright
2006-07-18 7:00 ` [RFC PATCH 24/33] Add support for Xen event channels Chris Wright
2006-07-18 7:00 ` [RFC PATCH 25/33] Implement timekeeping for Xen Chris Wright
2006-07-25 2:49 ` john stultz
2006-07-25 20:05 ` Jeremy Fitzhardinge
2006-07-18 7:00 ` [RFC PATCH 26/33] subarch suport for idle loop (NO_IDLE_HZ for Xen) Chris Wright
2006-07-18 7:00 ` [RFC PATCH 27/33] Add the Xen virtual console driver Chris Wright
2006-07-18 10:24 ` Arjan van de Ven
2006-07-18 10:31 ` Keir Fraser
2006-07-27 15:05 ` Hollis Blanchard
2006-07-18 7:00 ` [RFC PATCH 28/33] Add Xen grant table support Chris Wright
2006-07-19 10:04 ` [Xen-devel] " Harry Butterworth
2006-07-25 18:30 ` Hollis Blanchard
2006-07-25 18:45 ` Keir Fraser
2006-07-25 19:06 ` Segher Boessenkool
2006-07-18 7:00 ` [RFC PATCH 29/33] Add Xen driver utility functions Chris Wright
2006-07-18 7:00 ` [RFC PATCH 30/33] Add the Xenbus sysfs and virtual device hotplug driver Chris Wright
2006-07-18 7:00 ` [RFC PATCH 31/33] Add Xen subarch reboot support Chris Wright
2006-07-20 6:16 ` Adrian Bunk
2006-07-18 7:00 ` [RFC PATCH 32/33] Add the Xen virtual network device driver Chris Wright
2006-07-18 10:27 ` Arjan van de Ven
2006-07-18 10:35 ` Keir Fraser
2006-07-18 10:42 ` Arjan van de Ven
2006-07-18 12:18 ` Dave Boutcher
2006-07-18 12:39 ` jamal
2006-07-18 13:08 ` Herbert Xu
2006-07-18 13:25 ` John Haller
2006-07-18 15:22 ` Herbert Xu
2006-07-18 15:44 ` Stephen Hemminger
2006-07-19 3:55 ` Herbert Xu
2006-07-18 20:42 ` David Miller
2006-07-18 21:09 ` Chris Wright
2006-07-18 7:00 ` [RFC PATCH 33/33] Add Xen virtual block " Chris Wright
2006-07-18 10:34 ` Arjan van de Ven
2006-07-18 20:57 ` Jeremy Fitzhardinge [this message]
2006-07-18 13:01 ` Dave Boutcher
2006-07-18 16:25 ` Jeff Garzik
2006-07-18 19:28 ` Chris Wright
2006-07-18 21:22 ` Jeremy Fitzhardinge
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