From: Vivek Goyal <vgoyal@redhat.com>
To: Baoquan He <bhe@redhat.com>
Cc: mjg59@srcf.ucam.org, greg@kroah.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, ebiederm@xmission.com,
hpa@zytor.com
Subject: Re: [PATCH 4/6] kexec: A new system call, kexec_file_load, for in kernel kexec
Date: Wed, 4 Dec 2013 12:32:39 -0500 [thread overview]
Message-ID: <20131204173238.GD19087@redhat.com> (raw)
In-Reply-To: <20131204015657.GD3298@localhost.localdomain>
On Wed, Dec 04, 2013 at 09:56:57AM +0800, Baoquan He wrote:
> On 11/20/13 at 12:50pm, Vivek Goyal wrote:
> > + * that kexec_mutex is held.
> > + */
>
> I think kexec_add_buffer is guaranteed to be called before allocating
> control pages, why not updating image->control_page after each time
> kexec_add_buffer is called. Then when control page is needed, effective
> address in crash_kernel region can be given. This can be a little more
> efficient.
image->control_page controls the lowest address available for control
pages in crash kernel region. When we do kexec_add_buffer, we don't
necessarily know whether there is an empty page available between
segments or not.
Also, existing logic for kexec does not update the image->control_page
when segments are being copied.
So I think this does not offer any huge benefits and it is not performance
critical path. I will just leave it as it is.
Thanks
Vivek
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WARNING: multiple messages have this Message-ID (diff)
From: Vivek Goyal <vgoyal@redhat.com>
To: Baoquan He <bhe@redhat.com>
Cc: linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
mjg59@srcf.ucam.org, greg@kroah.com, ebiederm@xmission.com,
hpa@zytor.com
Subject: Re: [PATCH 4/6] kexec: A new system call, kexec_file_load, for in kernel kexec
Date: Wed, 4 Dec 2013 12:32:39 -0500 [thread overview]
Message-ID: <20131204173238.GD19087@redhat.com> (raw)
In-Reply-To: <20131204015657.GD3298@localhost.localdomain>
On Wed, Dec 04, 2013 at 09:56:57AM +0800, Baoquan He wrote:
> On 11/20/13 at 12:50pm, Vivek Goyal wrote:
> > + * that kexec_mutex is held.
> > + */
>
> I think kexec_add_buffer is guaranteed to be called before allocating
> control pages, why not updating image->control_page after each time
> kexec_add_buffer is called. Then when control page is needed, effective
> address in crash_kernel region can be given. This can be a little more
> efficient.
image->control_page controls the lowest address available for control
pages in crash kernel region. When we do kexec_add_buffer, we don't
necessarily know whether there is an empty page available between
segments or not.
Also, existing logic for kexec does not update the image->control_page
when segments are being copied.
So I think this does not offer any huge benefits and it is not performance
critical path. I will just leave it as it is.
Thanks
Vivek
next prev parent reply other threads:[~2013-12-04 17:33 UTC|newest]
Thread overview: 180+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-20 17:50 [PATCH 0/6] kexec: A new system call to allow in kernel loading Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 1/6] kexec: Export vmcoreinfo note size properly Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 18:59 ` Greg KH
2013-11-21 18:59 ` Greg KH
2013-11-21 19:08 ` Vivek Goyal
2013-11-21 19:08 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 2/6] kexec: Move segment verification code in a separate function Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 3/6] resource: Provide new functions to walk through resources Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 4/6] kexec: A new system call, kexec_file_load, for in kernel kexec Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 19:03 ` Greg KH
2013-11-21 19:03 ` Greg KH
2013-11-21 19:06 ` Matthew Garrett
2013-11-21 19:06 ` Matthew Garrett
2013-11-21 19:13 ` Vivek Goyal
2013-11-21 19:13 ` Vivek Goyal
2013-11-21 19:19 ` Matthew Garrett
2013-11-21 19:19 ` Matthew Garrett
2013-11-21 19:24 ` Vivek Goyal
2013-11-21 19:24 ` Vivek Goyal
2013-11-22 18:57 ` Vivek Goyal
2013-11-22 18:57 ` Vivek Goyal
2013-11-23 3:39 ` Eric W. Biederman
2013-11-23 3:39 ` Eric W. Biederman
2013-11-25 16:39 ` Vivek Goyal
2013-11-25 16:39 ` Vivek Goyal
2013-11-26 12:23 ` Eric W. Biederman
2013-11-26 12:23 ` Eric W. Biederman
2013-11-26 14:27 ` Vivek Goyal
2013-11-26 14:27 ` Vivek Goyal
2013-12-19 12:54 ` Torsten Duwe
2013-12-19 12:54 ` Torsten Duwe
2013-12-20 14:19 ` Vivek Goyal
2013-12-20 14:19 ` Vivek Goyal
2013-12-20 23:11 ` Eric W. Biederman
2013-12-20 23:11 ` Eric W. Biederman
2013-12-20 23:20 ` Kees Cook
2013-12-20 23:20 ` Kees Cook
2013-12-21 11:38 ` Torsten Duwe
2013-12-21 11:38 ` Torsten Duwe
2014-01-02 20:39 ` Vivek Goyal
2014-01-02 20:39 ` Vivek Goyal
2014-01-02 20:56 ` H. Peter Anvin
2014-01-02 20:56 ` H. Peter Anvin
2014-01-06 21:33 ` Josh Boyer
2014-01-06 21:33 ` Josh Boyer
2014-01-07 4:22 ` H. Peter Anvin
2014-01-07 4:22 ` H. Peter Anvin
2013-12-20 23:20 ` H. Peter Anvin
2013-12-20 23:20 ` H. Peter Anvin
2013-12-21 1:32 ` Eric W. Biederman
2013-12-21 1:32 ` Eric W. Biederman
2013-12-21 3:32 ` H. Peter Anvin
2013-12-21 3:32 ` H. Peter Anvin
2013-12-21 12:15 ` Torsten Duwe
2013-12-21 12:15 ` Torsten Duwe
2013-11-21 19:16 ` Vivek Goyal
2013-11-21 19:16 ` Vivek Goyal
2013-11-22 1:03 ` Kees Cook
2013-11-22 1:03 ` Kees Cook
2013-11-22 2:13 ` Vivek Goyal
2013-11-22 2:13 ` Vivek Goyal
2013-11-22 20:42 ` Jiri Kosina
2013-11-22 20:42 ` Jiri Kosina
2014-01-17 19:17 ` Vivek Goyal
2014-01-17 19:17 ` Vivek Goyal
2013-11-29 3:10 ` Baoquan He
2013-11-29 3:10 ` Baoquan He
2013-12-02 15:27 ` WANG Chao
2013-12-02 15:27 ` WANG Chao
2013-12-02 15:44 ` Vivek Goyal
2013-12-02 15:44 ` Vivek Goyal
2013-12-04 1:35 ` Baoquan He
2013-12-04 1:35 ` Baoquan He
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 1:56 ` Baoquan He
2013-12-04 1:56 ` Baoquan He
2013-12-04 8:19 ` Baoquan He
2013-12-04 8:19 ` Baoquan He
2013-12-04 17:32 ` Vivek Goyal [this message]
2013-12-04 17:32 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 5/6] kexec-bzImage: Support for loading bzImage using 64bit entry Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 19:07 ` Greg KH
2013-11-21 19:07 ` Greg KH
2013-11-21 19:21 ` Vivek Goyal
2013-11-21 19:21 ` Vivek Goyal
2013-11-22 15:24 ` H. Peter Anvin
2013-11-22 15:24 ` H. Peter Anvin
2013-11-28 11:35 ` Baoquan He
2013-11-28 11:35 ` Baoquan He
2013-12-02 15:36 ` Vivek Goyal
2013-12-02 15:36 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 6/6] kexec: Support for Kexec on panic using new system call Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-28 11:28 ` Baoquan He
2013-11-28 11:28 ` Baoquan He
2013-12-02 15:30 ` Vivek Goyal
2013-12-02 15:30 ` Vivek Goyal
2013-12-04 1:51 ` Baoquan He
2013-12-04 1:51 ` Baoquan He
2013-12-04 17:20 ` Vivek Goyal
2013-12-04 17:20 ` Vivek Goyal
2013-12-04 1:41 ` Baoquan He
2013-12-04 1:41 ` Baoquan He
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 17:19 ` Vivek Goyal
2013-11-21 18:58 ` [PATCH 0/6] kexec: A new system call to allow in kernel loading Greg KH
2013-11-21 18:58 ` Greg KH
2013-11-21 19:07 ` Vivek Goyal
2013-11-21 19:07 ` Vivek Goyal
2013-11-21 19:46 ` Vivek Goyal
2013-11-21 19:46 ` Vivek Goyal
2013-11-21 19:06 ` Geert Uytterhoeven
2013-11-21 19:06 ` Geert Uytterhoeven
2013-11-21 19:14 ` Vivek Goyal
2013-11-21 19:14 ` Vivek Goyal
2013-11-21 23:07 ` Eric W. Biederman
2013-11-21 23:07 ` Eric W. Biederman
2013-11-22 1:28 ` H. Peter Anvin
2013-11-22 1:28 ` H. Peter Anvin
2013-11-22 2:35 ` Vivek Goyal
2013-11-22 2:35 ` Vivek Goyal
2013-11-22 2:40 ` H. Peter Anvin
2013-11-22 2:40 ` H. Peter Anvin
2013-11-22 1:55 ` Vivek Goyal
2013-11-22 1:55 ` Vivek Goyal
2013-11-22 9:09 ` Geert Uytterhoeven
2013-11-22 9:09 ` Geert Uytterhoeven
2013-11-22 13:30 ` Jiri Kosina
2013-11-22 13:30 ` Jiri Kosina
2013-11-22 13:46 ` Vivek Goyal
2013-11-22 13:46 ` Vivek Goyal
2013-11-22 13:50 ` Jiri Kosina
2013-11-22 13:50 ` Jiri Kosina
2013-11-22 15:33 ` Vivek Goyal
2013-11-22 15:33 ` Vivek Goyal
2013-11-22 17:45 ` Kees Cook
2013-11-22 17:45 ` Kees Cook
2013-11-22 13:43 ` Vivek Goyal
2013-11-22 13:43 ` Vivek Goyal
2013-11-22 15:25 ` Geert Uytterhoeven
2013-11-22 15:25 ` Geert Uytterhoeven
2013-11-22 15:33 ` Jiri Kosina
2013-11-22 15:33 ` Jiri Kosina
2013-11-22 15:57 ` Eric Paris
2013-11-22 15:57 ` Eric Paris
2013-11-22 16:04 ` Jiri Kosina
2013-11-22 16:04 ` Jiri Kosina
2013-11-22 16:08 ` Vivek Goyal
2013-11-22 16:08 ` Vivek Goyal
2013-11-22 13:34 ` Eric W. Biederman
2013-11-22 13:34 ` Eric W. Biederman
2013-11-22 14:19 ` Vivek Goyal
2013-11-22 14:19 ` Vivek Goyal
2013-11-22 19:48 ` Greg KH
2013-11-22 19:48 ` Greg KH
2013-11-23 3:23 ` Eric W. Biederman
2013-11-23 3:23 ` Eric W. Biederman
2013-12-04 19:34 ` Vivek Goyal
2013-12-04 19:34 ` Vivek Goyal
2013-12-05 4:10 ` Eric W. Biederman
2013-12-05 4:10 ` Eric W. Biederman
2013-11-25 10:04 ` Michael Holzheu
2013-11-25 10:04 ` Michael Holzheu
2013-11-25 15:36 ` Vivek Goyal
2013-11-25 15:36 ` Vivek Goyal
2013-11-25 16:15 ` Michael Holzheu
2013-11-25 16:15 ` Michael Holzheu
2013-11-22 0:55 ` HATAYAMA Daisuke
2013-11-22 0:55 ` HATAYAMA Daisuke
2013-11-22 2:03 ` Vivek Goyal
2013-11-22 2:03 ` Vivek Goyal
2013-12-03 13:23 ` Baoquan He
2013-12-03 13:23 ` Baoquan He
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