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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

  parent reply	other threads:[~2013-12-04 17:33 UTC|newest]

Thread overview: 90+ 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 ` [PATCH 1/6] kexec: Export vmcoreinfo note size properly Vivek Goyal
2013-11-21 18:59   ` Greg KH
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 ` [PATCH 3/6] resource: Provide new functions to walk through resources Vivek Goyal
2013-11-20 17:50 ` [PATCH 4/6] kexec: A new system call, kexec_file_load, for in kernel kexec Vivek Goyal
2013-11-21 19:03   ` Greg KH
2013-11-21 19:06     ` Matthew Garrett
2013-11-21 19:13       ` Vivek Goyal
2013-11-21 19:19         ` Matthew Garrett
2013-11-21 19:24           ` Vivek Goyal
2013-11-22 18:57           ` Vivek Goyal
2013-11-23  3:39             ` Eric W. Biederman
2013-11-25 16:39               ` Vivek Goyal
2013-11-26 12:23                 ` Eric W. Biederman
2013-11-26 14:27                   ` Vivek Goyal
2013-12-19 12:54                     ` Torsten Duwe
2013-12-20 14:19                       ` Vivek Goyal
2013-12-20 23:11                         ` Eric W. Biederman
2013-12-20 23:20                           ` Kees Cook
2013-12-21 11:38                             ` Torsten Duwe
2014-01-02 20:39                             ` Vivek Goyal
2014-01-02 20:56                               ` H. Peter Anvin
2014-01-06 21:33                                 ` Josh Boyer
2014-01-07  4:22                                   ` H. Peter Anvin
2013-12-20 23:20                           ` H. Peter Anvin
2013-12-21  1:32                             ` Eric W. Biederman
2013-12-21  3:32                               ` H. Peter Anvin
2013-12-21 12:15                                 ` Torsten Duwe
2013-11-21 19:16     ` Vivek Goyal
2013-11-22  1:03     ` Kees Cook
2013-11-22  2:13       ` Vivek Goyal
2013-11-22 20:42   ` Jiri Kosina
2014-01-17 19:17     ` Vivek Goyal
2013-11-29  3:10   ` Baoquan He
2013-12-02 15:27     ` WANG Chao
2013-12-02 15:44     ` Vivek Goyal
2013-12-04  1:35       ` Baoquan He
2013-12-04 17:19         ` Vivek Goyal
2013-12-04  1:56   ` Baoquan He
2013-12-04  8:19     ` Baoquan He
2013-12-04 17:32     ` Vivek Goyal [this message]
2013-11-20 17:50 ` [PATCH 5/6] kexec-bzImage: Support for loading bzImage using 64bit entry Vivek Goyal
2013-11-21 19:07   ` Greg KH
2013-11-21 19:21     ` Vivek Goyal
2013-11-22 15:24       ` H. Peter Anvin
2013-11-28 11:35   ` Baoquan He
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
2013-11-28 11:28   ` Baoquan He
2013-12-02 15:30     ` Vivek Goyal
2013-12-04  1:51       ` Baoquan He
2013-12-04 17:20         ` Vivek Goyal
2013-12-04  1:41   ` Baoquan He
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 19:07   ` Vivek Goyal
2013-11-21 19:46     ` Vivek Goyal
2013-11-21 19:06 ` Geert Uytterhoeven
2013-11-21 19:14   ` Vivek Goyal
2013-11-21 23:07 ` Eric W. Biederman
2013-11-22  1:28   ` H. Peter Anvin
2013-11-22  2:35     ` Vivek Goyal
2013-11-22  2:40       ` H. Peter Anvin
2013-11-22  1:55   ` Vivek Goyal
2013-11-22  9:09     ` Geert Uytterhoeven
2013-11-22 13:30       ` Jiri Kosina
2013-11-22 13:46         ` Vivek Goyal
2013-11-22 13:50           ` Jiri Kosina
2013-11-22 15:33             ` Vivek Goyal
2013-11-22 17:45               ` Kees Cook
2013-11-22 13:43       ` Vivek Goyal
2013-11-22 15:25         ` Geert Uytterhoeven
2013-11-22 15:33           ` Jiri Kosina
2013-11-22 15:57             ` Eric Paris
2013-11-22 16:04               ` Jiri Kosina
2013-11-22 16:08                 ` Vivek Goyal
2013-11-22 13:34     ` Eric W. Biederman
2013-11-22 14:19       ` Vivek Goyal
2013-11-22 19:48         ` Greg KH
2013-11-23  3:23         ` Eric W. Biederman
2013-12-04 19:34           ` Vivek Goyal
2013-12-05  4:10             ` Eric W. Biederman
2013-11-25 10:04       ` Michael Holzheu
2013-11-25 15:36         ` Vivek Goyal
2013-11-25 16:15           ` Michael Holzheu
2013-11-22  0:55 ` HATAYAMA Daisuke
2013-11-22  2:03   ` Vivek Goyal
2013-12-03 13:23 ` Baoquan He

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