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From: ebiederm@xmission.com (Eric W. Biederman)
To: Zhang Yanfei <zhangyanfei.yes@gmail.com>
Cc: "kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Simon Horman <horms@verge.net.au>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH 0/7] Remove unused /dev/oldmem interface
Date: Sat, 25 May 2013 16:25:21 -0700	[thread overview]
Message-ID: <87mwri8wwu.fsf@xmission.com> (raw)
In-Reply-To: <51A02E50.5020507@gmail.com> (Zhang Yanfei's message of "Sat, 25 May 2013 11:21:52 +0800")

Zhang Yanfei <zhangyanfei.yes@gmail.com> writes:

> /dev/oldmem provides the interface for us to access the "old memory" in
> the dump-capture kernel. Unfortunately, no one actually uses this interface.
>
> And this interface could actually cause some real problems if used on ia64
> where the cached/uncached accesses are mixed. See the discussion from
> the link: https://lkml.org/lkml/2013/4/12/386.
>
> So Eric suggested that we should remove /dev/oldmem as an unused piece of
> code.
>
> Besides, we used a global variable saved_max_pfn to let the capture kernel
> know the amount of memory that the previous kernel used. And for almost all
> architectures (except x86. In x86, saved_max_pfn is used by detect_calgary()),
> the only user of this variable is the read_oldmem interface of /dev/oldmem, so
> also remove the setting for saved_max_pfn in those architectures.

Except for the devices.txt update.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

> Zhang Yanfei (7):
>   /dev/oldmem: Remove this interface
>   Documentation/devices.txt: Remove /dev/oldmem description
>   Documentation/kdump/kdump.txt: Remove /dev/oldmem description
>   mips: Remove savemaxmem parameter setup
>   powerpc: Remove savemaxmem parameter setup
>   ia64: Remove setting for saved_max_pfn
>   s390: Remove setting for saved_max_pfn
>
>  Documentation/devices.txt        |    2 -
>  Documentation/kdump/kdump.txt    |   31 +++++--------------------
>  arch/ia64/kernel/efi.c           |    5 ----
>  arch/mips/kernel/crash_dump.c    |   10 --------
>  arch/powerpc/kernel/crash_dump.c |   10 --------
>  arch/s390/kernel/setup.c         |    4 ---
>  drivers/char/mem.c               |   47 --------------------------------------
>  7 files changed, 6 insertions(+), 103 deletions(-)

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WARNING: multiple messages have this Message-ID (diff)
From: ebiederm@xmission.com (Eric W. Biederman)
To: Zhang Yanfei <zhangyanfei.yes@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Simon Horman <horms@verge.net.au>,
	"kexec\@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/7] Remove unused /dev/oldmem interface
Date: Sat, 25 May 2013 16:25:21 -0700	[thread overview]
Message-ID: <87mwri8wwu.fsf@xmission.com> (raw)
In-Reply-To: <51A02E50.5020507@gmail.com> (Zhang Yanfei's message of "Sat, 25 May 2013 11:21:52 +0800")

Zhang Yanfei <zhangyanfei.yes@gmail.com> writes:

> /dev/oldmem provides the interface for us to access the "old memory" in
> the dump-capture kernel. Unfortunately, no one actually uses this interface.
>
> And this interface could actually cause some real problems if used on ia64
> where the cached/uncached accesses are mixed. See the discussion from
> the link: https://lkml.org/lkml/2013/4/12/386.
>
> So Eric suggested that we should remove /dev/oldmem as an unused piece of
> code.
>
> Besides, we used a global variable saved_max_pfn to let the capture kernel
> know the amount of memory that the previous kernel used. And for almost all
> architectures (except x86. In x86, saved_max_pfn is used by detect_calgary()),
> the only user of this variable is the read_oldmem interface of /dev/oldmem, so
> also remove the setting for saved_max_pfn in those architectures.

Except for the devices.txt update.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

> Zhang Yanfei (7):
>   /dev/oldmem: Remove this interface
>   Documentation/devices.txt: Remove /dev/oldmem description
>   Documentation/kdump/kdump.txt: Remove /dev/oldmem description
>   mips: Remove savemaxmem parameter setup
>   powerpc: Remove savemaxmem parameter setup
>   ia64: Remove setting for saved_max_pfn
>   s390: Remove setting for saved_max_pfn
>
>  Documentation/devices.txt        |    2 -
>  Documentation/kdump/kdump.txt    |   31 +++++--------------------
>  arch/ia64/kernel/efi.c           |    5 ----
>  arch/mips/kernel/crash_dump.c    |   10 --------
>  arch/powerpc/kernel/crash_dump.c |   10 --------
>  arch/s390/kernel/setup.c         |    4 ---
>  drivers/char/mem.c               |   47 --------------------------------------
>  7 files changed, 6 insertions(+), 103 deletions(-)

  parent reply	other threads:[~2013-05-25 23:26 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-25  3:21 [PATCH 0/7] Remove unused /dev/oldmem interface Zhang Yanfei
2013-05-25  3:21 ` Zhang Yanfei
2013-05-25  3:24 ` [PATCH 1/7] /dev/oldmem: Remove the interface Zhang Yanfei
2013-05-25  3:24   ` Zhang Yanfei
2013-05-25  3:26 ` [PATCH 2/7] Documentation/devices.txt: Remove /dev/oldmem description Zhang Yanfei
2013-05-25  3:26   ` Zhang Yanfei
2013-05-25 23:20   ` Eric W. Biederman
2013-05-25 23:20     ` Eric W. Biederman
2013-05-26  0:58     ` Zhang Yanfei
2013-05-26  0:58       ` Zhang Yanfei
2013-05-27  1:27       ` HATAYAMA Daisuke
2013-05-27  1:27         ` HATAYAMA Daisuke
2013-05-27  1:27         ` Zhang Yanfei
2013-05-27  1:27           ` Zhang Yanfei
2013-05-29 22:20           ` Andrew Morton
2013-05-29 22:20             ` Andrew Morton
2013-05-30  5:49             ` Zhang Yanfei
2013-05-30  5:49               ` Zhang Yanfei
2013-05-25  3:27 ` [PATCH 3/7] Documentation/kdump/kdump.txt: " Zhang Yanfei
2013-05-25  3:27   ` Zhang Yanfei
2013-05-25  3:29 ` [PATCH 4/7] mips: Remove savemaxmem parameter setup Zhang Yanfei
2013-05-25  3:29   ` Zhang Yanfei
2013-05-25  3:31 ` [PATCH 5/7] powerpc: " Zhang Yanfei
2013-05-25  3:31   ` Zhang Yanfei
2013-05-25  3:33 ` [PATCH 6/7] ia64: Remove setting for saved_max_pfn Zhang Yanfei
2013-05-25  3:33   ` Zhang Yanfei
2013-05-25  3:36 ` [PATCH 7/7] s390: " Zhang Yanfei
2013-05-25  3:36   ` Zhang Yanfei
2013-05-25  7:11 ` [PATCH 0/7] Remove unused /dev/oldmem interface H. Peter Anvin
2013-05-25  7:11   ` H. Peter Anvin
2013-05-25 23:25 ` Eric W. Biederman [this message]
2013-05-25 23:25   ` Eric W. Biederman
2013-05-28 14:37   ` Vivek Goyal
2013-05-28 14:37     ` Vivek Goyal
2013-05-28 15:11     ` H. Peter Anvin
2013-05-28 15:11       ` H. Peter Anvin
2013-05-29 22:11       ` Andrew Morton
2013-05-29 22:11         ` Andrew Morton
2013-05-28 19:00     ` Eric W. Biederman
2013-05-28 19:00       ` Eric W. Biederman
2013-05-29 16:10       ` Vivek Goyal
2013-05-29 16:10         ` Vivek Goyal

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