From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v26 0/7] arm64: add kdump support
Date: Tue, 4 Oct 2016 11:18:33 +0100 [thread overview]
Message-ID: <20161004101833.GB18083@leverpostej> (raw)
In-Reply-To: <1ae717d6-b2aa-105b-4f47-d879882ca5d3@caviumnetworks.com>
On Mon, Oct 03, 2016 at 06:11:40PM +0530, Manish Jaggi wrote:
> On 10/03/2016 04:34 PM, AKASHI Takahiro wrote:
> > On Mon, Oct 03, 2016 at 01:24:34PM +0530, Manish Jaggi wrote:
> >> Observations:
> >> 1.1. Dump capture kernel shows different memory map.
> >> ---------------------------------------------------
> >> In dump capture kernel /proc/meminfo and /proc/iomem differ
> >>
> >> root at arm64:/home/ubuntu/CODE/crash#
> >> MemTotal: 65882432 kB
> >> MemFree: 65507136 kB
> >> MemAvailable: 60373632 kB
> >> Buffers: 29248 kB
> >> Cached: 46720 kB
> >> SwapCached: 0 kB
> >> Active: 63872 kB
> >> Inactive: 19776 kB
> >> Active(anon): 8256 kB
> >> Inactive(anon): 7616 kB
> >>
> >> First kernel is booted with mem=2G crashkernel=1G command line option.
> >> While the system has 64G memory.
> >>
> >> root at arm64:/home/ubuntu/CODE/crash# cat /proc/iomem
> >> 41400000-fffeffff : System RAM
> >> 41480000-420cffff : Kernel code
> >> 42490000-4278ffff : Kernel data
> >> ffff0000-ffffffff : reserved
> >> 100000000-ffaa7ffff : System RAM
> >> ffaa80000-ffaabffff : reserved
> >> ffaac0000-fffa6ffff : System RAM
> >> fffa70000-fffacffff : reserved
> >> fffad0000-fffffffff : System RAM
> >
> > Are you saying that "mem=..." doesn't have any effect?
> What I am saying it that If the first kernel is booted using mem= option and crashkernel= option
> the memory for second kernel has to be withing the crashkernel size.
Please don't try to use mem= to limit the kernel to a specific range of
memory. It's really only there as a tool to test handling of low-memory
situations.
While it guarantees that at most, the amount requested will be used
(modulo a number of edge cases with reserved memory ranges), it does not
guarantee *which* memory will be used. It is *very* fragile.
Thanks,
Mark.
next prev parent reply other threads:[~2016-10-04 10:18 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-07 4:29 [PATCH v26 0/7] arm64: add kdump support AKASHI Takahiro
2016-09-07 4:29 ` [PATCH v26 1/7] arm64: kdump: reserve memory for crash dump kernel AKASHI Takahiro
2016-09-22 10:23 ` Matthias Bruger
2016-09-23 8:37 ` AKASHI Takahiro
2016-09-07 4:29 ` [PATCH v26 2/7] arm64: kdump: implement machine_crash_shutdown() AKASHI Takahiro
2016-09-14 18:09 ` James Morse
2016-09-15 8:13 ` Marc Zyngier
2016-09-16 3:21 ` AKASHI Takahiro
2016-09-16 14:49 ` James Morse
2016-09-20 7:36 ` AKASHI Takahiro
2016-09-07 4:29 ` [PATCH v26 3/7] arm64: kdump: add kdump support AKASHI Takahiro
2016-09-16 14:50 ` James Morse
2016-09-20 7:46 ` AKASHI Takahiro
2016-09-22 15:50 ` Matthias Brugger
2016-09-07 4:29 ` [PATCH v26 4/7] arm64: kdump: add VMCOREINFO's for user-space coredump tools AKASHI Takahiro
2016-09-16 16:04 ` James Morse
2016-09-07 4:29 ` [PATCH v26 5/7] arm64: kdump: enable kdump in the arm64 defconfig AKASHI Takahiro
2016-09-07 4:29 ` [PATCH v26 6/7] arm64: kdump: update a kernel doc AKASHI Takahiro
2016-09-16 16:08 ` James Morse
2016-09-20 8:27 ` AKASHI Takahiro
2016-09-26 17:21 ` Matthias Brugger
2016-09-07 4:32 ` [PATCH v26 7/7] Documentation: dt: chosen properties for arm64 kdump AKASHI Takahiro
2016-09-16 13:03 ` Rob Herring
2016-09-07 4:37 ` [PATCH v26 0/7] arm64: add kdump support AKASHI Takahiro
2016-09-16 16:04 ` James Morse
2016-09-16 20:17 ` Ard Biesheuvel
2016-09-19 16:05 ` James Morse
2016-09-19 16:10 ` Ard Biesheuvel
2016-09-21 7:42 ` AKASHI Takahiro
2016-09-21 7:33 ` AKASHI Takahiro
2016-10-03 7:54 ` Manish Jaggi
2016-10-03 11:04 ` AKASHI Takahiro
2016-10-03 12:41 ` Manish Jaggi
2016-10-04 2:56 ` AKASHI Takahiro
2016-10-04 9:46 ` James Morse
2016-10-04 10:05 ` Manish Jaggi
2016-10-04 10:53 ` James Morse
2016-10-04 13:23 ` Manish Jaggi
2016-10-05 5:48 ` AKASHI Takahiro
2016-10-05 5:41 ` AKASHI Takahiro
2016-10-04 10:18 ` Mark Rutland [this message]
2016-10-17 15:41 ` Ruslan Bilovol
2016-10-18 6:26 ` AKASHI Takahiro
2016-11-01 12:19 ` Ruslan Bilovol
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