From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wm1-x329.google.com ([2a00:1450:4864:20::329]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lUsVZ-004bQK-QE for kexec@lists.infradead.org; Fri, 09 Apr 2021 14:53:19 +0000 Received: by mail-wm1-x329.google.com with SMTP id g66-20020a1c39450000b0290125d187ba22so2596498wma.2 for ; Fri, 09 Apr 2021 07:53:16 -0700 (PDT) Date: Fri, 9 Apr 2021 16:53:13 +0200 From: Corentin Labbe Subject: Re: crashkernel reservation failed - No suitable area found on a cortina/gemini SoC Message-ID: References: <34ff1fcc-e9ee-02c2-b2a8-d98a24ce94c3@linux.vnet.ibm.com> <7a75028b-4495-cd51-6a32-59fcf6e0f166@linux.vnet.ibm.com> <291254c6-97e3-f5ba-dcee-77f8e4d25f9b@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <291254c6-97e3-f5ba-dcee-77f8e4d25f9b@linux.vnet.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Bruce Mitchell Cc: ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Le Wed, Apr 07, 2021 at 07:59:27AM -0700, Bruce Mitchell a =E9crit : > On 4/7/2021 07:48, Corentin Labbe wrote: > > Le Wed, Apr 07, 2021 at 07:28:26AM -0700, Bruce Mitchell a =E9crit : > >> On 4/7/2021 07:23, Corentin Labbe wrote: > >>> Le Wed, Apr 07, 2021 at 07:13:04AM -0700, Bruce Mitchell a =E9crit : > >>>> On 4/7/2021 05:54, Corentin Labbe wrote: > >>>>> Hello > >>>>> > >>>>> I try to do kexec on a cortina/gemini SoC. > >>>>> On a "normal" boot, kexec fail to find memory so I added crashkerne= l=3D8M to cmdline. (kernel size is ~6M). > >>>>> But now, kernel fail to reserve memory: > >>>>> Load Kern image from 0x30020000 to 0x800000 size 7340032 > >>>>> Booting Linux on physical CPU 0x0 > >>>>> Linux version 5.12.0-rc5-next-20210401+ (compile@Red) (armv7a-unkno= wn-linux-gnueabihf-gcc (Gentoo 9.3.0-r2 p4) 9.3.0, GNU ld (Gentoo 2.34 p6) = 2.34.0) #98 PREEMPT Wed Apr 7 14:14:08 CEST 2021 > >>>>> CPU: FA526 [66015261] revision 1 (ARMv4), cr=3D0000397f > >>>>> CPU: VIVT data cache, VIVT instruction cache > >>>>> OF: fdt: Machine model: Edimax NS-2502 > >>>>> Memory policy: Data cache writeback > >>>>> Zone ranges: > >>>>> Normal [mem 0x0000000000000000-0x0000000007ffffff] > >>>>> HighMem empty > >>>>> Movable zone start for each node > >>>>> Early memory node ranges > >>>>> node 0: [mem 0x0000000000000000-0x0000000007ffffff] > >>>>> Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff] > >>>>> crashkernel reservation failed - No suitable area found. > >>>>> Built 1 zonelists, mobility grouping on. Total pages: 32512 > >>>>> Kernel command line: console=3DttyS0,19200n8 ip=3Ddhcp crashkernel= =3D8M > >>>>> Dentry cache hash table entries: 16384 (order: 4, 65536 bytes, line= ar) > >>>>> Inode-cache hash table entries: 8192 (order: 3, 32768 bytes, linear) > >>>>> mem auto-init: stack:off, heap alloc:off, heap free:off > >>>>> Memory: 119476K/131072K available (5034K kernel code, 579K rwdata, = 1372K rodata, 3020K init, 210K bss, 11596K reserved, 0K cma-reserved, 0K hi= ghmem) > >>>>> SLUB: HWalign=3D32, Order=3D0-3, MinObjects=3D0, CPUs=3D1, Nodes=3D1 > >>>>> > >>>>> What can I do ? > >>>>> > >>>>> Thanks > >>>>> Regards > >>>>> > >>>>> _______________________________________________ > >>>>> kexec mailing list > >>>>> kexec@lists.infradead.org > >>>>> http://lists.infradead.org/mailman/listinfo/kexec > >>>>> > >>>> > >>>> Hello Corentin, > >>>> > >>>> I see much larger crashkernel=3DxxM being shown here > >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/t= ree/Documentation/admin-guide/kdump/kdump.rst > >>>> and from many of my other searches. > >>>> > >>>> Here is an interesting article on kdump for ARM-32 > >>>> https://kaiwantech.wordpress.com/2017/07/13/setting-up-kdump-and-cra= sh-for-arm-32-an-ongoing-saga/ > >>>> > >>>> > >>>> Here is the kernel command line reference > >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/t= ree/Documentation/admin-guide/kernel-parameters.txt?h=3Dv5.11#n732 > >>>> > >>>> I feel your frustrations too. > >>> > >>> Hello > >>> > >>> Thanks but I have already read those documentation. > >>> I search to know why the kernel cannot find 8M of memory ouf of 128. > >>> > >>> Regards > >>> > >> > >> How much more memory does the kernel and initrd above and beyond just > >> their physical size? (heaps, stacks, buffers, virtual filesystems) > > = > > The kernel size include a rootfs.cpio.lzma of 3MB and dtb is appended. > > The total kernel size is 7MB. > > The uncompressed size of the kernel is 13M (size of vmlinux) > > The uncompressed size of rootfs is 11M. > > = > > cat /proc/meminfo > > MemTotal: 122496 kB > > MemFree: 103700 kB > > MemAvailable: 101936 kB > > Buffers: 0 kB > > Cached: 10904 kB > > SwapCached: 0 kB > > Active: 4304 kB > > Inactive: 8012 kB > > Active(anon): 4304 kB > > Inactive(anon): 8012 kB > > Active(file): 0 kB > > Inactive(file): 0 kB > > Unevictable: 0 kB > > Mlocked: 0 kB > > HighTotal: 0 kB > > HighFree: 0 kB > > LowTotal: 122496 kB > > LowFree: 103700 kB > > SwapTotal: 0 kB > > SwapFree: 0 kB > > Dirty: 0 kB > > Writeback: 0 kB > > AnonPages: 1428 kB > > Mapped: 3552 kB > > Shmem: 10904 kB > > KReclaimable: 608 kB > > Slab: 2960 kB > > SReclaimable: 608 kB > > SUnreclaim: 2352 kB > > KernelStack: 312 kB > > PageTables: 136 kB > > NFS_Unstable: 0 kB > > Bounce: 0 kB > > WritebackTmp: 0 kB > > CommitLimit: 61248 kB > > Committed_AS: 14336 kB > > VmallocTotal: 901120 kB > > VmallocUsed: 64 kB > > VmallocChunk: 0 kB > > Percpu: 32 kB > > CmaTotal: 0 kB > > CmaFree: 0 kB > > = > = > I believe you need space for all of that, > the smallest that would work for me was 20MB. I tried without any change. Anyway when trying to kexec I got: kexec --no-ifdown --command-line=3D"console=3DttyS0,19200n8" /tmp/kernel = | Could not find a free area of memory of 0x668a8a bytes... Cannot load /tmp/kernel So reserving 8M is enough according to what kexec said. So anyone know why the kernel cannot reserve 8M ? Thanks _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec