linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: David Hildenbrand <david@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	andreyknvl@google.com, bhe@redhat.com,
	christian.brauner@ubuntu.com, colin.king@canonical.com,
	corbet@lwn.net, dyoung@redhat.com, frederic@kernel.org,
	gpiccoli@canonical.com, john.p.donnelly@oracle.com,
	jpoimboe@redhat.com, keescook@chromium.org, linux-mm@kvack.org,
	masahiroy@kernel.org, mchehab+huawei@kernel.org,
	mike.kravetz@oracle.com, mingo@kernel.org,
	mm-commits@vger.kernel.org, paulmck@kernel.org,
	peterz@infradead.org, rdunlap@infradead.org, rostedt@goodmis.org,
	rppt@kernel.org, saeed.mirzamohammadi@oracle.com,
	samitolvanen@google.com, sboyd@kernel.org, tglx@linutronix.de,
	torvalds@linux-foundation.org, vgoyal@redhat.com,
	yifeifz2@illinois.edu
Subject: Re: [patch 48/91] kernel/crash_core: add crashkernel=auto for vmcore creation
Date: Fri, 7 May 2021 10:16:10 +0200	[thread overview]
Message-ID: <889c6b90-7335-71ce-c955-3596e6ac7c5a@redhat.com> (raw)
In-Reply-To: <20210507010432.IN24PudKT%akpm@linux-foundation.org>

On 07.05.21 03:04, Andrew Morton wrote:
> From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
> Subject: kernel/crash_core: add crashkernel=auto for vmcore creation
> 
> This adds crashkernel=auto feature to configure reserved memory for vmcore
> creation.  CONFIG_CRASH_AUTO_STR is defined to be set for different kernel
> distributions and different archs based on their needs.
> 
> Link: https://lkml.kernel.org/r/20210223174153.72802-1-saeed.mirzamohammadi@oracle.com
> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
> Tested-by: John Donnelly <john.p.donnelly@oracle.com>
> ed-by: Dave Young <dyoung@redhat.com>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: "Paul E. McKenney" <paulmck@kernel.org>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> Cc: Mike Kravetz <mike.kravetz@oracle.com>
> Cc: "Guilherme G. Piccoli" <gpiccoli@canonical.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> Cc: YiFei Zhu <yifeifz2@illinois.edu>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Cc: Sami Tolvanen <samitolvanen@google.com>
> Cc: Frederic Weisbecker <frederic@kernel.org>
> Cc: Christian Brauner <christian.brauner@ubuntu.com>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: Andrey Konovalov <andreyknvl@google.com>
> Cc: Colin Ian King <colin.king@canonical.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>   Documentation/admin-guide/kdump/kdump.rst       |    3 +-
>   Documentation/admin-guide/kernel-parameters.txt |    6 ++++
>   arch/Kconfig                                    |   20 ++++++++++++++
>   kernel/crash_core.c                             |    7 ++++
>   4 files changed, 35 insertions(+), 1 deletion(-)
> 
> --- a/arch/Kconfig~kernel-crash_core-add-crashkernel=auto-for-vmcore-creation
> +++ a/arch/Kconfig
> @@ -14,6 +14,26 @@ menu "General architecture-dependent opt
>   config CRASH_CORE
>   	bool
>   
> +config CRASH_AUTO_STR
> +	string "Memory reserved for crash kernel"
> +	depends on CRASH_CORE
> +	default "1G-64G:128M,64G-1T:256M,1T-:512M"
> +	help
> +	  This configures the reserved memory dependent
> +	  on the value of System RAM. The syntax is:
> +	  crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> +	              range=start-[end]
> +
> +	  For example:
> +	      crashkernel=512M-2G:64M,2G-:128M
> +
> +	  This would mean:
> +
> +	      1) if the RAM is smaller than 512M, then don't reserve anything
> +	         (this is the "rescue" case)
> +	      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
> +	      3) if the RAM size is larger than 2G, then reserve 128M
> +
>   config KEXEC_CORE
>   	select CRASH_CORE
>   	bool
> --- a/Documentation/admin-guide/kdump/kdump.rst~kernel-crash_core-add-crashkernel=auto-for-vmcore-creation
> +++ a/Documentation/admin-guide/kdump/kdump.rst
> @@ -285,7 +285,8 @@ This would mean:
>       2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>       3) if the RAM size is larger than 2G, then reserve 128M
>   
> -
> +Or you can use crashkernel=auto to choose the crash kernel memory size
> +based on the recommended configuration set for each arch.
>   
>   Boot into System Kernel
>   =======================
> --- a/Documentation/admin-guide/kernel-parameters.txt~kernel-crash_core-add-crashkernel=auto-for-vmcore-creation
> +++ a/Documentation/admin-guide/kernel-parameters.txt
> @@ -751,6 +751,12 @@
>   			a memory unit (amount[KMG]). See also
>   			Documentation/admin-guide/kdump/kdump.rst for an example.
>   
> +	crashkernel=auto
> +			[KNL] This parameter will set the reserved memory for
> +			the crash kernel based on the value of the CRASH_AUTO_STR
> +			that is the best effort estimation for each arch. See also
> +			arch/Kconfig for further details.
> +
>   	crashkernel=size[KMG],high
>   			[KNL, X86-64] range could be above 4G. Allow kernel
>   			to allocate physical memory region from top, so could
> --- a/kernel/crash_core.c~kernel-crash_core-add-crashkernel=auto-for-vmcore-creation
> +++ a/kernel/crash_core.c
> @@ -7,6 +7,7 @@
>   #include <linux/crash_core.h>
>   #include <linux/utsname.h>
>   #include <linux/vmalloc.h>
> +#include <linux/kexec.h>
>   
>   #include <asm/page.h>
>   #include <asm/sections.h>
> @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(ch
>   	if (suffix)
>   		return parse_crashkernel_suffix(ck_cmdline, crash_size,
>   				suffix);
> +#ifdef CONFIG_CRASH_AUTO_STR
> +	if (strncmp(ck_cmdline, "auto", 4) == 0) {
> +		ck_cmdline = CONFIG_CRASH_AUTO_STR;
> +		pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
> +	}
> +#endif
I remember that the original "crashkernel=auto" as once proposed by Red 
Hat people did not receive a warm welcome.

Let me take a look .... oh, there it is from 2009

https://marc.info/?t=125006512600002&r=1&w=2

and then we had it in 2018

https://lkml.org/lkml/2018/5/20/262


The issue I have with this: it's just plain wrong when you take memory 
hotplug into serious account as we see it quite heavily in VMs. You 
don't know what you'll need when building a kernel. Just pass it via the 
cmdline ...

-- 
Thanks,

David / dhildenb



  parent reply	other threads:[~2021-05-07  8:16 UTC|newest]

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-07  1:01 incoming Andrew Morton
2021-05-07  1:02 ` [patch 01/91] alpha: eliminate old-style function definitions Andrew Morton
2021-05-07  1:02 ` [patch 02/91] alpha: csum_partial_copy.c: add function prototypes from <net/checksum.h> Andrew Morton
2021-05-07  1:02 ` [patch 03/91] fs/proc/generic.c: fix incorrect pde_is_permanent check Andrew Morton
2021-05-07  1:02 ` [patch 04/91] proc: save LOC in __xlate_proc_name() Andrew Morton
2021-05-07  2:24   ` Linus Torvalds
2021-05-07  1:02 ` [patch 05/91] proc: mandate ->proc_lseek in "struct proc_ops" Andrew Morton
2021-05-07  1:02 ` [patch 06/91] proc: delete redundant subset=pid check Andrew Morton
2021-05-07  1:02 ` [patch 07/91] selftests: proc: test subset=pid Andrew Morton
2021-05-07  1:02 ` [patch 08/91] proc/sysctl: fix function name error in comments Andrew Morton
2021-05-07  1:02 ` [patch 09/91] include: remove pagemap.h from blkdev.h Andrew Morton
2021-05-07  1:02 ` [patch 10/91] kernel.h: drop inclusion in bitmap.h Andrew Morton
2021-05-07  1:02 ` [patch 11/91] linux/profile.h: remove unnecessary declaration Andrew Morton
2021-05-07  1:02 ` [patch 12/91] kernel/async.c: fix pr_debug statement Andrew Morton
2021-05-07  1:02 ` [patch 13/91] kernel/cred.c: make init_groups static Andrew Morton
2021-05-07  1:02 ` [patch 14/91] tools: disable -Wno-type-limits Andrew Morton
2021-05-07  1:02 ` [patch 15/91] tools: bitmap: sync function declarations with the kernel Andrew Morton
2021-05-07  1:02 ` [patch 16/91] tools: sync BITMAP_LAST_WORD_MASK() macro " Andrew Morton
2021-05-07  1:02 ` [patch 17/91] arch: rearrange headers inclusion order in asm/bitops for m68k, sh and h8300 Andrew Morton
2021-05-07  1:02 ` [patch 18/91] lib: extend the scope of small_const_nbits() macro Andrew Morton
2021-05-07  1:03 ` [patch 19/91] tools: sync small_const_nbits() macro with the kernel Andrew Morton
2021-05-07  1:03 ` [patch 20/91] lib: inline _find_next_bit() wrappers Andrew Morton
2021-05-07  1:03 ` [patch 21/91] tools: sync find_next_bit implementation Andrew Morton
2021-05-07  1:03 ` [patch 22/91] lib: add fast path for find_next_*_bit() Andrew Morton
2021-05-07  1:03 ` [patch 23/91] lib: add fast path for find_first_*_bit() and find_last_bit() Andrew Morton
2021-05-07  1:03 ` [patch 24/91] tools: sync lib/find_bit implementation Andrew Morton
2021-05-07  1:03 ` [patch 25/91] MAINTAINERS: add entry for the bitmap API Andrew Morton
2021-05-07  1:03 ` [patch 26/91] lib/bch.c: fix a typo in the file bch.c Andrew Morton
2021-05-07  1:03 ` [patch 27/91] lib: fix inconsistent indenting in process_bit1() Andrew Morton
2021-05-07  1:03 ` [patch 28/91] lib/list_sort.c: fix typo in function description Andrew Morton
2021-05-07  1:03 ` [patch 29/91] lib/genalloc.c: fix a typo Andrew Morton
2021-05-07  1:03 ` [patch 30/91] lib: crc8: pointer to data block should be const Andrew Morton
2021-05-07  1:03 ` [patch 31/91] lib: stackdepot: turn depot_lock spinlock to raw_spinlock Andrew Morton
2021-05-07  1:03 ` [patch 32/91] lib/percpu_counter: tame kernel-doc compile warning Andrew Morton
2021-05-07  1:03 ` [patch 33/91] lib/genalloc: add parameter description to fix doc " Andrew Morton
2021-05-07  1:03 ` [patch 34/91] lib: parser: clean up kernel-doc Andrew Morton
2021-05-07  1:03 ` [patch 35/91] include/linux/compat.h: remove unneeded declaration from COMPAT_SYSCALL_DEFINEx() Andrew Morton
2021-05-07  1:03 ` [patch 36/91] checkpatch: warn when missing newline in return sysfs_emit() formats Andrew Morton
2021-05-07  1:03 ` [patch 37/91] checkpatch: exclude four preprocessor sub-expressions from MACRO_ARG_REUSE Andrew Morton
2021-05-07  1:04 ` [patch 38/91] checkpatch: improve ALLOC_ARRAY_ARGS test Andrew Morton
2021-05-07  1:04 ` [patch 39/91] kselftest: introduce new epoll test case Andrew Morton
2021-05-07  1:04 ` [patch 40/91] fs/epoll: restore waking from ep_done_scan() Andrew Morton
2021-05-07  1:04 ` [patch 41/91] isofs: fix fall-through warnings for Clang Andrew Morton
2021-05-07  1:04 ` [patch 42/91] fs/nilfs2: fix misspellings using codespell tool Andrew Morton
2021-05-07  1:04 ` [patch 43/91] nilfs2: fix typos in comments Andrew Morton
2021-05-07  1:04 ` [patch 44/91] hpfs: replace one-element array with flexible-array member Andrew Morton
2021-05-07  1:04 ` [patch 45/91] do_wait: make PIDTYPE_PID case O(1) instead of O(n) Andrew Morton
2021-05-07  1:04 ` [patch 46/91] kernel/fork.c: simplify copy_mm() Andrew Morton
2021-05-07  1:04 ` [patch 47/91] kernel/fork.c: fix typos Andrew Morton
2021-05-07  1:04 ` [patch 48/91] kernel/crash_core: add crashkernel=auto for vmcore creation Andrew Morton
2021-05-07  7:25   ` Linus Torvalds
2021-05-08  3:13     ` Baoquan He
2021-05-08  3:29       ` Baoquan He
2021-05-07  8:16   ` David Hildenbrand [this message]
2021-05-08  8:51     ` Baoquan He
2021-05-08  9:22       ` David Hildenbrand
2021-05-10  4:53         ` Baoquan He
2021-05-10  8:32           ` David Hildenbrand
2021-05-10 10:43             ` Baoquan He
2021-05-10 11:01               ` David Hildenbrand
2021-05-10 11:44                 ` Dave Young
2021-05-10 11:56                   ` David Hildenbrand
2021-05-11 13:36                     ` Baoquan He
2021-05-11 16:31                       ` Mike Rapoport
2021-05-11 17:07                         ` David Hildenbrand
2021-05-12 14:51                           ` Baoquan He
2021-05-12 15:07                             ` David Hildenbrand
2021-05-13  5:04                               ` Baoquan He
2021-05-12 19:03                             ` Kairui Song
2021-05-17  8:22                             ` David Hildenbrand
2021-05-18  8:49                               ` Baoquan He
2021-05-18  8:51                                 ` David Hildenbrand
2021-05-18  9:24                                   ` Dave Young
2021-05-12 14:13                         ` Baoquan He
2021-05-12  7:42                     ` Dave Young
2021-05-07  1:04 ` [patch 49/91] kexec: add kexec reboot string Andrew Morton
2021-05-07  1:04 ` [patch 50/91] kernel: kexec_file: fix error return code of kexec_calculate_store_digests() Andrew Morton
2021-05-07  1:04 ` [patch 51/91] kexec: dump kmessage before machine_kexec Andrew Morton
2021-05-07  1:04 ` [patch 52/91] gcov: combine common code Andrew Morton
2021-05-07  1:04 ` [patch 53/91] gcov: simplify buffer allocation Andrew Morton
2021-05-07  1:04 ` [patch 54/91] gcov: use kvmalloc() Andrew Morton
2021-05-07  1:04 ` [patch 55/91] gcov: clang: drop support for clang-10 and older Andrew Morton
2021-05-07  1:04 ` [patch 56/91] smp: kernel/panic.c - silence warnings Andrew Morton
2021-05-07  1:05 ` [patch 57/91] delayacct: clear right task's flag after blkio completes Andrew Morton
2021-05-07  1:05 ` [patch 58/91] gdb: lx-symbols: store the abspath() Andrew Morton
2021-05-07  1:05 ` [patch 59/91] scripts/gdb: document lx_current is only supported by x86 Andrew Morton
2021-05-07  1:05 ` [patch 60/91] scripts/gdb: add lx_current support for arm64 Andrew Morton
2021-05-07  1:05 ` [patch 61/91] kernel/resource: make walk_system_ram_res() find all busy IORESOURCE_SYSTEM_RAM resources Andrew Morton
2021-05-07  1:05 ` [patch 62/91] kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources Andrew Morton
2021-05-07  1:05 ` [patch 63/91] kernel/resource: remove first_lvl / siblings_only logic Andrew Morton
2021-05-07  1:05 ` [patch 64/91] kernel/resource: allow region_intersects users to hold resource_lock Andrew Morton
2021-05-07  1:05 ` [patch 65/91] kernel/resource: refactor __request_region to allow external locking Andrew Morton
2021-05-07  1:05 ` [patch 66/91] kernel/resource: fix locking in request_free_mem_region Andrew Morton
2021-05-07  1:05 ` [patch 67/91] selftests: remove duplicate include Andrew Morton
2021-05-07  1:05 ` [patch 68/91] kernel/async.c: stop guarding pr_debug() statements Andrew Morton
2021-05-07  1:05 ` [patch 69/91] kernel/async.c: remove async_unregister_domain() Andrew Morton
2021-05-07  1:05 ` [patch 70/91] init/initramfs.c: do unpacking asynchronously Andrew Morton
2021-05-07  1:05 ` [patch 71/91] modules: add CONFIG_MODPROBE_PATH Andrew Morton
2021-05-07  1:05 ` [patch 72/91] ipc/sem.c: mundane typo fixes Andrew Morton
2021-05-07  1:05 ` [patch 73/91] mm: fix some typos and code style problems Andrew Morton
2021-05-07  1:05 ` [patch 74/91] drivers/char: remove /dev/kmem for good Andrew Morton
2021-05-07  1:06 ` [patch 75/91] mm: remove xlate_dev_kmem_ptr() Andrew Morton
2021-05-07  1:06 ` [patch 76/91] mm/vmalloc: remove vwrite() Andrew Morton
2021-05-07  1:06 ` [patch 77/91] arm: print alloc free paths for address in registers Andrew Morton
2021-05-07  1:06 ` [patch 78/91] scripts/spelling.txt: add "overlfow" Andrew Morton
2021-05-07  1:06 ` [patch 79/91] scripts/spelling.txt: add "diabled" typo Andrew Morton
2021-05-07  1:06 ` [patch 80/91] scripts/spelling.txt: add "overflw" Andrew Morton
2021-05-07  1:06 ` [patch 81/91] mm/slab.c: fix spelling mistake "disired" -> "desired" Andrew Morton
2021-05-07  1:06 ` [patch 82/91] include/linux/pgtable.h: few spelling fixes Andrew Morton
2021-05-07  1:06 ` [patch 83/91] kernel/umh.c: fix some spelling mistakes Andrew Morton
2021-05-07  1:06 ` [patch 84/91] kernel/user_namespace.c: fix typos Andrew Morton
2021-05-07  1:06 ` [patch 85/91] kernel/up.c: fix typo Andrew Morton
2021-05-07  1:06 ` [patch 86/91] kernel/sys.c: " Andrew Morton
2021-05-07  1:06 ` [patch 87/91] fs: fat: fix spelling typo of values Andrew Morton
2021-05-07  1:06 ` [patch 88/91] ipc/sem.c: spelling fix Andrew Morton
2021-05-07  1:06 ` [patch 89/91] treewide: remove editor modelines and cruft Andrew Morton
2021-05-07  1:06 ` [patch 90/91] mm: fix typos in comments Andrew Morton
2021-05-07  1:06 ` [patch 91/91] " Andrew Morton
2021-05-07  7:12 ` incoming Linus Torvalds

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=889c6b90-7335-71ce-c955-3596e6ac7c5a@redhat.com \
    --to=david@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=andreyknvl@google.com \
    --cc=bhe@redhat.com \
    --cc=christian.brauner@ubuntu.com \
    --cc=colin.king@canonical.com \
    --cc=corbet@lwn.net \
    --cc=dyoung@redhat.com \
    --cc=frederic@kernel.org \
    --cc=gpiccoli@canonical.com \
    --cc=john.p.donnelly@oracle.com \
    --cc=jpoimboe@redhat.com \
    --cc=keescook@chromium.org \
    --cc=linux-mm@kvack.org \
    --cc=masahiroy@kernel.org \
    --cc=mchehab+huawei@kernel.org \
    --cc=mike.kravetz@oracle.com \
    --cc=mingo@kernel.org \
    --cc=mm-commits@vger.kernel.org \
    --cc=paulmck@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rdunlap@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=rppt@kernel.org \
    --cc=saeed.mirzamohammadi@oracle.com \
    --cc=samitolvanen@google.com \
    --cc=sboyd@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=vgoyal@redhat.com \
    --cc=yifeifz2@illinois.edu \
    --subject='Re: [patch 48/91] kernel/crash_core: add crashkernel=auto for vmcore creation' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).