linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, anderson@redhat.com,
	benh@kernel.crashing.org, bhe@redhat.com,
	bhupesh.sharma@linaro.org, bp@alien8.de, catalin.marinas@arm.com,
	dyoung@redhat.com, james.morse@arm.com, k-hagio@ab.jp.nec.com,
	kernelfans@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com,
	mingo@kernel.org, mm-commits@vger.kernel.org, mpe@ellerman.id.au,
	paulus@samba.org, stable@vger.kernel.org, tglx@linutronix.de,
	torvalds@linux-foundation.org, will@kernel.org
Subject: [patch 08/18] crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo
Date: Tue, 15 Jun 2021 18:23:36 -0700	[thread overview]
Message-ID: <20210616012336.mnhwEhLlA%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210615182248.9a0ba90e8e66b9f4a53c0d23@linux-foundation.org>

From: Pingfan Liu <kernelfans@gmail.com>
Subject: crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo

As mentioned in kernel commit 1d50e5d0c505 ("crash_core, vmcoreinfo:
Append 'MAX_PHYSMEM_BITS' to vmcoreinfo"), SECTION_SIZE_BITS in the
formula:

    #define SECTIONS_SHIFT    (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)

Besides SECTIONS_SHIFT, SECTION_SIZE_BITS is also used to calculate
PAGES_PER_SECTION in makedumpfile just like kernel.

Unfortunately, this arch-dependent macro SECTION_SIZE_BITS changes, e.g. 
recently in kernel commit f0b13ee23241 ("arm64/sparsemem: reduce
SECTION_SIZE_BITS").  But user space wants a stable interface to get this
info.  Such info is impossible to be deduced from a crashdump vmcore. 
Hence append SECTION_SIZE_BITS to vmcoreinfo.

Link: https://lkml.kernel.org/r/20210608103359.84907-1-kernelfans@gmail.com
Link: http://lists.infradead.org/pipermail/kexec/2021-June/022676.html
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Boris Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Anderson <anderson@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/crash_core.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/crash_core.c~crash_core-vmcoreinfo-append-section_size_bits-to-vmcoreinfo
+++ a/kernel/crash_core.c
@@ -464,6 +464,7 @@ static int __init crash_save_vmcoreinfo_
 	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 	VMCOREINFO_STRUCT_SIZE(mem_section);
 	VMCOREINFO_OFFSET(mem_section, section_mem_map);
+	VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
 	VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 #endif
 	VMCOREINFO_STRUCT_SIZE(page);
_


  parent reply	other threads:[~2021-06-16  1:23 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-16  1:22 incoming Andrew Morton
2021-06-16  1:23 ` [patch 01/18] mm,hwpoison: fix race with hugetlb page allocation Andrew Morton
2021-06-16  1:23 ` [patch 02/18] mm/swap: fix pte_same_as_swp() not removing uffd-wp bit when compare Andrew Morton
2021-06-16  1:23 ` [patch 03/18] mm/slub: clarify verification reporting Andrew Morton
2021-06-16  1:23 ` [patch 04/18] mm/slub: fix redzoning for small allocations Andrew Morton
2021-06-16  1:23 ` [patch 05/18] mm/slub: actually fix freelist pointer vs redzoning Andrew Morton
2021-06-16  1:23 ` [patch 06/18] mm/hugetlb: expand restore_reserve_on_error functionality Andrew Morton
2021-06-16  1:23 ` [patch 07/18] mm/memory-failure: make sure wait for page writeback in memory_failure Andrew Morton
2021-06-16  1:23 ` Andrew Morton [this message]
2021-06-16  1:23 ` [patch 09/18] mm/slub.c: include swab.h Andrew Morton
2021-06-16  1:23 ` [patch 10/18] mm, thp: use head page in __migration_entry_wait() Andrew Morton
2021-06-16  1:23 ` [patch 11/18] mm/thp: fix __split_huge_pmd_locked() on shmem migration entry Andrew Morton
2021-06-16  1:23 ` [patch 12/18] mm/thp: make is_huge_zero_pmd() safe and quicker Andrew Morton
2021-06-16  1:23 ` [patch 13/18] mm/thp: try_to_unmap() use TTU_SYNC for safe splitting Andrew Morton
2021-06-16  1:23 ` [patch 14/18] mm/thp: fix vma_address() if virtual address below file offset Andrew Morton
2021-06-16  1:24 ` [patch 15/18] mm/thp: fix page_address_in_vma() on file THP tails Andrew Morton
2021-06-16  1:24 ` [patch 16/18] mm/thp: unmap_mapping_page() to fix THP truncate_cleanup_page() Andrew Morton
2021-06-16  1:24 ` [patch 17/18] mm: thp: replace DEBUG_VM BUG with VM_WARN when unmap fails for split Andrew Morton
2021-06-16  1:24 ` [patch 18/18] mm/sparse: fix check_usemap_section_nr warnings Andrew Morton

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=20210616012336.mnhwEhLlA%akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=anderson@redhat.com \
    --cc=benh@kernel.crashing.org \
    --cc=bhe@redhat.com \
    --cc=bhupesh.sharma@linaro.org \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=dyoung@redhat.com \
    --cc=james.morse@arm.com \
    --cc=k-hagio@ab.jp.nec.com \
    --cc=kernelfans@gmail.com \
    --cc=linux-mm@kvack.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@kernel.org \
    --cc=mm-commits@vger.kernel.org \
    --cc=mpe@ellerman.id.au \
    --cc=paulus@samba.org \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=will@kernel.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).