LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: David Hildenbrand <david@redhat.com>
To: Anshuman Khandual <anshuman.khandual@arm.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org,
	catalin.marinas@arm.com, will.deacon@arm.com
Cc: mhocko@suse.com, mgorman@techsingularity.net,
	james.morse@arm.com, mark.rutland@arm.com, robin.murphy@arm.com,
	cpandya@codeaurora.org, arunks@codeaurora.org,
	dan.j.williams@intel.com, osalvador@suse.de, cai@lca.pw,
	logang@deltatee.com, ira.weiny@intel.com
Subject: Re: [PATCH V3 0/4] arm64/mm: Enable memory hot remove
Date: Tue, 14 May 2019 11:10:15 +0200	[thread overview]
Message-ID: <ae99ac55-2690-b6ec-8600-26b9324b2a1a@redhat.com> (raw)
In-Reply-To: <1557824407-19092-1-git-send-email-anshuman.khandual@arm.com>

On 14.05.19 11:00, Anshuman Khandual wrote:
> This series enables memory hot remove on arm64 after fixing a memblock
> removal ordering problem in generic __remove_memory() and kernel page
> table race conditions on arm64. This is based on the following arm64
> working tree.
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
> 
> David had pointed out that the following patch is already in next/master
> (58b11e136dcc14358) and will conflict with the last patch here. Will fix
> the conflict once this series gets reviewed and agreed upon.

I should read the cover letter first, so ignore my comments :)

> 
> Author: David Hildenbrand <david@redhat.com>
> Date:   Wed Apr 10 11:02:27 2019 +1000
> 
>     mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail
> 
>     All callers of arch_remove_memory() ignore errors.  And we should really
>     try to remove any errors from the memory removal path.  No more errors are
>     reported from __remove_pages().  BUG() in s390x code in case
>     arch_remove_memory() is triggered.  We may implement that properly later.
>     WARN in case powerpc code failed to remove the section mapping, which is
>     better than ignoring the error completely right now.
> 
> Testing:
> 
> Tested memory hot remove on arm64 for 4K, 16K, 64K page config options with
> all possible CONFIG_ARM64_VA_BITS and CONFIG_PGTABLE_LEVELS combinations. But
> build tested on non arm64 platforms.
> 
> Changes in V3:
>  
> - Implemented most of the suggestions from Mark Rutland for remove_pagetable()
> - Fixed applicable PGTABLE_LEVEL wrappers around pgtable page freeing functions
> - Replaced 'direct' with 'sparse_vmap' in remove_pagetable() with inverted polarity
> - Changed pointer names ('p' at end) and removed tmp from iterations
> - Perform intermediate TLB invalidation while clearing pgtable entries
> - Dropped flush_tlb_kernel_range() in remove_pagetable()
> - Added flush_tlb_kernel_range() in remove_pte_table() instead
> - Renamed page freeing functions for pgtable page and mapped pages
> - Used page range size instead of order while freeing mapped or pgtable pages
> - Removed all PageReserved() handling while freeing mapped or pgtable pages
> - Replaced XXX_index() with XXX_offset() while walking the kernel page table
> - Used READ_ONCE() while fetching individual pgtable entries
> - Taken overall init_mm.page_table_lock instead of just while changing an entry
> - Dropped previously added [pmd|pud]_index() which are not required anymore
> 
> - Added a new patch to protect kernel page table race condtion for ptdump
> - Added a new patch from Mark Rutland to prevent huge-vmap with ptdump
> 
> Changes in V2: (https://lkml.org/lkml/2019/4/14/5)
> 
> - Added all received review and ack tags
> - Split the series from ZONE_DEVICE enablement for better review
> - Moved memblock re-order patch to the front as per Robin Murphy
> - Updated commit message on memblock re-order patch per Michal Hocko
> - Dropped [pmd|pud]_large() definitions
> - Used existing [pmd|pud]_sect() instead of earlier [pmd|pud]_large()
> - Removed __meminit and __ref tags as per Oscar Salvador
> - Dropped unnecessary 'ret' init in arch_add_memory() per Robin Murphy
> - Skipped calling into pgtable_page_dtor() for linear mapping page table
>   pages and updated all relevant functions
> 
> Changes in V1: (https://lkml.org/lkml/2019/4/3/28)
> 
> Anshuman Khandual (3):
>   mm/hotplug: Reorder arch_remove_memory() call in __remove_memory()
>   arm64/mm: Hold memory hotplug lock while walking for kernel page table dump
>   arm64/mm: Enable memory hot remove
> 
> Mark Rutland (1):
>   arm64/mm: Inhibit huge-vmap with ptdump
> 
>  arch/arm64/Kconfig             |   3 +
>  arch/arm64/mm/mmu.c            | 215 ++++++++++++++++++++++++++++++++++++++++-
>  arch/arm64/mm/ptdump_debugfs.c |   3 +
>  mm/memory_hotplug.c            |   3 +-
>  4 files changed, 217 insertions(+), 7 deletions(-)
> 


-- 

Thanks,

David / dhildenb

      parent reply	other threads:[~2019-05-14  9:10 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-14  9:00 Anshuman Khandual
2019-05-14  9:00 ` [PATCH V3 1/4] mm/hotplug: Reorder arch_remove_memory() call in __remove_memory() Anshuman Khandual
2019-05-14  9:05   ` David Hildenbrand
2019-05-14  9:00 ` [PATCH V3 2/4] arm64/mm: Hold memory hotplug lock while walking for kernel page table dump Anshuman Khandual
2019-05-14  9:16   ` David Hildenbrand
2019-05-14 15:40   ` Mark Rutland
2019-05-15  1:56     ` Anshuman Khandual
2019-05-15 16:58   ` Michal Hocko
2019-05-16 10:23     ` Mark Rutland
2019-05-16 11:05       ` Michal Hocko
2019-05-22 16:42         ` Mark Rutland
2019-05-24  6:06           ` Anshuman Khandual
2019-05-27  7:20           ` Michal Hocko
2019-05-28 14:09             ` Mark Rutland
2019-05-16 11:06       ` Anshuman Khandual
2019-05-16 11:16         ` Michal Hocko
2019-05-23  8:40           ` David Hildenbrand
2019-05-24  5:43             ` Anshuman Khandual
2019-05-14  9:00 ` [PATCH V3 3/4] arm64/mm: Inhibit huge-vmap with ptdump Anshuman Khandual
2019-05-14  9:20   ` David Hildenbrand
2019-05-16  8:38   ` Ard Biesheuvel
2019-05-14  9:00 ` [PATCH V3 4/4] arm64/mm: Enable memory hot remove Anshuman Khandual
2019-05-14  9:08   ` David Hildenbrand
2019-05-15 11:49   ` Mark Rutland
2019-05-16  5:34     ` Anshuman Khandual
2019-05-16 10:57       ` Mark Rutland
2019-05-17  3:15         ` Anshuman Khandual
2019-05-14  9:10 ` David Hildenbrand [this message]

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=ae99ac55-2690-b6ec-8600-26b9324b2a1a@redhat.com \
    --to=david@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=anshuman.khandual@arm.com \
    --cc=arunks@codeaurora.org \
    --cc=cai@lca.pw \
    --cc=catalin.marinas@arm.com \
    --cc=cpandya@codeaurora.org \
    --cc=dan.j.williams@intel.com \
    --cc=ira.weiny@intel.com \
    --cc=james.morse@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=logang@deltatee.com \
    --cc=mark.rutland@arm.com \
    --cc=mgorman@techsingularity.net \
    --cc=mhocko@suse.com \
    --cc=osalvador@suse.de \
    --cc=robin.murphy@arm.com \
    --cc=will.deacon@arm.com \
    --subject='Re: [PATCH V3 0/4] arm64/mm: Enable memory hot remove' \
    /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).