| Message ID | 1559121387-674-1-git-send-email-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64/mm: Enable memory hot remove | expand |
On Wed, 29 May 2019 14:46:24 +0530 Anshuman Khandual <anshuman.khandual@arm.com> wrote: > This series enables memory hot remove on arm64 after fixing a memblock > removal ordering problem in generic __remove_memory() and one possible > arm64 platform specific kernel page table race condition. This series > is based on latest v5.2-rc2 tag. Unfortunately this series clashes syntactically and semantically with David Hildenbrand's series "mm/memory_hotplug: Factor out memory block devicehandling". Could you and David please figure out what we should do here?
On 05/30/2019 03:36 AM, Andrew Morton wrote: > On Wed, 29 May 2019 14:46:24 +0530 Anshuman Khandual <anshuman.khandual@arm.com> wrote: > >> This series enables memory hot remove on arm64 after fixing a memblock >> removal ordering problem in generic __remove_memory() and one possible >> arm64 platform specific kernel page table race condition. This series >> is based on latest v5.2-rc2 tag. > > Unfortunately this series clashes syntactically and semantically with > David Hildenbrand's series "mm/memory_hotplug: Factor out memory block > devicehandling". Could you and David please figure out what we should > do here? > Hello Andrew, I was able to apply the above mentioned V3 series [1] from David with some changes listed below which tests positively on arm64. These changes assume that the arm64 hot-remove series (current V5) gets applied first. Changes to David's series A) Please drop (https://patchwork.kernel.org/patch/10962565/) [v3,04/11] - arch_remove_memory() is already being added through hot-remove series B) Rebase (https://patchwork.kernel.org/patch/10962575/) [v3, 06/11] - arm64 hot-remove series adds CONFIG_MEMORY_HOTREMOVE wrapper around arch_remove_memory() which can be dropped in the rebased patch C) Rebase (https://patchwork.kernel.org/patch/10962589/) [v3, 09/11] - hot-remove series moves arch_remove_memory() before memblock_[free|remove]() - So remove_memory_block_devices() should be moved before arch_remove_memory() in it's new position David, Please do let me know if the plan sounds good or you have some other suggestions. - Anshuman [1] https://patchwork.kernel.org/project/linux-mm/list/?series=123133
On 30.05.19 06:23, Anshuman Khandual wrote: > > > On 05/30/2019 03:36 AM, Andrew Morton wrote: >> On Wed, 29 May 2019 14:46:24 +0530 Anshuman Khandual <anshuman.khandual@arm.com> wrote: >> >>> This series enables memory hot remove on arm64 after fixing a memblock >>> removal ordering problem in generic __remove_memory() and one possible >>> arm64 platform specific kernel page table race condition. This series >>> is based on latest v5.2-rc2 tag. >> >> Unfortunately this series clashes syntactically and semantically with >> David Hildenbrand's series "mm/memory_hotplug: Factor out memory block >> devicehandling". Could you and David please figure out what we should >> do here? >> > > Hello Andrew, > > I was able to apply the above mentioned V3 series [1] from David with some changes > listed below which tests positively on arm64. These changes assume that the arm64 > hot-remove series (current V5) gets applied first. > > Changes to David's series > > A) Please drop (https://patchwork.kernel.org/patch/10962565/) [v3,04/11] > > - arch_remove_memory() is already being added through hot-remove series > > B) Rebase (https://patchwork.kernel.org/patch/10962575/) [v3, 06/11] > > - arm64 hot-remove series adds CONFIG_MEMORY_HOTREMOVE wrapper around > arch_remove_memory() which can be dropped in the rebased patch > > C) Rebase (https://patchwork.kernel.org/patch/10962589/) [v3, 09/11] > > - hot-remove series moves arch_remove_memory() before memblock_[free|remove]() > - So remove_memory_block_devices() should be moved before arch_remove_memory() > in it's new position > > David, > > Please do let me know if the plan sounds good or you have some other suggestions. That's exactly what I had in mind :) Andrew, you can drop my series and pick up Anshumans series first. I can then rebase and resend. Cheers!
This series enables memory hot remove on arm64 after fixing a memblock removal ordering problem in generic __remove_memory() and one possible arm64 platform specific kernel page table race condition. This series is based on latest v5.2-rc2 tag. Testing: Memory hot remove has been tested on arm64 for 4K, 16K, 64K page config options with all possible CONFIG_ARM64_VA_BITS and CONFIG_PGTABLE_LEVELS combinations. Its only build tested on non-arm64 platforms. Changes in V5: - Have some agreement [1] over using memory_hotplug_lock for arm64 ptdump - Change 7ba36eccb3f8 ("arm64/mm: Inhibit huge-vmap with ptdump") already merged - Dropped the above patch from this series - Fixed indentation problem in arch_[add|remove]_memory() as per David - Collected all new Acked-by tags Changes in V4: (https://lkml.org/lkml/2019/5/20/19) - Implemented most of the suggestions from Mark Rutland - Interchanged patch [PATCH 2/4] <---> [PATCH 3/4] and updated commit message - Moved CONFIG_PGTABLE_LEVELS inside free_[pud|pmd]_table() - Used READ_ONCE() in missing instances while accessing page table entries - s/p???_present()/p???_none() for checking valid kernel page table entries - WARN_ON() when an entry is !p???_none() and !p???_present() at the same time - Updated memory hot-remove commit message with additional details as suggested - Rebased the series on 5.2-rc1 with hotplug changes from David and Michal Hocko - Collected all new Acked-by tags Changes in V3: (https://lkml.org/lkml/2019/5/14/197) - 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 condition 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) [1] https://lkml.org/lkml/2019/5/28/584 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 arch/arm64/Kconfig | 3 + arch/arm64/mm/mmu.c | 211 ++++++++++++++++++++++++++++++++++++++++- arch/arm64/mm/ptdump_debugfs.c | 3 + mm/memory_hotplug.c | 2 +- 4 files changed, 216 insertions(+), 3 deletions(-)