Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost.
Avoid this problem by not deferring struct page initialization when running as Xen pv guest.
Cc: stable@vger.kernel.org #4.15 Signed-off-by: Juergen Gross jgross@suse.com --- mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 81e18ceef579..681d504b9a40 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -347,6 +347,9 @@ static inline bool update_defer_init(pg_data_t *pgdat, /* Always populate low zones for address-constrained allocations */ if (zone_end < pgdat_end_pfn(pgdat)) return true; + /* Xen PV domains need page structures early */ + if (xen_pv_domain()) + return true; (*nr_initialised)++; if ((*nr_initialised > pgdat->static_init_pgcnt) && (pfn & (PAGES_PER_SECTION - 1)) == 0) {
[CC Pavel]
On Fri 16-02-18 14:37:26, Juergen Gross wrote:
Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost.
Could you be more specific please?
Avoid this problem by not deferring struct page initialization when running as Xen pv guest.
Cc: stable@vger.kernel.org #4.15
Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap")
please
Signed-off-by: Juergen Gross jgross@suse.com
mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 81e18ceef579..681d504b9a40 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -347,6 +347,9 @@ static inline bool update_defer_init(pg_data_t *pgdat, /* Always populate low zones for address-constrained allocations */ if (zone_end < pgdat_end_pfn(pgdat)) return true;
- /* Xen PV domains need page structures early */
- if (xen_pv_domain())
return true;-- 2.13.6
On 16/02/18 14:59, Michal Hocko wrote:
[CC Pavel]
On Fri 16-02-18 14:37:26, Juergen Gross wrote:
Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost.
Could you be more specific please?
In which way? Do you want to see the resulting crash in the commit message or some more background information?
Avoid this problem by not deferring struct page initialization when running as Xen pv guest.
Cc: stable@vger.kernel.org #4.15
Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap")
please
Okay.
Juergen
On 02/16/2018 09:02 AM, Juergen Gross wrote:
On 16/02/18 14:59, Michal Hocko wrote:
[CC Pavel]
On Fri 16-02-18 14:37:26, Juergen Gross wrote:
Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost.
Could you be more specific please?
In which way? Do you want to see the resulting crash in the commit message or some more background information?
Hi Juergen,
Could you please provide details how to reproduce the problem, and crash message. Also, information about where exactly xen access struct pages before deferred pages are initialized.
Thank you, Pasha
Avoid this problem by not deferring struct page initialization when running as Xen pv guest.
Cc: stable@vger.kernel.org #4.15
Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap")
please
Okay.
Juergen
On Fri 16-02-18 15:02:17, Juergen Gross wrote:
On 16/02/18 14:59, Michal Hocko wrote:
[CC Pavel]
On Fri 16-02-18 14:37:26, Juergen Gross wrote:
Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing memory during allocation in vmemmap") broke Xen pv domains in some configurations, as the "Pinned" information in struct page of early page tables could get lost.
Could you be more specific please?
In which way? Do you want to see the resulting crash in the commit message or some more background information?
ideally both.
Hi Juergen,
I love your patch! Yet something to improve:
[auto build test ERROR on mmotm/master] [also build test ERROR on v4.16-rc1 next-20180216] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Juergen-Gross/mm-don-t-defer-struct... base: git://git.cmpxchg.org/linux-mmotm.git master config: x86_64-randconfig-x017-201807 (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=x86_64
All errors (new ones prefixed by >>):
mm/page_alloc.c: In function 'update_defer_init':
mm/page_alloc.c:352:6: error: implicit declaration of function 'xen_pv_domain'; did you mean 'del_dma_domain'? [-Werror=implicit-function-declaration]
if (xen_pv_domain()) ^~~~~~~~~~~~~ del_dma_domain cc1: some warnings being treated as errors
vim +352 mm/page_alloc.c
339 340 /* 341 * Returns false when the remaining initialisation should be deferred until 342 * later in the boot cycle when it can be parallelised. 343 */ 344 static inline bool update_defer_init(pg_data_t *pgdat, 345 unsigned long pfn, unsigned long zone_end, 346 unsigned long *nr_initialised) 347 { 348 /* Always populate low zones for address-constrained allocations */ 349 if (zone_end < pgdat_end_pfn(pgdat)) 350 return true; 351 /* Xen PV domains need page structures early */
352 if (xen_pv_domain())
353 return true; 354 (*nr_initialised)++; 355 if ((*nr_initialised > pgdat->static_init_pgcnt) && 356 (pfn & (PAGES_PER_SECTION - 1)) == 0) { 357 pgdat->first_deferred_pfn = pfn; 358 return false; 359 } 360 361 return true; 362 } 363 #else 364 static inline void reset_deferred_meminit(pg_data_t *pgdat) 365 { 366 } 367
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Juergen,
I love your patch! Yet something to improve:
[auto build test ERROR on mmotm/master] [also build test ERROR on v4.16-rc1 next-20180216] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Juergen-Gross/mm-don-t-defer-struct... base: git://git.cmpxchg.org/linux-mmotm.git master config: i386-randconfig-x010-201807 (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=i386
All errors (new ones prefixed by >>):
mm/page_alloc.c: In function 'update_defer_init':
mm/page_alloc.c:352:6: error: implicit declaration of function 'xen_pv_domain' [-Werror=implicit-function-declaration]
if (xen_pv_domain()) ^~~~~~~~~~~~~ Cyclomatic Complexity 5 include/linux/compiler.h:__read_once_size Cyclomatic Complexity 5 include/linux/compiler.h:__write_once_size Cyclomatic Complexity 2 arch/x86/include/asm/bitops.h:set_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:__set_bit Cyclomatic Complexity 2 arch/x86/include/asm/bitops.h:clear_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:__clear_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:constant_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:variable_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:__ffs Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls Cyclomatic Complexity 1 arch/x86/include/asm/arch_hweight.h:__arch_hweight32 Cyclomatic Complexity 2 include/linux/bitops.h:hweight_long Cyclomatic Complexity 1 include/linux/bitops.h:fls_long Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u32 Cyclomatic Complexity 3 include/linux/log2.h:is_power_of_2 Cyclomatic Complexity 1 include/linux/log2.h:__roundup_pow_of_two Cyclomatic Complexity 1 include/linux/log2.h:__rounddown_pow_of_two Cyclomatic Complexity 1 include/linux/list.h:INIT_LIST_HEAD Cyclomatic Complexity 1 include/linux/list.h:__list_del Cyclomatic Complexity 1 include/linux/list.h:list_empty Cyclomatic Complexity 1 arch/x86/include/asm/current.h:get_current Cyclomatic Complexity 3 include/linux/string.h:memset Cyclomatic Complexity 1 arch/x86/include/asm/page_32.h:clear_page Cyclomatic Complexity 1 include/asm-generic/getorder.h:__get_order Cyclomatic Complexity 3 include/linux/bitmap.h:bitmap_weight Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:atomic_read Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:atomic_set Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:atomic_add Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:atomic_sub_and_test Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:atomic_dec_and_test Cyclomatic Complexity 1 include/asm-generic/atomic-long.h:atomic_long_read Cyclomatic Complexity 1 include/linux/jump_label.h:static_key_count Cyclomatic Complexity 2 include/linux/jump_label.h:static_key_false Cyclomatic Complexity 1 arch/x86/include/asm/paravirt.h:arch_local_save_flags Cyclomatic Complexity 1 arch/x86/include/asm/paravirt.h:arch_local_irq_restore Cyclomatic Complexity 1 arch/x86/include/asm/paravirt.h:arch_local_irq_disable Cyclomatic Complexity 1 arch/x86/include/asm/paravirt.h:arch_local_irq_save Cyclomatic Complexity 1 include/linux/err.h:PTR_ERR Cyclomatic Complexity 1 arch/x86/include/asm/processor.h:rep_nop Cyclomatic Complexity 1 arch/x86/include/asm/processor.h:cpu_relax Cyclomatic Complexity 1 arch/x86/include/asm/processor.h:prefetchw Cyclomatic Complexity 1 arch/x86/include/asm/preempt.h:preempt_count Cyclomatic Complexity 5 arch/x86/include/asm/preempt.h:__preempt_count_add Cyclomatic Complexity 1 arch/x86/include/asm/preempt.h:__preempt_count_dec_and_test Cyclomatic Complexity 1 arch/x86/include/asm/preempt.h:should_resched Cyclomatic Complexity 1 include/linux/spinlock.h:spinlock_check Cyclomatic Complexity 1 include/linux/spinlock.h:spin_lock Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock_irqrestore Cyclomatic Complexity 1 include/linux/nodemask.h:__nodemask_pr_numnodes Cyclomatic Complexity 2 include/linux/nodemask.h:__nodemask_pr_bits Cyclomatic Complexity 1 include/linux/nodemask.h:__nodes_weight Cyclomatic Complexity 1 include/linux/nodemask.h:node_state Cyclomatic Complexity 1 include/linux/nodemask.h:node_set_state Cyclomatic Complexity 1 include/linux/nodemask.h:num_node_state Cyclomatic Complexity 1 include/linux/mmzone.h:zone_end_pfn Cyclomatic Complexity 3 include/linux/mmzone.h:zone_spans_pfn Cyclomatic Complexity 1 include/linux/mmzone.h:zone_is_initialized Cyclomatic Complexity 1 include/linux/mmzone.h:node_lruvec Cyclomatic Complexity 1 include/linux/mmzone.h:pgdat_end_pfn Cyclomatic Complexity 1 include/linux/rcupdate.h:rcu_read_lock_sched_notrace Cyclomatic Complexity 1 include/linux/debugobjects.h:debug_check_no_obj_freed Cyclomatic Complexity 1 include/linux/workqueue.h:__init_work Cyclomatic Complexity 1 include/linux/memory_hotplug.h:pgdat_resize_init Cyclomatic Complexity 1 include/linux/memory_hotplug.h:zone_span_seqbegin Cyclomatic Complexity 1 include/linux/memory_hotplug.h:zone_span_seqretry Cyclomatic Complexity 1 include/linux/memory_hotplug.h:zone_seqlock_init Cyclomatic Complexity 1 include/linux/memory_hotplug.h:movable_node_is_enabled Cyclomatic Complexity 1 include/linux/mmzone.h:managed_zone Cyclomatic Complexity 1 include/linux/mmzone.h:populated_zone Cyclomatic Complexity 1 include/linux/mmzone.h:is_highmem_idx Cyclomatic Complexity 1 include/linux/mmzone.h:is_highmem Cyclomatic Complexity 1 include/linux/mmzone.h:zonelist_zone Cyclomatic Complexity 1 include/linux/mmzone.h:zonelist_zone_idx Cyclomatic Complexity 3 include/linux/mmzone.h:next_zones_zonelist Cyclomatic Complexity 1 include/linux/mmzone.h:first_zones_zonelist Cyclomatic Complexity 1 include/linux/mmzone.h:pfn_to_section_nr Cyclomatic Complexity 2 include/linux/mmzone.h:__nr_to_section Cyclomatic Complexity 1 include/linux/mmzone.h:__section_mem_map_addr Cyclomatic Complexity 3 include/linux/mmzone.h:valid_section Cyclomatic Complexity 1 include/linux/mmzone.h:__pfn_to_section Cyclomatic Complexity 2 include/linux/mmzone.h:pfn_valid Cyclomatic Complexity 1 arch/x86/include/asm/topology.h:numa_node_id Cyclomatic Complexity 1 include/linux/topology.h:numa_mem_id Cyclomatic Complexity 1 include/linux/gfp.h:gfp_zonelist Cyclomatic Complexity 1 include/linux/gfp.h:node_zonelist Cyclomatic Complexity 1 include/linux/gfp.h:arch_free_page Cyclomatic Complexity 1 include/linux/gfp.h:arch_alloc_page Cyclomatic Complexity 1 include/linux/gfp.h:pm_suspended_storage Cyclomatic Complexity 1 include/linux/page-flags.h:PageTail Cyclomatic Complexity 3 include/linux/page-flags.h:PageCompound Cyclomatic Complexity 1 include/linux/page-flags.h:PageLRU Cyclomatic Complexity 1 include/linux/page-flags.h:PageReserved Cyclomatic Complexity 1 include/linux/page-flags.h:SetPageReserved Cyclomatic Complexity 1 include/linux/page-flags.h:ClearPageReserved Cyclomatic Complexity 1 include/linux/page-flags.h:__ClearPageReserved Cyclomatic Complexity 1 include/linux/page-flags.h:PageHighMem Cyclomatic Complexity 1 include/linux/page-flags.h:PageHWPoison
vim +/xen_pv_domain +352 mm/page_alloc.c
339 340 /* 341 * Returns false when the remaining initialisation should be deferred until 342 * later in the boot cycle when it can be parallelised. 343 */ 344 static inline bool update_defer_init(pg_data_t *pgdat, 345 unsigned long pfn, unsigned long zone_end, 346 unsigned long *nr_initialised) 347 { 348 /* Always populate low zones for address-constrained allocations */ 349 if (zone_end < pgdat_end_pfn(pgdat)) 350 return true; 351 /* Xen PV domains need page structures early */
352 if (xen_pv_domain())
353 return true; 354 (*nr_initialised)++; 355 if ((*nr_initialised > pgdat->static_init_pgcnt) && 356 (pfn & (PAGES_PER_SECTION - 1)) == 0) { 357 pgdat->first_deferred_pfn = pfn; 358 return false; 359 } 360 361 return true; 362 } 363 #else 364 static inline void reset_deferred_meminit(pg_data_t *pgdat) 365 { 366 } 367
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Mon, 19 Feb 2018 02:45:27 +0800 kbuild test robot lkp@intel.com wrote:
[auto build test ERROR on mmotm/master] [also build test ERROR on v4.16-rc1 next-20180216] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Juergen-Gross/mm-don-t-defer-struct... base: git://git.cmpxchg.org/linux-mmotm.git master config: i386-randconfig-x010-201807 (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=i386
All errors (new ones prefixed by >>):
mm/page_alloc.c: In function 'update_defer_init':
mm/page_alloc.c:352:6: error: implicit declaration of function 'xen_pv_domain' [-Werror=implicit-function-declaration]
if (xen_pv_domain()) ^~~~~~~~~~~~~
I think I already fixed this.
From: Andrew Morton akpm@linux-foundation.org Subject: mm-dont-defer-struct-page-initialization-for-xen-pv-guests-fix
explicitly include xen.h
Cc: Juergen Gross jgross@suse.com Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+)
diff -puN mm/page_alloc.c~mm-dont-defer-struct-page-initialization-for-xen-pv-guests-fix mm/page_alloc.c --- a/mm/page_alloc.c~mm-dont-defer-struct-page-initialization-for-xen-pv-guests-fix +++ a/mm/page_alloc.c @@ -46,6 +46,7 @@ #include <linux/stop_machine.h> #include <linux/sort.h> #include <linux/pfn.h> +#include <xen/xen.h> #include <linux/backing-dev.h> #include <linux/fault-inject.h> #include <linux/page-isolation.h> _
linux-stable-mirror@lists.linaro.org
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