| Message ID | 20240321032747.87694-1-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | mm: migrate: support poison recover from migrate folio | expand |
Hi, since rfcv2, there is no more changes, kindly ping, any comments, thanks all. On 2024/3/21 11:27, Kefeng Wang wrote: > The folio migration is widely used in kernel, memory compaction, memory > hotplug, soft offline page, numa balance, memory demote/promotion, etc, > but once access a poisoned source folio when migrating, the kerenl will > panic. > > There is a mechanism in the kernel to recover from uncorrectable memory > errors, ARCH_HAS_COPY_MC(Machine Check Safe Memory Copy), which is already > used in NVDIMM or core-mm paths(eg, CoW, khugepaged, coredump, ksm copy), > see copy_mc_to_{user,kernel}, copy_mc_{user_}highpage callers. > > This series of patches provide the recovery mechanism from folio copy for > the widely used folio migration. Please note, because folio migration is > no guarantee of success, so we could chose to make folio migration tolerant > of memory failures, adding folio_mc_copy() which is a #MC versions of > folio_copy(), once accessing a poisoned source folio, we could return error > and make the folio migration fail, and this could avoid the similar panic > shown below. > > CPU: 1 PID: 88343 Comm: test_softofflin Kdump: loaded Not tainted 6.6.0 > pc : copy_page+0x10/0xc0 > lr : copy_highpage+0x38/0x50 > ... > Call trace: > copy_page+0x10/0xc0 > folio_copy+0x78/0x90 > migrate_folio_extra+0x54/0xa0 > move_to_new_folio+0xd8/0x1f0 > migrate_folio_move+0xb8/0x300 > migrate_pages_batch+0x528/0x788 > migrate_pages_sync+0x8c/0x258 > migrate_pages+0x440/0x528 > soft_offline_in_use_page+0x2ec/0x3c0 > soft_offline_page+0x238/0x310 > soft_offline_page_store+0x6c/0xc0 > dev_attr_store+0x20/0x40 > sysfs_kf_write+0x4c/0x68 > kernfs_fop_write_iter+0x130/0x1c8 > new_sync_write+0xa4/0x138 > vfs_write+0x238/0x2d8 > ksys_write+0x74/0x110 > > v1: > - no change, resend and rebased on 6.9-rc1 > > rfcv2: > - Separate __migrate_device_pages() cleanup from patch "remove > migrate_folio_extra()", suggested by Matthew > - Split folio_migrate_mapping(), move refcount check/freeze out > of folio_migrate_mapping(), suggested by Matthew > - add RB > > Kefeng Wang (11): > mm: migrate: simplify __buffer_migrate_folio() > mm: migrate_device: use more folio in __migrate_device_pages() > mm: migrate_device: unify migrate folio for MIGRATE_SYNC_NO_COPY > mm: migrate: remove migrate_folio_extra() > mm: remove MIGRATE_SYNC_NO_COPY mode > mm: migrate: split folio_migrate_mapping() > mm: add folio_mc_copy() > mm: migrate: support poisoned recover from migrate folio > fs: hugetlbfs: support poison recover from hugetlbfs_migrate_folio() > mm: migrate: remove folio_migrate_copy() > fs: aio: add explicit check for large folio in aio_migrate_folio() > > fs/aio.c | 15 ++-- > fs/hugetlbfs/inode.c | 5 +- > include/linux/migrate.h | 3 - > include/linux/migrate_mode.h | 5 -- > include/linux/mm.h | 1 + > mm/balloon_compaction.c | 8 -- > mm/migrate.c | 157 +++++++++++++++++------------------ > mm/migrate_device.c | 28 +++---- > mm/util.c | 20 +++++ > mm/zsmalloc.c | 8 -- > 10 files changed, 115 insertions(+), 135 deletions(-) >
The folio migration is widely used in kernel, memory compaction, memory hotplug, soft offline page, numa balance, memory demote/promotion, etc, but once access a poisoned source folio when migrating, the kerenl will panic. There is a mechanism in the kernel to recover from uncorrectable memory errors, ARCH_HAS_COPY_MC(Machine Check Safe Memory Copy), which is already used in NVDIMM or core-mm paths(eg, CoW, khugepaged, coredump, ksm copy), see copy_mc_to_{user,kernel}, copy_mc_{user_}highpage callers. This series of patches provide the recovery mechanism from folio copy for the widely used folio migration. Please note, because folio migration is no guarantee of success, so we could chose to make folio migration tolerant of memory failures, adding folio_mc_copy() which is a #MC versions of folio_copy(), once accessing a poisoned source folio, we could return error and make the folio migration fail, and this could avoid the similar panic shown below. CPU: 1 PID: 88343 Comm: test_softofflin Kdump: loaded Not tainted 6.6.0 pc : copy_page+0x10/0xc0 lr : copy_highpage+0x38/0x50 ... Call trace: copy_page+0x10/0xc0 folio_copy+0x78/0x90 migrate_folio_extra+0x54/0xa0 move_to_new_folio+0xd8/0x1f0 migrate_folio_move+0xb8/0x300 migrate_pages_batch+0x528/0x788 migrate_pages_sync+0x8c/0x258 migrate_pages+0x440/0x528 soft_offline_in_use_page+0x2ec/0x3c0 soft_offline_page+0x238/0x310 soft_offline_page_store+0x6c/0xc0 dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x130/0x1c8 new_sync_write+0xa4/0x138 vfs_write+0x238/0x2d8 ksys_write+0x74/0x110 v1: - no change, resend and rebased on 6.9-rc1 rfcv2: - Separate __migrate_device_pages() cleanup from patch "remove migrate_folio_extra()", suggested by Matthew - Split folio_migrate_mapping(), move refcount check/freeze out of folio_migrate_mapping(), suggested by Matthew - add RB Kefeng Wang (11): mm: migrate: simplify __buffer_migrate_folio() mm: migrate_device: use more folio in __migrate_device_pages() mm: migrate_device: unify migrate folio for MIGRATE_SYNC_NO_COPY mm: migrate: remove migrate_folio_extra() mm: remove MIGRATE_SYNC_NO_COPY mode mm: migrate: split folio_migrate_mapping() mm: add folio_mc_copy() mm: migrate: support poisoned recover from migrate folio fs: hugetlbfs: support poison recover from hugetlbfs_migrate_folio() mm: migrate: remove folio_migrate_copy() fs: aio: add explicit check for large folio in aio_migrate_folio() fs/aio.c | 15 ++-- fs/hugetlbfs/inode.c | 5 +- include/linux/migrate.h | 3 - include/linux/migrate_mode.h | 5 -- include/linux/mm.h | 1 + mm/balloon_compaction.c | 8 -- mm/migrate.c | 157 +++++++++++++++++------------------ mm/migrate_device.c | 28 +++---- mm/util.c | 20 +++++ mm/zsmalloc.c | 8 -- 10 files changed, 115 insertions(+), 135 deletions(-)