| Message ID | 20240216111502.79759-1-byungchul@sk.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/vmscan: Fix a bug calling wakeup_kswapd() with a wrong zone index | expand |
On 2024/2/16 19:15, Byungchul Park wrote: > With numa balancing on, when a numa system is running where a numa node > doesn't have its local memory so it has no managed zones, the following > oops has been observed. It's because wakeup_kswapd() is called with a > wrong zone index, -1. Fixed it by checking the index before calling > wakeup_kswapd(). > >> BUG: unable to handle page fault for address: 00000000000033f3 >> #PF: supervisor read access in kernel mode >> #PF: error_code(0x0000) - not-present page >> PGD 0 P4D 0 >> Oops: 0000 [#1] PREEMPT SMP NOPTI >> CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >> rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 >> RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) >> Code: (omitted) >> RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 >> RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 >> RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff >> R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 >> FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> PKRU: 55555554 >> Call Trace: >> <TASK> >> ? __die >> ? page_fault_oops >> ? __pte_offset_map_lock >> ? exc_page_fault >> ? asm_exc_page_fault >> ? wakeup_kswapd >> migrate_misplaced_page >> __handle_mm_fault >> handle_mm_fault >> do_user_addr_fault >> exc_page_fault >> asm_exc_page_fault >> RIP: 0033:0x55b897ba0808 >> Code: (omitted) >> RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 >> RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 >> RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 >> RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 >> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 >> R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 >> </TASK> > > Signed-off-by: Byungchul Park <byungchul@sk.com> > Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com> > Cc: stable@vger.kernel.org > Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system") This means that there is no memory on the target node？ if so, we can add a check at the beginning to avoid calling unnecessary migrate_misplaced_folio(). diff --git a/mm/memory.c b/mm/memory.c index e95503d7544e..a64a1aac463f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5182,7 +5182,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) else last_cpupid = folio_last_cpupid(folio); target_nid = numa_migrate_prep(folio, vma, vmf->address, nid, &flags); - if (target_nid == NUMA_NO_NODE) { + if (target_nid == NUMA_NO_NODE || !node_state(target_nid, N_MEMORY)) { folio_put(folio); goto out_map; } (similar changes for do_huge_pmd_numa_page()) > --- > mm/migrate.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index fbc8586ed735..51ee6865b0f6 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) > if (managed_zone(pgdat->node_zones + z)) > break; > } > + > + /* > + * If there are no managed zones, it should not proceed > + * further. > + */ > + if (z < 0) > + return 0; > + > wakeup_kswapd(pgdat->node_zones + z, 0, > folio_order(folio), ZONE_MOVABLE); > return 0;
On Mon, Feb 19, 2024 at 02:25:11PM +0800, Baolin Wang wrote: > > > On 2024/2/16 19:15, Byungchul Park wrote: > > With numa balancing on, when a numa system is running where a numa node > > doesn't have its local memory so it has no managed zones, the following > > oops has been observed. It's because wakeup_kswapd() is called with a > > wrong zone index, -1. Fixed it by checking the index before calling > > wakeup_kswapd(). > > > > > BUG: unable to handle page fault for address: 00000000000033f3 > > > #PF: supervisor read access in kernel mode > > > #PF: error_code(0x0000) - not-present page > > > PGD 0 P4D 0 > > > Oops: 0000 [#1] PREEMPT SMP NOPTI > > > CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > > rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > > > RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) > > > Code: (omitted) > > > RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 > > > RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 > > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 > > > RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff > > > R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 > > > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 > > > FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 > > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 > > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > PKRU: 55555554 > > > Call Trace: > > > <TASK> > > > ? __die > > > ? page_fault_oops > > > ? __pte_offset_map_lock > > > ? exc_page_fault > > > ? asm_exc_page_fault > > > ? wakeup_kswapd > > > migrate_misplaced_page > > > __handle_mm_fault > > > handle_mm_fault > > > do_user_addr_fault > > > exc_page_fault > > > asm_exc_page_fault > > > RIP: 0033:0x55b897ba0808 > > > Code: (omitted) > > > RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 > > > RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 > > > RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 > > > RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 > > > R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 > > > R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 > > > </TASK> > > > > Signed-off-by: Byungchul Park <byungchul@sk.com> > > Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com> > > Cc: stable@vger.kernel.org > > Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system") > > This means that there is no memory on the target node？ if so, we can add a > check at the beginning to avoid calling unnecessary > migrate_misplaced_folio(). Right. However, the check is necessary no matter where it comes from. FYI, the fix is going on in another thread: https://lore.kernel.org/lkml/20240216114045.24828-1-byungchul@sk.com/ https://lore.kernel.org/lkml/20240219041920.1183-1-byungchul@sk.com/ Byungchul > diff --git a/mm/memory.c b/mm/memory.c > index e95503d7544e..a64a1aac463f 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5182,7 +5182,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) > else > last_cpupid = folio_last_cpupid(folio); > target_nid = numa_migrate_prep(folio, vma, vmf->address, nid, > &flags); > - if (target_nid == NUMA_NO_NODE) { > + if (target_nid == NUMA_NO_NODE || !node_state(target_nid, N_MEMORY)) > { > folio_put(folio); > goto out_map; > } > > (similar changes for do_huge_pmd_numa_page()) > > > --- > > mm/migrate.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/mm/migrate.c b/mm/migrate.c > > index fbc8586ed735..51ee6865b0f6 100644 > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) > > if (managed_zone(pgdat->node_zones + z)) > > break; > > } > > + > > + /* > > + * If there are no managed zones, it should not proceed > > + * further. > > + */ > > + if (z < 0) > > + return 0; > > + > > wakeup_kswapd(pgdat->node_zones + z, 0, > > folio_order(folio), ZONE_MOVABLE); > > return 0;
On Mon, Feb 19, 2024 at 02:25:11PM +0800, Baolin Wang wrote: > This means that there is no memory on the target node？ if so, we can add a > check at the beginning to avoid calling unnecessary > migrate_misplaced_folio(). > > diff --git a/mm/memory.c b/mm/memory.c > index e95503d7544e..a64a1aac463f 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5182,7 +5182,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) > else > last_cpupid = folio_last_cpupid(folio); > target_nid = numa_migrate_prep(folio, vma, vmf->address, nid, > &flags); > - if (target_nid == NUMA_NO_NODE) { > + if (target_nid == NUMA_NO_NODE || !node_state(target_nid, N_MEMORY)) > { > folio_put(folio); > goto out_map; > } > > (similar changes for do_huge_pmd_numa_page()) With the check in place from [1], numa_migrate_prep() will also return NUMA_NO_NODE, so no need for this one here. And I did not check, but I assume that do_huge_pmd_numa_page() also ends up calling numa_migrate_prep(). [1] https://lore.kernel.org/lkml/20240219041920.1183-1-byungchul@sk.com/
On 2024/2/19 16:11, Oscar Salvador wrote: > On Mon, Feb 19, 2024 at 02:25:11PM +0800, Baolin Wang wrote: >> This means that there is no memory on the target node？ if so, we can add a >> check at the beginning to avoid calling unnecessary >> migrate_misplaced_folio(). >> >> diff --git a/mm/memory.c b/mm/memory.c >> index e95503d7544e..a64a1aac463f 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -5182,7 +5182,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) >> else >> last_cpupid = folio_last_cpupid(folio); >> target_nid = numa_migrate_prep(folio, vma, vmf->address, nid, >> &flags); >> - if (target_nid == NUMA_NO_NODE) { >> + if (target_nid == NUMA_NO_NODE || !node_state(target_nid, N_MEMORY)) >> { >> folio_put(folio); >> goto out_map; >> } >> >> (similar changes for do_huge_pmd_numa_page()) > > With the check in place from [1], numa_migrate_prep() will also return > NUMA_NO_NODE, so no need for this one here. > > And I did not check, but I assume that do_huge_pmd_numa_page() also ends > up calling numa_migrate_prep(). > > [1] https://lore.kernel.org/lkml/20240219041920.1183-1-byungchul@sk.com/ Right. I missed this patch before. So with checking in should_numa_migrate_memory(), I guess current changes in numamigrate_isolate_folio() can also be dropped, it will never hit a memoryless node after the patch [1], no?
Byungchul Park <byungchul@sk.com> writes: > With numa balancing on, when a numa system is running where a numa node > doesn't have its local memory so it has no managed zones, the following > oops has been observed. It's because wakeup_kswapd() is called with a > wrong zone index, -1. Fixed it by checking the index before calling > wakeup_kswapd(). > >> BUG: unable to handle page fault for address: 00000000000033f3 >> #PF: supervisor read access in kernel mode >> #PF: error_code(0x0000) - not-present page >> PGD 0 P4D 0 >> Oops: 0000 [#1] PREEMPT SMP NOPTI >> CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >> rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 >> RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) >> Code: (omitted) >> RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 >> RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 >> RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff >> R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 >> FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> PKRU: 55555554 >> Call Trace: >> <TASK> >> ? __die >> ? page_fault_oops >> ? __pte_offset_map_lock >> ? exc_page_fault >> ? asm_exc_page_fault >> ? wakeup_kswapd >> migrate_misplaced_page >> __handle_mm_fault >> handle_mm_fault >> do_user_addr_fault >> exc_page_fault >> asm_exc_page_fault >> RIP: 0033:0x55b897ba0808 >> Code: (omitted) >> RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 >> RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 >> RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 >> RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 >> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 >> R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 >> </TASK> > > Signed-off-by: Byungchul Park <byungchul@sk.com> > Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com> > Cc: stable@vger.kernel.org > Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system") > --- > mm/migrate.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index fbc8586ed735..51ee6865b0f6 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) > if (managed_zone(pgdat->node_zones + z)) > break; > } > + > + /* > + * If there are no managed zones, it should not proceed > + * further. > + */ > + if (z < 0) > + return 0; > + I think that it's better to check pgdat->nr_zones directly earlier in the function. That is a little easier to be understood. > wakeup_kswapd(pgdat->node_zones + z, 0, > folio_order(folio), ZONE_MOVABLE); > return 0; -- Best Regards, Huang, Ying
On Tue, Feb 20, 2024 at 11:42:31AM +0800, Huang, Ying wrote: > Byungchul Park <byungchul@sk.com> writes: > > > With numa balancing on, when a numa system is running where a numa node > > doesn't have its local memory so it has no managed zones, the following > > oops has been observed. It's because wakeup_kswapd() is called with a > > wrong zone index, -1. Fixed it by checking the index before calling > > wakeup_kswapd(). > > > >> BUG: unable to handle page fault for address: 00000000000033f3 > >> #PF: supervisor read access in kernel mode > >> #PF: error_code(0x0000) - not-present page > >> PGD 0 P4D 0 > >> Oops: 0000 [#1] PREEMPT SMP NOPTI > >> CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 > >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > >> rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > >> RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) > >> Code: (omitted) > >> RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 > >> RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 > >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 > >> RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff > >> R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 > >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 > >> FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 > >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >> CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 > >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >> PKRU: 55555554 > >> Call Trace: > >> <TASK> > >> ? __die > >> ? page_fault_oops > >> ? __pte_offset_map_lock > >> ? exc_page_fault > >> ? asm_exc_page_fault > >> ? wakeup_kswapd > >> migrate_misplaced_page > >> __handle_mm_fault > >> handle_mm_fault > >> do_user_addr_fault > >> exc_page_fault > >> asm_exc_page_fault > >> RIP: 0033:0x55b897ba0808 > >> Code: (omitted) > >> RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 > >> RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 > >> RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 > >> RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 > >> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 > >> R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 > >> </TASK> > > > > Signed-off-by: Byungchul Park <byungchul@sk.com> > > Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com> > > Cc: stable@vger.kernel.org > > Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system") > > --- > > mm/migrate.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/mm/migrate.c b/mm/migrate.c > > index fbc8586ed735..51ee6865b0f6 100644 > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) > > if (managed_zone(pgdat->node_zones + z)) > > break; > > } > > + > > + /* > > + * If there are no managed zones, it should not proceed > > + * further. > > + */ > > + if (z < 0) > > + return 0; > > + > > I think that it's better to check pgdat->nr_zones directly earlier in > the function. That is a little easier to be understood. No. No matter what the value of ->nr_zones is, the oops is going to happen if there are no managed zones by any reason. Byungchul > > wakeup_kswapd(pgdat->node_zones + z, 0, > > folio_order(folio), ZONE_MOVABLE); > > return 0; > > -- > Best Regards, > Huang, Ying
Byungchul Park <byungchul@sk.com> writes: > On Tue, Feb 20, 2024 at 11:42:31AM +0800, Huang, Ying wrote: >> Byungchul Park <byungchul@sk.com> writes: >> >> > With numa balancing on, when a numa system is running where a numa node >> > doesn't have its local memory so it has no managed zones, the following >> > oops has been observed. It's because wakeup_kswapd() is called with a >> > wrong zone index, -1. Fixed it by checking the index before calling >> > wakeup_kswapd(). >> > >> >> BUG: unable to handle page fault for address: 00000000000033f3 >> >> #PF: supervisor read access in kernel mode >> >> #PF: error_code(0x0000) - not-present page >> >> PGD 0 P4D 0 >> >> Oops: 0000 [#1] PREEMPT SMP NOPTI >> >> CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 >> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >> >> rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 >> >> RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) >> >> Code: (omitted) >> >> RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 >> >> RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 >> >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 >> >> RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff >> >> R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 >> >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 >> >> FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 >> >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> >> CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 >> >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> >> PKRU: 55555554 >> >> Call Trace: >> >> <TASK> >> >> ? __die >> >> ? page_fault_oops >> >> ? __pte_offset_map_lock >> >> ? exc_page_fault >> >> ? asm_exc_page_fault >> >> ? wakeup_kswapd >> >> migrate_misplaced_page >> >> __handle_mm_fault >> >> handle_mm_fault >> >> do_user_addr_fault >> >> exc_page_fault >> >> asm_exc_page_fault >> >> RIP: 0033:0x55b897ba0808 >> >> Code: (omitted) >> >> RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 >> >> RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 >> >> RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 >> >> RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 >> >> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 >> >> R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 >> >> </TASK> >> > >> > Signed-off-by: Byungchul Park <byungchul@sk.com> >> > Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com> >> > Cc: stable@vger.kernel.org >> > Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system") >> > --- >> > mm/migrate.c | 8 ++++++++ >> > 1 file changed, 8 insertions(+) >> > >> > diff --git a/mm/migrate.c b/mm/migrate.c >> > index fbc8586ed735..51ee6865b0f6 100644 >> > --- a/mm/migrate.c >> > +++ b/mm/migrate.c >> > @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) >> > if (managed_zone(pgdat->node_zones + z)) >> > break; >> > } >> > + >> > + /* >> > + * If there are no managed zones, it should not proceed >> > + * further. >> > + */ >> > + if (z < 0) >> > + return 0; >> > + >> >> I think that it's better to check pgdat->nr_zones directly earlier in >> the function. That is a little easier to be understood. > > No. No matter what the value of ->nr_zones is, the oops is going to > happen if there are no managed zones by any reason. Yes. You are right. Sorry for noise. -- Best Regards, Huang, Ying > Byungchul > >> > wakeup_kswapd(pgdat->node_zones + z, 0, >> > folio_order(folio), ZONE_MOVABLE); >> > return 0; >> >> -- >> Best Regards, >> Huang, Ying
diff --git a/mm/migrate.c b/mm/migrate.c index fbc8586ed735..51ee6865b0f6 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2825,6 +2825,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio) if (managed_zone(pgdat->node_zones + z)) break; } + + /* + * If there are no managed zones, it should not proceed + * further. + */ + if (z < 0) + return 0; + wakeup_kswapd(pgdat->node_zones + z, 0, folio_order(folio), ZONE_MOVABLE); return 0;