Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-17 Thread Joonsoo Kim 
On Wed, Jun 15, 2016 at 11:27:31AM +0900, Joonsoo Kim wrote:
> On Tue, Jun 14, 2016 at 03:10:21PM -0400, Sasha Levin wrote:
> > On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> > > On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> > >> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> > >>> > > From: Joonsoo Kim 
> > >>> > > 
> > >>> > > We don't need to split freepages with holding the zone lock. It 
> > >>> > > will cause
> > >>> > > more contention on zone lock so not desirable.
> > >>> > > 
> > >>> > > Signed-off-by: Joonsoo Kim 
> > >> > 
> > >> > Hey Joonsoo,
> > > Hello, Sasha.
> > >> > 
> > >> > I'm seeing the following corruption/crash which seems to be related to
> > >> > this patch:
> > > Could you tell me why you think that following corruption is related
> > > to this patch? list_del() in __isolate_free_page() is unchanged part.
> > > 
> > > Before this patch, we did it by split_free_page() ->
> > > __isolate_free_page() -> list_del(). With this patch, we do it by
> > > calling __isolate_free_page() directly.
> > 
> > I haven't bisected it, but it's the first time I see this issue and this
> > commit seems to have done related changes that might cause this.
> > 
> > I can go ahead with bisection if you don't think it's related.
> 
> Hmm... I can't find a bug in this patch for now. There are more candidates
> on this area hat changed by me and it would be very helpful if you can
> do bisection.

Hello, Sasha.

You are right! Minchan found the bug in this patch! I will send
updated patch soon.

http://marc.info/?i=20160616100932.GS17127%40bbox

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-17 Thread Joonsoo Kim 
On Wed, Jun 15, 2016 at 11:27:31AM +0900, Joonsoo Kim wrote:
> On Tue, Jun 14, 2016 at 03:10:21PM -0400, Sasha Levin wrote:
> > On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> > > On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> > >> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> > >>> > > From: Joonsoo Kim 
> > >>> > > 
> > >>> > > We don't need to split freepages with holding the zone lock. It 
> > >>> > > will cause
> > >>> > > more contention on zone lock so not desirable.
> > >>> > > 
> > >>> > > Signed-off-by: Joonsoo Kim 
> > >> > 
> > >> > Hey Joonsoo,
> > > Hello, Sasha.
> > >> > 
> > >> > I'm seeing the following corruption/crash which seems to be related to
> > >> > this patch:
> > > Could you tell me why you think that following corruption is related
> > > to this patch? list_del() in __isolate_free_page() is unchanged part.
> > > 
> > > Before this patch, we did it by split_free_page() ->
> > > __isolate_free_page() -> list_del(). With this patch, we do it by
> > > calling __isolate_free_page() directly.
> > 
> > I haven't bisected it, but it's the first time I see this issue and this
> > commit seems to have done related changes that might cause this.
> > 
> > I can go ahead with bisection if you don't think it's related.
> 
> Hmm... I can't find a bug in this patch for now. There are more candidates
> on this area hat changed by me and it would be very helpful if you can
> do bisection.

Hello, Sasha.

You are right! Minchan found the bug in this patch! I will send
updated patch soon.

http://marc.info/?i=20160616100932.GS17127%40bbox

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-14 Thread Joonsoo Kim 
On Tue, Jun 14, 2016 at 03:10:21PM -0400, Sasha Levin wrote:
> On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> > On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> >> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> >>> > > From: Joonsoo Kim 
> >>> > > 
> >>> > > We don't need to split freepages with holding the zone lock. It will 
> >>> > > cause
> >>> > > more contention on zone lock so not desirable.
> >>> > > 
> >>> > > Signed-off-by: Joonsoo Kim 
> >> > 
> >> > Hey Joonsoo,
> > Hello, Sasha.
> >> > 
> >> > I'm seeing the following corruption/crash which seems to be related to
> >> > this patch:
> > Could you tell me why you think that following corruption is related
> > to this patch? list_del() in __isolate_free_page() is unchanged part.
> > 
> > Before this patch, we did it by split_free_page() ->
> > __isolate_free_page() -> list_del(). With this patch, we do it by
> > calling __isolate_free_page() directly.
> 
> I haven't bisected it, but it's the first time I see this issue and this
> commit seems to have done related changes that might cause this.
> 
> I can go ahead with bisection if you don't think it's related.

Hmm... I can't find a bug in this patch for now. There are more candidates
on this area hat changed by me and it would be very helpful if you can
do bisection.

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-14 Thread Joonsoo Kim 
On Tue, Jun 14, 2016 at 03:10:21PM -0400, Sasha Levin wrote:
> On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> > On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> >> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> >>> > > From: Joonsoo Kim 
> >>> > > 
> >>> > > We don't need to split freepages with holding the zone lock. It will 
> >>> > > cause
> >>> > > more contention on zone lock so not desirable.
> >>> > > 
> >>> > > Signed-off-by: Joonsoo Kim 
> >> > 
> >> > Hey Joonsoo,
> > Hello, Sasha.
> >> > 
> >> > I'm seeing the following corruption/crash which seems to be related to
> >> > this patch:
> > Could you tell me why you think that following corruption is related
> > to this patch? list_del() in __isolate_free_page() is unchanged part.
> > 
> > Before this patch, we did it by split_free_page() ->
> > __isolate_free_page() -> list_del(). With this patch, we do it by
> > calling __isolate_free_page() directly.
> 
> I haven't bisected it, but it's the first time I see this issue and this
> commit seems to have done related changes that might cause this.
> 
> I can go ahead with bisection if you don't think it's related.

Hmm... I can't find a bug in this patch for now. There are more candidates
on this area hat changed by me and it would be very helpful if you can
do bisection.

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-14 Thread Sasha Levin 
On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
>> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
>>> > > From: Joonsoo Kim 
>>> > > 
>>> > > We don't need to split freepages with holding the zone lock. It will 
>>> > > cause
>>> > > more contention on zone lock so not desirable.
>>> > > 
>>> > > Signed-off-by: Joonsoo Kim 
>> > 
>> > Hey Joonsoo,
> Hello, Sasha.
>> > 
>> > I'm seeing the following corruption/crash which seems to be related to
>> > this patch:
> Could you tell me why you think that following corruption is related
> to this patch? list_del() in __isolate_free_page() is unchanged part.
> 
> Before this patch, we did it by split_free_page() ->
> __isolate_free_page() -> list_del(). With this patch, we do it by
> calling __isolate_free_page() directly.

I haven't bisected it, but it's the first time I see this issue and this
commit seems to have done related changes that might cause this.

I can go ahead with bisection if you don't think it's related.


Thanks,
Sasha

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-14 Thread Sasha Levin 
On 06/14/2016 01:52 AM, Joonsoo Kim wrote:
> On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
>> > On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
>>> > > From: Joonsoo Kim 
>>> > > 
>>> > > We don't need to split freepages with holding the zone lock. It will 
>>> > > cause
>>> > > more contention on zone lock so not desirable.
>>> > > 
>>> > > Signed-off-by: Joonsoo Kim 
>> > 
>> > Hey Joonsoo,
> Hello, Sasha.
>> > 
>> > I'm seeing the following corruption/crash which seems to be related to
>> > this patch:
> Could you tell me why you think that following corruption is related
> to this patch? list_del() in __isolate_free_page() is unchanged part.
> 
> Before this patch, we did it by split_free_page() ->
> __isolate_free_page() -> list_del(). With this patch, we do it by
> calling __isolate_free_page() directly.

I haven't bisected it, but it's the first time I see this issue and this
commit seems to have done related changes that might cause this.

I can go ahead with bisection if you don't think it's related.


Thanks,
Sasha

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-13 Thread Joonsoo Kim 
On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> > From: Joonsoo Kim 
> > 
> > We don't need to split freepages with holding the zone lock. It will cause
> > more contention on zone lock so not desirable.
> > 
> > Signed-off-by: Joonsoo Kim 
> 
> Hey Joonsoo,

Hello, Sasha.
> 
> I'm seeing the following corruption/crash which seems to be related to
> this patch:

Could you tell me why you think that following corruption is related
to this patch? list_del() in __isolate_free_page() is unchanged part.

Before this patch, we did it by split_free_page() ->
__isolate_free_page() -> list_del(). With this patch, we do it by
calling __isolate_free_page() directly.

Thanks.


> [ 3777.807224] [ cut here ]
> 
> [ 3777.807834] WARNING: CPU: 5 PID: 3270 at lib/list_debug.c:62 
> __list_del_entry+0x14e/0x280
> 
> [ 3777.808562] list_del corruption. next->prev should be ea0004a76120, 
> but was ea0004a72120
> 
> [ 3777.809498] Modules linked in:
> 
> [ 3777.809923] CPU: 5 PID: 3270 Comm: khugepaged Tainted: GW   
> 4.7.0-rc2-next-20160609-sasha-00024-g30ecaf6 #3101
> 
> [ 3777.811014]  1100f9315d7b 0bb7299a 8807c98aec60 
> a0035b2b
> 
> [ 3777.811816]  0005 fbfff5630bf4 41b58ab3 
> aaaf18e0
> 
> [ 3777.812662]  a00359bc 9e54d4a0 a8b2ade0 
> 8807c98aece0
> 
> [ 3777.813493] Call Trace:
> 
> [ 3777.813796] dump_stack (lib/dump_stack.c:53)
> [ 3777.814310] ? arch_local_irq_restore 
> (./arch/x86/include/asm/paravirt.h:134)
> [ 3777.814947] ? is_module_text_address (kernel/module.c:4185)
> [ 3777.815571] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.816174] ? vprintk_default (kernel/printk/printk.c:1886)
> [ 3777.816761] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.817381] __warn (kernel/panic.c:518)
> [ 3777.817867] warn_slowpath_fmt (kernel/panic.c:526)
> [ 3777.818428] ? __warn (kernel/panic.c:526)
> [ 3777.819001] ? __schedule (kernel/sched/core.c:2858 
> kernel/sched/core.c:3345)
> [ 3777.819541] __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.820116] ? __list_add (lib/list_debug.c:45)
> [ 3777.820721] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
> [ 3777.821347] list_del (lib/list_debug.c:78)
> [ 3777.821829] __isolate_free_page (mm/page_alloc.c:2514)
> [ 3777.822400] ? __zone_watermark_ok (mm/page_alloc.c:2493)
> [ 3777.823007] isolate_freepages_block (mm/compaction.c:498)
> [ 3777.823629] ? compact_unlock_should_abort (mm/compaction.c:417)
> [ 3777.824312] compaction_alloc (mm/compaction.c:1112 mm/compaction.c:1156)
> [ 3777.824871] ? isolate_freepages_block (mm/compaction.c:1146)
> [ 3777.825512] ? __page_cache_release (mm/swap.c:73)
> [ 3777.826127] migrate_pages (mm/migrate.c:1079 mm/migrate.c:1325)
> [ 3777.826712] ? __reset_isolation_suitable (mm/compaction.c:1175)
> [ 3777.827398] ? isolate_freepages_block (mm/compaction.c:1146)
> [ 3777.828109] ? buffer_migrate_page (mm/migrate.c:1301)
> [ 3777.828727] compact_zone (mm/compaction.c:1555)
> [ 3777.829290] ? compaction_restarting (mm/compaction.c:1476)
> [ 3777.829969] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
> include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
> [ 3777.830607] compact_zone_order (mm/compaction.c:1653)
> [ 3777.831204] ? kick_process (kernel/sched/core.c:2692)
> [ 3777.831774] ? compact_zone (mm/compaction.c:1637)
> [ 3777.832336] ? io_schedule_timeout (kernel/sched/core.c:3266)
> [ 3777.832934] try_to_compact_pages (mm/compaction.c:1717)
> [ 3777.833550] ? compaction_zonelist_suitable (mm/compaction.c:1679)
> [ 3777.834265] __alloc_pages_direct_compact (mm/page_alloc.c:3180)
> [ 3777.834922] ? get_page_from_freelist (mm/page_alloc.c:3172)
> [ 3777.835549] __alloc_pages_slowpath (mm/page_alloc.c:3741)
> [ 3777.836210] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:84 
> arch/x86/kernel/kvmclock.c:92)
> [ 3777.836744] ? __alloc_pages_direct_compact (mm/page_alloc.c:3546)
> [ 3777.837429] ? get_page_from_freelist (mm/page_alloc.c:2950)
> [ 3777.838072] ? release_pages (mm/swap.c:731)
> [ 3777.838610] ? __isolate_free_page (mm/page_alloc.c:2883)
> [ 3777.839209] ? ___might_sleep (kernel/sched/core.c:7540 (discriminator 1))
> [ 3777.839826] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
> [ 3777.840427] __alloc_pages_nodemask (mm/page_alloc.c:3841)
> [ 3777.841071] ? rwsem_wake (kernel/locking/rwsem-xadd.c:580)
> [ 3777.841608] ? __alloc_pages_slowpath (mm/page_alloc.c:3757)
> [ 3777.842253] ? call_rwsem_wake (arch/x86/lib/rwsem.S:129)
> [ 3777.842839] ? up_write (kernel/locking/rwsem.c:112)
> [ 3777.843350] ? pmdp_huge_clear_flush (mm/pgtable-generic.c:131)
> [ 3777.844125] khugepaged_alloc_page (mm/khugepaged.c:752)
> [ 3777.844719] collapse_huge_page (mm/khugepaged.c:948)
> [

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-13 Thread Joonsoo Kim 
On Mon, Jun 13, 2016 at 04:31:15PM -0400, Sasha Levin wrote:
> On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> > From: Joonsoo Kim 
> > 
> > We don't need to split freepages with holding the zone lock. It will cause
> > more contention on zone lock so not desirable.
> > 
> > Signed-off-by: Joonsoo Kim 
> 
> Hey Joonsoo,

Hello, Sasha.
> 
> I'm seeing the following corruption/crash which seems to be related to
> this patch:

Could you tell me why you think that following corruption is related
to this patch? list_del() in __isolate_free_page() is unchanged part.

Before this patch, we did it by split_free_page() ->
__isolate_free_page() -> list_del(). With this patch, we do it by
calling __isolate_free_page() directly.

Thanks.


> [ 3777.807224] [ cut here ]
> 
> [ 3777.807834] WARNING: CPU: 5 PID: 3270 at lib/list_debug.c:62 
> __list_del_entry+0x14e/0x280
> 
> [ 3777.808562] list_del corruption. next->prev should be ea0004a76120, 
> but was ea0004a72120
> 
> [ 3777.809498] Modules linked in:
> 
> [ 3777.809923] CPU: 5 PID: 3270 Comm: khugepaged Tainted: GW   
> 4.7.0-rc2-next-20160609-sasha-00024-g30ecaf6 #3101
> 
> [ 3777.811014]  1100f9315d7b 0bb7299a 8807c98aec60 
> a0035b2b
> 
> [ 3777.811816]  0005 fbfff5630bf4 41b58ab3 
> aaaf18e0
> 
> [ 3777.812662]  a00359bc 9e54d4a0 a8b2ade0 
> 8807c98aece0
> 
> [ 3777.813493] Call Trace:
> 
> [ 3777.813796] dump_stack (lib/dump_stack.c:53)
> [ 3777.814310] ? arch_local_irq_restore 
> (./arch/x86/include/asm/paravirt.h:134)
> [ 3777.814947] ? is_module_text_address (kernel/module.c:4185)
> [ 3777.815571] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.816174] ? vprintk_default (kernel/printk/printk.c:1886)
> [ 3777.816761] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.817381] __warn (kernel/panic.c:518)
> [ 3777.817867] warn_slowpath_fmt (kernel/panic.c:526)
> [ 3777.818428] ? __warn (kernel/panic.c:526)
> [ 3777.819001] ? __schedule (kernel/sched/core.c:2858 
> kernel/sched/core.c:3345)
> [ 3777.819541] __list_del_entry (lib/list_debug.c:60 (discriminator 1))
> [ 3777.820116] ? __list_add (lib/list_debug.c:45)
> [ 3777.820721] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
> [ 3777.821347] list_del (lib/list_debug.c:78)
> [ 3777.821829] __isolate_free_page (mm/page_alloc.c:2514)
> [ 3777.822400] ? __zone_watermark_ok (mm/page_alloc.c:2493)
> [ 3777.823007] isolate_freepages_block (mm/compaction.c:498)
> [ 3777.823629] ? compact_unlock_should_abort (mm/compaction.c:417)
> [ 3777.824312] compaction_alloc (mm/compaction.c:1112 mm/compaction.c:1156)
> [ 3777.824871] ? isolate_freepages_block (mm/compaction.c:1146)
> [ 3777.825512] ? __page_cache_release (mm/swap.c:73)
> [ 3777.826127] migrate_pages (mm/migrate.c:1079 mm/migrate.c:1325)
> [ 3777.826712] ? __reset_isolation_suitable (mm/compaction.c:1175)
> [ 3777.827398] ? isolate_freepages_block (mm/compaction.c:1146)
> [ 3777.828109] ? buffer_migrate_page (mm/migrate.c:1301)
> [ 3777.828727] compact_zone (mm/compaction.c:1555)
> [ 3777.829290] ? compaction_restarting (mm/compaction.c:1476)
> [ 3777.829969] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
> include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
> [ 3777.830607] compact_zone_order (mm/compaction.c:1653)
> [ 3777.831204] ? kick_process (kernel/sched/core.c:2692)
> [ 3777.831774] ? compact_zone (mm/compaction.c:1637)
> [ 3777.832336] ? io_schedule_timeout (kernel/sched/core.c:3266)
> [ 3777.832934] try_to_compact_pages (mm/compaction.c:1717)
> [ 3777.833550] ? compaction_zonelist_suitable (mm/compaction.c:1679)
> [ 3777.834265] __alloc_pages_direct_compact (mm/page_alloc.c:3180)
> [ 3777.834922] ? get_page_from_freelist (mm/page_alloc.c:3172)
> [ 3777.835549] __alloc_pages_slowpath (mm/page_alloc.c:3741)
> [ 3777.836210] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:84 
> arch/x86/kernel/kvmclock.c:92)
> [ 3777.836744] ? __alloc_pages_direct_compact (mm/page_alloc.c:3546)
> [ 3777.837429] ? get_page_from_freelist (mm/page_alloc.c:2950)
> [ 3777.838072] ? release_pages (mm/swap.c:731)
> [ 3777.838610] ? __isolate_free_page (mm/page_alloc.c:2883)
> [ 3777.839209] ? ___might_sleep (kernel/sched/core.c:7540 (discriminator 1))
> [ 3777.839826] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
> [ 3777.840427] __alloc_pages_nodemask (mm/page_alloc.c:3841)
> [ 3777.841071] ? rwsem_wake (kernel/locking/rwsem-xadd.c:580)
> [ 3777.841608] ? __alloc_pages_slowpath (mm/page_alloc.c:3757)
> [ 3777.842253] ? call_rwsem_wake (arch/x86/lib/rwsem.S:129)
> [ 3777.842839] ? up_write (kernel/locking/rwsem.c:112)
> [ 3777.843350] ? pmdp_huge_clear_flush (mm/pgtable-generic.c:131)
> [ 3777.844125] khugepaged_alloc_page (mm/khugepaged.c:752)
> [ 3777.844719] collapse_huge_page (mm/khugepaged.c:948)
> [ 3777.845332] ? khugepaged_scan_shmem

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-13 Thread Sasha Levin 
On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> From: Joonsoo Kim 
> 
> We don't need to split freepages with holding the zone lock. It will cause
> more contention on zone lock so not desirable.
> 
> Signed-off-by: Joonsoo Kim 

Hey Joonsoo,

I'm seeing the following corruption/crash which seems to be related to
this patch:

[ 3777.807224] [ cut here ]

[ 3777.807834] WARNING: CPU: 5 PID: 3270 at lib/list_debug.c:62 
__list_del_entry+0x14e/0x280

[ 3777.808562] list_del corruption. next->prev should be ea0004a76120, but 
was ea0004a72120

[ 3777.809498] Modules linked in:

[ 3777.809923] CPU: 5 PID: 3270 Comm: khugepaged Tainted: GW   
4.7.0-rc2-next-20160609-sasha-00024-g30ecaf6 #3101

[ 3777.811014]  1100f9315d7b 0bb7299a 8807c98aec60 
a0035b2b

[ 3777.811816]  0005 fbfff5630bf4 41b58ab3 
aaaf18e0

[ 3777.812662]  a00359bc 9e54d4a0 a8b2ade0 
8807c98aece0

[ 3777.813493] Call Trace:

[ 3777.813796] dump_stack (lib/dump_stack.c:53)
[ 3777.814310] ? arch_local_irq_restore (./arch/x86/include/asm/paravirt.h:134)
[ 3777.814947] ? is_module_text_address (kernel/module.c:4185)
[ 3777.815571] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.816174] ? vprintk_default (kernel/printk/printk.c:1886)
[ 3777.816761] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.817381] __warn (kernel/panic.c:518)
[ 3777.817867] warn_slowpath_fmt (kernel/panic.c:526)
[ 3777.818428] ? __warn (kernel/panic.c:526)
[ 3777.819001] ? __schedule (kernel/sched/core.c:2858 kernel/sched/core.c:3345)
[ 3777.819541] __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.820116] ? __list_add (lib/list_debug.c:45)
[ 3777.820721] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
[ 3777.821347] list_del (lib/list_debug.c:78)
[ 3777.821829] __isolate_free_page (mm/page_alloc.c:2514)
[ 3777.822400] ? __zone_watermark_ok (mm/page_alloc.c:2493)
[ 3777.823007] isolate_freepages_block (mm/compaction.c:498)
[ 3777.823629] ? compact_unlock_should_abort (mm/compaction.c:417)
[ 3777.824312] compaction_alloc (mm/compaction.c:1112 mm/compaction.c:1156)
[ 3777.824871] ? isolate_freepages_block (mm/compaction.c:1146)
[ 3777.825512] ? __page_cache_release (mm/swap.c:73)
[ 3777.826127] migrate_pages (mm/migrate.c:1079 mm/migrate.c:1325)
[ 3777.826712] ? __reset_isolation_suitable (mm/compaction.c:1175)
[ 3777.827398] ? isolate_freepages_block (mm/compaction.c:1146)
[ 3777.828109] ? buffer_migrate_page (mm/migrate.c:1301)
[ 3777.828727] compact_zone (mm/compaction.c:1555)
[ 3777.829290] ? compaction_restarting (mm/compaction.c:1476)
[ 3777.829969] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
[ 3777.830607] compact_zone_order (mm/compaction.c:1653)
[ 3777.831204] ? kick_process (kernel/sched/core.c:2692)
[ 3777.831774] ? compact_zone (mm/compaction.c:1637)
[ 3777.832336] ? io_schedule_timeout (kernel/sched/core.c:3266)
[ 3777.832934] try_to_compact_pages (mm/compaction.c:1717)
[ 3777.833550] ? compaction_zonelist_suitable (mm/compaction.c:1679)
[ 3777.834265] __alloc_pages_direct_compact (mm/page_alloc.c:3180)
[ 3777.834922] ? get_page_from_freelist (mm/page_alloc.c:3172)
[ 3777.835549] __alloc_pages_slowpath (mm/page_alloc.c:3741)
[ 3777.836210] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:84 
arch/x86/kernel/kvmclock.c:92)
[ 3777.836744] ? __alloc_pages_direct_compact (mm/page_alloc.c:3546)
[ 3777.837429] ? get_page_from_freelist (mm/page_alloc.c:2950)
[ 3777.838072] ? release_pages (mm/swap.c:731)
[ 3777.838610] ? __isolate_free_page (mm/page_alloc.c:2883)
[ 3777.839209] ? ___might_sleep (kernel/sched/core.c:7540 (discriminator 1))
[ 3777.839826] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
[ 3777.840427] __alloc_pages_nodemask (mm/page_alloc.c:3841)
[ 3777.841071] ? rwsem_wake (kernel/locking/rwsem-xadd.c:580)
[ 3777.841608] ? __alloc_pages_slowpath (mm/page_alloc.c:3757)
[ 3777.842253] ? call_rwsem_wake (arch/x86/lib/rwsem.S:129)
[ 3777.842839] ? up_write (kernel/locking/rwsem.c:112)
[ 3777.843350] ? pmdp_huge_clear_flush (mm/pgtable-generic.c:131)
[ 3777.844125] khugepaged_alloc_page (mm/khugepaged.c:752)
[ 3777.844719] collapse_huge_page (mm/khugepaged.c:948)
[ 3777.845332] ? khugepaged_scan_shmem (mm/khugepaged.c:922)
[ 3777.846020] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
[ 3777.846608] ? remove_wait_queue (kernel/sched/wait.c:292)
[ 3777.847181] khugepaged (mm/khugepaged.c:1724 mm/khugepaged.c:1799 
mm/khugepaged.c:1848)
[ 3777.847704] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
[ 3777.848297] ? collapse_huge_page (mm/khugepaged.c:1840)
[ 3777.848950] ? io_schedule_timeout (kernel/sched/core.c:3266)
[ 3777.849555] ?

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-13 Thread Sasha Levin 
On 05/25/2016 10:37 PM, js1...@gmail.com wrote:
> From: Joonsoo Kim 
> 
> We don't need to split freepages with holding the zone lock. It will cause
> more contention on zone lock so not desirable.
> 
> Signed-off-by: Joonsoo Kim 

Hey Joonsoo,

I'm seeing the following corruption/crash which seems to be related to
this patch:

[ 3777.807224] [ cut here ]

[ 3777.807834] WARNING: CPU: 5 PID: 3270 at lib/list_debug.c:62 
__list_del_entry+0x14e/0x280

[ 3777.808562] list_del corruption. next->prev should be ea0004a76120, but 
was ea0004a72120

[ 3777.809498] Modules linked in:

[ 3777.809923] CPU: 5 PID: 3270 Comm: khugepaged Tainted: GW   
4.7.0-rc2-next-20160609-sasha-00024-g30ecaf6 #3101

[ 3777.811014]  1100f9315d7b 0bb7299a 8807c98aec60 
a0035b2b

[ 3777.811816]  0005 fbfff5630bf4 41b58ab3 
aaaf18e0

[ 3777.812662]  a00359bc 9e54d4a0 a8b2ade0 
8807c98aece0

[ 3777.813493] Call Trace:

[ 3777.813796] dump_stack (lib/dump_stack.c:53)
[ 3777.814310] ? arch_local_irq_restore (./arch/x86/include/asm/paravirt.h:134)
[ 3777.814947] ? is_module_text_address (kernel/module.c:4185)
[ 3777.815571] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.816174] ? vprintk_default (kernel/printk/printk.c:1886)
[ 3777.816761] ? __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.817381] __warn (kernel/panic.c:518)
[ 3777.817867] warn_slowpath_fmt (kernel/panic.c:526)
[ 3777.818428] ? __warn (kernel/panic.c:526)
[ 3777.819001] ? __schedule (kernel/sched/core.c:2858 kernel/sched/core.c:3345)
[ 3777.819541] __list_del_entry (lib/list_debug.c:60 (discriminator 1))
[ 3777.820116] ? __list_add (lib/list_debug.c:45)
[ 3777.820721] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
[ 3777.821347] list_del (lib/list_debug.c:78)
[ 3777.821829] __isolate_free_page (mm/page_alloc.c:2514)
[ 3777.822400] ? __zone_watermark_ok (mm/page_alloc.c:2493)
[ 3777.823007] isolate_freepages_block (mm/compaction.c:498)
[ 3777.823629] ? compact_unlock_should_abort (mm/compaction.c:417)
[ 3777.824312] compaction_alloc (mm/compaction.c:1112 mm/compaction.c:1156)
[ 3777.824871] ? isolate_freepages_block (mm/compaction.c:1146)
[ 3777.825512] ? __page_cache_release (mm/swap.c:73)
[ 3777.826127] migrate_pages (mm/migrate.c:1079 mm/migrate.c:1325)
[ 3777.826712] ? __reset_isolation_suitable (mm/compaction.c:1175)
[ 3777.827398] ? isolate_freepages_block (mm/compaction.c:1146)
[ 3777.828109] ? buffer_migrate_page (mm/migrate.c:1301)
[ 3777.828727] compact_zone (mm/compaction.c:1555)
[ 3777.829290] ? compaction_restarting (mm/compaction.c:1476)
[ 3777.829969] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
[ 3777.830607] compact_zone_order (mm/compaction.c:1653)
[ 3777.831204] ? kick_process (kernel/sched/core.c:2692)
[ 3777.831774] ? compact_zone (mm/compaction.c:1637)
[ 3777.832336] ? io_schedule_timeout (kernel/sched/core.c:3266)
[ 3777.832934] try_to_compact_pages (mm/compaction.c:1717)
[ 3777.833550] ? compaction_zonelist_suitable (mm/compaction.c:1679)
[ 3777.834265] __alloc_pages_direct_compact (mm/page_alloc.c:3180)
[ 3777.834922] ? get_page_from_freelist (mm/page_alloc.c:3172)
[ 3777.835549] __alloc_pages_slowpath (mm/page_alloc.c:3741)
[ 3777.836210] ? kvm_clock_read (./arch/x86/include/asm/preempt.h:84 
arch/x86/kernel/kvmclock.c:92)
[ 3777.836744] ? __alloc_pages_direct_compact (mm/page_alloc.c:3546)
[ 3777.837429] ? get_page_from_freelist (mm/page_alloc.c:2950)
[ 3777.838072] ? release_pages (mm/swap.c:731)
[ 3777.838610] ? __isolate_free_page (mm/page_alloc.c:2883)
[ 3777.839209] ? ___might_sleep (kernel/sched/core.c:7540 (discriminator 1))
[ 3777.839826] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
[ 3777.840427] __alloc_pages_nodemask (mm/page_alloc.c:3841)
[ 3777.841071] ? rwsem_wake (kernel/locking/rwsem-xadd.c:580)
[ 3777.841608] ? __alloc_pages_slowpath (mm/page_alloc.c:3757)
[ 3777.842253] ? call_rwsem_wake (arch/x86/lib/rwsem.S:129)
[ 3777.842839] ? up_write (kernel/locking/rwsem.c:112)
[ 3777.843350] ? pmdp_huge_clear_flush (mm/pgtable-generic.c:131)
[ 3777.844125] khugepaged_alloc_page (mm/khugepaged.c:752)
[ 3777.844719] collapse_huge_page (mm/khugepaged.c:948)
[ 3777.845332] ? khugepaged_scan_shmem (mm/khugepaged.c:922)
[ 3777.846020] ? __might_sleep (kernel/sched/core.c:7532 (discriminator 14))
[ 3777.846608] ? remove_wait_queue (kernel/sched/wait.c:292)
[ 3777.847181] khugepaged (mm/khugepaged.c:1724 mm/khugepaged.c:1799 
mm/khugepaged.c:1848)
[ 3777.847704] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:92 
include/linux/spinlock_api_smp.h:171 kernel/locking/spinlock.c:199)
[ 3777.848297] ? collapse_huge_page (mm/khugepaged.c:1840)
[ 3777.848950] ? io_schedule_timeout (kernel/sched/core.c:3266)
[ 3777.849555] ? default_wake_function (kernel/sched/core.c:3544)
[

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-06 Thread Vlastimil Babka 

On 06/03/2016 02:45 PM, Joonsoo Kim wrote:

2016-06-03 19:10 GMT+09:00 Vlastimil Babka :

On 05/26/2016 04:37 AM, js1...@gmail.com wrote:


From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 



So it wasn't possible to at least move this code from compaction.c to
page_alloc.c? Or better, reuse prep_new_page() with some forged
gfp/alloc_flags? As we discussed in v1...


Sorry for not mentioning that I did it as a separate patch,
Please see below link which is the last one within this patchset.

Link: 
http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo@lge.com


Ah I see. In that case,

Acked-by: Vlastimil Babka 



Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-06 Thread Vlastimil Babka 

On 06/03/2016 02:45 PM, Joonsoo Kim wrote:

2016-06-03 19:10 GMT+09:00 Vlastimil Babka :

On 05/26/2016 04:37 AM, js1...@gmail.com wrote:


From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 



So it wasn't possible to at least move this code from compaction.c to
page_alloc.c? Or better, reuse prep_new_page() with some forged
gfp/alloc_flags? As we discussed in v1...


Sorry for not mentioning that I did it as a separate patch,
Please see below link which is the last one within this patchset.

Link: 
http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo@lge.com


Ah I see. In that case,

Acked-by: Vlastimil Babka 



Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-03 Thread Joonsoo Kim 
2016-06-03 19:10 GMT+09:00 Vlastimil Babka :
> On 05/26/2016 04:37 AM, js1...@gmail.com wrote:
>>
>> From: Joonsoo Kim 
>>
>> We don't need to split freepages with holding the zone lock. It will cause
>> more contention on zone lock so not desirable.
>>
>> Signed-off-by: Joonsoo Kim 
>
>
> So it wasn't possible to at least move this code from compaction.c to
> page_alloc.c? Or better, reuse prep_new_page() with some forged
> gfp/alloc_flags? As we discussed in v1...

Sorry for not mentioning that I did it as a separate patch,
Please see below link which is the last one within this patchset.

Link: 
http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo@lge.com

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-03 Thread Joonsoo Kim 
2016-06-03 19:10 GMT+09:00 Vlastimil Babka :
> On 05/26/2016 04:37 AM, js1...@gmail.com wrote:
>>
>> From: Joonsoo Kim 
>>
>> We don't need to split freepages with holding the zone lock. It will cause
>> more contention on zone lock so not desirable.
>>
>> Signed-off-by: Joonsoo Kim 
>
>
> So it wasn't possible to at least move this code from compaction.c to
> page_alloc.c? Or better, reuse prep_new_page() with some forged
> gfp/alloc_flags? As we discussed in v1...

Sorry for not mentioning that I did it as a separate patch,
Please see below link which is the last one within this patchset.

Link: 
http://lkml.kernel.org/r/1464230275-25791-7-git-send-email-iamjoonsoo@lge.com

Thanks.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-03 Thread Vlastimil Babka 

On 05/26/2016 04:37 AM, js1...@gmail.com wrote:

From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 


So it wasn't possible to at least move this code from compaction.c to 
page_alloc.c? Or better, reuse prep_new_page() with some forged gfp/alloc_flags? 
As we discussed in v1...



---
 include/linux/mm.h |  1 -
 mm/compaction.c| 42 ++
 mm/page_alloc.c| 27 ---
 3 files changed, 30 insertions(+), 40 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a00ec81..1a1782c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -537,7 +537,6 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);

 void split_page(struct page *page, unsigned int order);
-int split_free_page(struct page *page);

 /*
  * Compound pages have a destructor function.  Provide a
diff --git a/mm/compaction.c b/mm/compaction.c
index 1427366..8e013eb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -65,13 +65,31 @@ static unsigned long release_freepages(struct list_head 
*freelist)

 static void map_pages(struct list_head *list)
 {
-   struct page *page;
+   unsigned int i, order, nr_pages;
+   struct page *page, *next;
+   LIST_HEAD(tmp_list);
+
+   list_for_each_entry_safe(page, next, list, lru) {
+   list_del(>lru);
+
+   order = page_private(page);
+   nr_pages = 1 << order;
+   set_page_private(page, 0);
+   set_page_refcounted(page);
+
+   arch_alloc_page(page, order);
+   kernel_map_pages(page, nr_pages, 1);
+   kasan_alloc_pages(page, order);
+   if (order)
+   split_page(page, order);

-   list_for_each_entry(page, list, lru) {
-   arch_alloc_page(page, 0);
-   kernel_map_pages(page, 1, 1);
-   kasan_alloc_pages(page, 0);
+   for (i = 0; i < nr_pages; i++) {
+   list_add(>lru, _list);
+   page++;
+   }
}
+
+   list_splice(_list, list);
 }

 static inline bool migrate_async_suitable(int migratetype)
@@ -368,12 +386,13 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+   unsigned int order;

cursor = pfn_to_page(blockpfn);

/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
-   int isolated, i;
+   int isolated;
struct page *page = cursor;

/*
@@ -439,13 +458,12 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
goto isolate_fail;
}

-   /* Found a free page, break it into order-0 pages */
-   isolated = split_free_page(page);
+   /* Found a free page, will break it into order-0 pages */
+   order = page_order(page);
+   isolated = __isolate_free_page(page, page_order(page));
+   set_page_private(page, order);
total_isolated += isolated;
-   for (i = 0; i < isolated; i++) {
-   list_add(>lru, freelist);
-   page++;
-   }
+   list_add_tail(>lru, freelist);

/* If a page was split, advance to the end of it */
if (isolated) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d27e8b9..5134f46 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2525,33 +2525,6 @@ int __isolate_free_page(struct page *page, unsigned int 
order)
 }

 /*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
- */
-int split_free_page(struct page *page)
-{
-   unsigned int order;
-   int nr_pages;
-
-   order = page_order(page);
-
-   nr_pages = __isolate_free_page(page, order);
-   if (!nr_pages)
-   return 0;
-
-   /* Split into individual pages */
-   set_page_refcounted(page);
-   split_page(page, order);
-   return nr_pages;
-}
-
-/*
  * Update NUMA hit/miss statistics
  *
  * Must be called with interrupts disabled.

Re: [PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-06-03 Thread Vlastimil Babka 

On 05/26/2016 04:37 AM, js1...@gmail.com wrote:

From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 


So it wasn't possible to at least move this code from compaction.c to 
page_alloc.c? Or better, reuse prep_new_page() with some forged gfp/alloc_flags? 
As we discussed in v1...



---
 include/linux/mm.h |  1 -
 mm/compaction.c| 42 ++
 mm/page_alloc.c| 27 ---
 3 files changed, 30 insertions(+), 40 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a00ec81..1a1782c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -537,7 +537,6 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);

 void split_page(struct page *page, unsigned int order);
-int split_free_page(struct page *page);

 /*
  * Compound pages have a destructor function.  Provide a
diff --git a/mm/compaction.c b/mm/compaction.c
index 1427366..8e013eb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -65,13 +65,31 @@ static unsigned long release_freepages(struct list_head 
*freelist)

 static void map_pages(struct list_head *list)
 {
-   struct page *page;
+   unsigned int i, order, nr_pages;
+   struct page *page, *next;
+   LIST_HEAD(tmp_list);
+
+   list_for_each_entry_safe(page, next, list, lru) {
+   list_del(>lru);
+
+   order = page_private(page);
+   nr_pages = 1 << order;
+   set_page_private(page, 0);
+   set_page_refcounted(page);
+
+   arch_alloc_page(page, order);
+   kernel_map_pages(page, nr_pages, 1);
+   kasan_alloc_pages(page, order);
+   if (order)
+   split_page(page, order);

-   list_for_each_entry(page, list, lru) {
-   arch_alloc_page(page, 0);
-   kernel_map_pages(page, 1, 1);
-   kasan_alloc_pages(page, 0);
+   for (i = 0; i < nr_pages; i++) {
+   list_add(>lru, _list);
+   page++;
+   }
}
+
+   list_splice(_list, list);
 }

 static inline bool migrate_async_suitable(int migratetype)
@@ -368,12 +386,13 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+   unsigned int order;

cursor = pfn_to_page(blockpfn);

/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
-   int isolated, i;
+   int isolated;
struct page *page = cursor;

/*
@@ -439,13 +458,12 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
goto isolate_fail;
}

-   /* Found a free page, break it into order-0 pages */
-   isolated = split_free_page(page);
+   /* Found a free page, will break it into order-0 pages */
+   order = page_order(page);
+   isolated = __isolate_free_page(page, page_order(page));
+   set_page_private(page, order);
total_isolated += isolated;
-   for (i = 0; i < isolated; i++) {
-   list_add(>lru, freelist);
-   page++;
-   }
+   list_add_tail(>lru, freelist);

/* If a page was split, advance to the end of it */
if (isolated) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d27e8b9..5134f46 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2525,33 +2525,6 @@ int __isolate_free_page(struct page *page, unsigned int 
order)
 }

 /*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
- */
-int split_free_page(struct page *page)
-{
-   unsigned int order;
-   int nr_pages;
-
-   order = page_order(page);
-
-   nr_pages = __isolate_free_page(page, order);
-   if (!nr_pages)
-   return 0;
-
-   /* Split into individual pages */
-   set_page_refcounted(page);
-   split_page(page, order);
-   return nr_pages;
-}
-
-/*
  * Update NUMA hit/miss statistics
  *
  * Must be called with interrupts disabled.

[PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-05-25 Thread js1304 
From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 
---
 include/linux/mm.h |  1 -
 mm/compaction.c| 42 ++
 mm/page_alloc.c| 27 ---
 3 files changed, 30 insertions(+), 40 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a00ec81..1a1782c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -537,7 +537,6 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
-int split_free_page(struct page *page);
 
 /*
  * Compound pages have a destructor function.  Provide a
diff --git a/mm/compaction.c b/mm/compaction.c
index 1427366..8e013eb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -65,13 +65,31 @@ static unsigned long release_freepages(struct list_head 
*freelist)
 
 static void map_pages(struct list_head *list)
 {
-   struct page *page;
+   unsigned int i, order, nr_pages;
+   struct page *page, *next;
+   LIST_HEAD(tmp_list);
+
+   list_for_each_entry_safe(page, next, list, lru) {
+   list_del(>lru);
+
+   order = page_private(page);
+   nr_pages = 1 << order;
+   set_page_private(page, 0);
+   set_page_refcounted(page);
+
+   arch_alloc_page(page, order);
+   kernel_map_pages(page, nr_pages, 1);
+   kasan_alloc_pages(page, order);
+   if (order)
+   split_page(page, order);
 
-   list_for_each_entry(page, list, lru) {
-   arch_alloc_page(page, 0);
-   kernel_map_pages(page, 1, 1);
-   kasan_alloc_pages(page, 0);
+   for (i = 0; i < nr_pages; i++) {
+   list_add(>lru, _list);
+   page++;
+   }
}
+
+   list_splice(_list, list);
 }
 
 static inline bool migrate_async_suitable(int migratetype)
@@ -368,12 +386,13 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+   unsigned int order;
 
cursor = pfn_to_page(blockpfn);
 
/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
-   int isolated, i;
+   int isolated;
struct page *page = cursor;
 
/*
@@ -439,13 +458,12 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
goto isolate_fail;
}
 
-   /* Found a free page, break it into order-0 pages */
-   isolated = split_free_page(page);
+   /* Found a free page, will break it into order-0 pages */
+   order = page_order(page);
+   isolated = __isolate_free_page(page, page_order(page));
+   set_page_private(page, order);
total_isolated += isolated;
-   for (i = 0; i < isolated; i++) {
-   list_add(>lru, freelist);
-   page++;
-   }
+   list_add_tail(>lru, freelist);
 
/* If a page was split, advance to the end of it */
if (isolated) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d27e8b9..5134f46 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2525,33 +2525,6 @@ int __isolate_free_page(struct page *page, unsigned int 
order)
 }
 
 /*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
- */
-int split_free_page(struct page *page)
-{
-   unsigned int order;
-   int nr_pages;
-
-   order = page_order(page);
-
-   nr_pages = __isolate_free_page(page, order);
-   if (!nr_pages)
-   return 0;
-
-   /* Split into individual pages */
-   set_page_refcounted(page);
-   split_page(page, order);
-   return nr_pages;
-}
-
-/*
  * Update NUMA hit/miss statistics
  *
  * Must be called with interrupts disabled.
-- 
1.9.1

[PATCH v2 1/7] mm/compaction: split freepages without holding the zone lock

2016-05-25 Thread js1304 
From: Joonsoo Kim 

We don't need to split freepages with holding the zone lock. It will cause
more contention on zone lock so not desirable.

Signed-off-by: Joonsoo Kim 
---
 include/linux/mm.h |  1 -
 mm/compaction.c| 42 ++
 mm/page_alloc.c| 27 ---
 3 files changed, 30 insertions(+), 40 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a00ec81..1a1782c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -537,7 +537,6 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
-int split_free_page(struct page *page);
 
 /*
  * Compound pages have a destructor function.  Provide a
diff --git a/mm/compaction.c b/mm/compaction.c
index 1427366..8e013eb 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -65,13 +65,31 @@ static unsigned long release_freepages(struct list_head 
*freelist)
 
 static void map_pages(struct list_head *list)
 {
-   struct page *page;
+   unsigned int i, order, nr_pages;
+   struct page *page, *next;
+   LIST_HEAD(tmp_list);
+
+   list_for_each_entry_safe(page, next, list, lru) {
+   list_del(>lru);
+
+   order = page_private(page);
+   nr_pages = 1 << order;
+   set_page_private(page, 0);
+   set_page_refcounted(page);
+
+   arch_alloc_page(page, order);
+   kernel_map_pages(page, nr_pages, 1);
+   kasan_alloc_pages(page, order);
+   if (order)
+   split_page(page, order);
 
-   list_for_each_entry(page, list, lru) {
-   arch_alloc_page(page, 0);
-   kernel_map_pages(page, 1, 1);
-   kasan_alloc_pages(page, 0);
+   for (i = 0; i < nr_pages; i++) {
+   list_add(>lru, _list);
+   page++;
+   }
}
+
+   list_splice(_list, list);
 }
 
 static inline bool migrate_async_suitable(int migratetype)
@@ -368,12 +386,13 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+   unsigned int order;
 
cursor = pfn_to_page(blockpfn);
 
/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
-   int isolated, i;
+   int isolated;
struct page *page = cursor;
 
/*
@@ -439,13 +458,12 @@ static unsigned long isolate_freepages_block(struct 
compact_control *cc,
goto isolate_fail;
}
 
-   /* Found a free page, break it into order-0 pages */
-   isolated = split_free_page(page);
+   /* Found a free page, will break it into order-0 pages */
+   order = page_order(page);
+   isolated = __isolate_free_page(page, page_order(page));
+   set_page_private(page, order);
total_isolated += isolated;
-   for (i = 0; i < isolated; i++) {
-   list_add(>lru, freelist);
-   page++;
-   }
+   list_add_tail(>lru, freelist);
 
/* If a page was split, advance to the end of it */
if (isolated) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d27e8b9..5134f46 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2525,33 +2525,6 @@ int __isolate_free_page(struct page *page, unsigned int 
order)
 }
 
 /*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
- */
-int split_free_page(struct page *page)
-{
-   unsigned int order;
-   int nr_pages;
-
-   order = page_order(page);
-
-   nr_pages = __isolate_free_page(page, order);
-   if (!nr_pages)
-   return 0;
-
-   /* Split into individual pages */
-   set_page_refcounted(page);
-   split_page(page, order);
-   return nr_pages;
-}
-
-/*
  * Update NUMA hit/miss statistics
  *
  * Must be called with interrupts disabled.
-- 
1.9.1