Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Kirill Tkhai
On 08.08.2018 15:36, Tetsuo Handa wrote: > On 2018/08/08 20:51, Kirill Tkhai wrote: >> @@ -192,7 +193,6 @@ static int prealloc_memcg_shrinker(struct shrinker >> *shrinker) >> int id, ret = -ENOMEM; >> >> down_write(_rwsem); >> -/* This may call shrinker, so it must use

Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Kirill Tkhai
On 08.08.2018 15:36, Tetsuo Handa wrote: > On 2018/08/08 20:51, Kirill Tkhai wrote: >> @@ -192,7 +193,6 @@ static int prealloc_memcg_shrinker(struct shrinker >> *shrinker) >> int id, ret = -ENOMEM; >> >> down_write(_rwsem); >> -/* This may call shrinker, so it must use

Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Tetsuo Handa
On 2018/08/08 20:51, Kirill Tkhai wrote: > @@ -192,7 +193,6 @@ static int prealloc_memcg_shrinker(struct shrinker > *shrinker) > int id, ret = -ENOMEM; > > down_write(_rwsem); > - /* This may call shrinker, so it must use down_read_trylock() */ > id = idr_alloc(_idr,

Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Tetsuo Handa
On 2018/08/08 20:51, Kirill Tkhai wrote: > @@ -192,7 +193,6 @@ static int prealloc_memcg_shrinker(struct shrinker > *shrinker) > int id, ret = -ENOMEM; > > down_write(_rwsem); > - /* This may call shrinker, so it must use down_read_trylock() */ > id = idr_alloc(_idr,

Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Kirill Tkhai
This also requires call_srcu() in memcg_expand_one_shrinker_map() and srcu_dereference() in shrink_slab_memcg(). The updated patch is below: [PATCH] mm: Make shrink_slab() lockless From: Kirill Tkhai The patch makes shrinker list and shrinker_idr SRCU-safe for readers. This requires

Re: [PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-08 Thread Kirill Tkhai
This also requires call_srcu() in memcg_expand_one_shrinker_map() and srcu_dereference() in shrink_slab_memcg(). The updated patch is below: [PATCH] mm: Make shrink_slab() lockless From: Kirill Tkhai The patch makes shrinker list and shrinker_idr SRCU-safe for readers. This requires

[PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-07 Thread Kirill Tkhai
The patch makes shrinker list and shrinker_idr SRCU-safe for readers. This requires synchronize_srcu() on finalize stage unregistering stage, which waits till all parallel shrink_slab() are finished Note, that patch removes rwsem_is_contended() checks from the code, and this does not result in

[PATCH RFC 02/10] mm: Make shrink_slab() lockless

2018-08-07 Thread Kirill Tkhai
The patch makes shrinker list and shrinker_idr SRCU-safe for readers. This requires synchronize_srcu() on finalize stage unregistering stage, which waits till all parallel shrink_slab() are finished Note, that patch removes rwsem_is_contended() checks from the code, and this does not result in