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[PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().

Kanchana P Sridhar posted 8 patches 2 months ago
There is a newer version of this series
[PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Kanchana P Sridhar 2 months ago 
Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
to be representative of the call it makes to percpu_ref_tryget().
A subsequent patch will introduce a new zswap_pool_get() that calls
percpu_ref_get().

The intent behind this change is for higher level zswap API such as
zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
refcount is "0" (which means it could be getting destroyed) and to handle
this as an error condition. zswap_store() would proceed only if
zswap_pool_tryget() returns success, and any additional pool refcounts that
need to be obtained for compressing sub-pages in a large folio could simply
call zswap_pool_get().

Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
---
 mm/zswap.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index fd7a8c14457a..0f281e50a034 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -403,7 +403,7 @@ static void __zswap_pool_empty(struct percpu_ref *ref)
 	spin_unlock_bh(&zswap_pools_lock);
 }
 
-static int __must_check zswap_pool_get(struct zswap_pool *pool)
+static int __must_check zswap_pool_tryget(struct zswap_pool *pool)
 {
 	if (!pool)
 		return 0;
@@ -441,7 +441,7 @@ static struct zswap_pool *zswap_pool_current_get(void)
 	rcu_read_lock();
 
 	pool = __zswap_pool_current();
-	if (!zswap_pool_get(pool))
+	if (!zswap_pool_tryget(pool))
 		pool = NULL;
 
 	rcu_read_unlock();
@@ -462,7 +462,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
 		if (strcmp(zpool_get_type(pool->zpool), type))
 			continue;
 		/* if we can't get it, it's about to be destroyed */
-		if (!zswap_pool_get(pool))
+		if (!zswap_pool_tryget(pool))
 			continue;
 		return pool;
 	}
-- 
2.27.0
Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Nhat Pham 2 months ago 
On Fri, Sep 27, 2024 at 7:16 PM Kanchana P Sridhar
<kanchana.p.sridhar@intel.com> wrote:
>
> Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> to be representative of the call it makes to percpu_ref_tryget().
> A subsequent patch will introduce a new zswap_pool_get() that calls
> percpu_ref_get().
>
> The intent behind this change is for higher level zswap API such as
> zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> refcount is "0" (which means it could be getting destroyed) and to handle
> this as an error condition. zswap_store() would proceed only if
> zswap_pool_tryget() returns success, and any additional pool refcounts that
> need to be obtained for compressing sub-pages in a large folio could simply
> call zswap_pool_get().
>
> Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>

Reviewed-by: Nhat Pham <nphamcs@gmail.com>
RE: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Sridhar, Kanchana P 1 month, 4 weeks ago 
> -----Original Message-----
> From: Nhat Pham <nphamcs@gmail.com>
> Sent: Saturday, September 28, 2024 4:27 PM
> To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org;
> hannes@cmpxchg.org; yosryahmed@google.com;
> chengming.zhou@linux.dev; usamaarif642@gmail.com;
> shakeel.butt@linux.dev; ryan.roberts@arm.com; Huang, Ying
> <ying.huang@intel.com>; 21cnbao@gmail.com; akpm@linux-foundation.org;
> Zou, Nanhai <nanhai.zou@intel.com>; Feghali, Wajdi K
> <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>
> Subject: Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to
> zswap_pool_tryget().
> 
> On Fri, Sep 27, 2024 at 7:16 PM Kanchana P Sridhar
> <kanchana.p.sridhar@intel.com> wrote:
> >
> > Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> > to be representative of the call it makes to percpu_ref_tryget().
> > A subsequent patch will introduce a new zswap_pool_get() that calls
> > percpu_ref_get().
> >
> > The intent behind this change is for higher level zswap API such as
> > zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> > refcount is "0" (which means it could be getting destroyed) and to handle
> > this as an error condition. zswap_store() would proceed only if
> > zswap_pool_tryget() returns success, and any additional pool refcounts that
> > need to be obtained for compressing sub-pages in a large folio could simply
> > call zswap_pool_get().
> >
> > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
> 
> Reviewed-by: Nhat Pham <nphamcs@gmail.com>

Thanks Nhat! 

Thanks,
Kanchana
Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Johannes Weiner 2 months ago 
On Fri, Sep 27, 2024 at 07:16:15PM -0700, Kanchana P Sridhar wrote:
> Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> to be representative of the call it makes to percpu_ref_tryget().
> A subsequent patch will introduce a new zswap_pool_get() that calls
> percpu_ref_get().
> 
> The intent behind this change is for higher level zswap API such as
> zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> refcount is "0" (which means it could be getting destroyed) and to handle
> this as an error condition. zswap_store() would proceed only if
> zswap_pool_tryget() returns success, and any additional pool refcounts that
> need to be obtained for compressing sub-pages in a large folio could simply
> call zswap_pool_get().
> 
> Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Chengming Zhou 2 months ago 
On 2024/9/28 10:16, Kanchana P Sridhar wrote:
> Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> to be representative of the call it makes to percpu_ref_tryget().
> A subsequent patch will introduce a new zswap_pool_get() that calls
> percpu_ref_get().
> 
> The intent behind this change is for higher level zswap API such as
> zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> refcount is "0" (which means it could be getting destroyed) and to handle
> this as an error condition. zswap_store() would proceed only if
> zswap_pool_tryget() returns success, and any additional pool refcounts that
> need to be obtained for compressing sub-pages in a large folio could simply
> call zswap_pool_get().
> 
> Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>

Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>

> ---
>   mm/zswap.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/zswap.c b/mm/zswap.c
> index fd7a8c14457a..0f281e50a034 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -403,7 +403,7 @@ static void __zswap_pool_empty(struct percpu_ref *ref)
>   	spin_unlock_bh(&zswap_pools_lock);
>   }
>   
> -static int __must_check zswap_pool_get(struct zswap_pool *pool)
> +static int __must_check zswap_pool_tryget(struct zswap_pool *pool)
>   {
>   	if (!pool)
>   		return 0;
> @@ -441,7 +441,7 @@ static struct zswap_pool *zswap_pool_current_get(void)
>   	rcu_read_lock();
>   
>   	pool = __zswap_pool_current();
> -	if (!zswap_pool_get(pool))
> +	if (!zswap_pool_tryget(pool))
>   		pool = NULL;
>   
>   	rcu_read_unlock();
> @@ -462,7 +462,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
>   		if (strcmp(zpool_get_type(pool->zpool), type))
>   			continue;
>   		/* if we can't get it, it's about to be destroyed */
> -		if (!zswap_pool_get(pool))
> +		if (!zswap_pool_tryget(pool))
>   			continue;
>   		return pool;
>   	}
RE: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Sridhar, Kanchana P 1 month, 4 weeks ago 
> -----Original Message-----
> From: Chengming Zhou <chengming.zhou@linux.dev>
> Sent: Friday, September 27, 2024 10:44 PM
> To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>; linux-
> kernel@vger.kernel.org; linux-mm@kvack.org; hannes@cmpxchg.org;
> yosryahmed@google.com; nphamcs@gmail.com; usamaarif642@gmail.com;
> shakeel.butt@linux.dev; ryan.roberts@arm.com; Huang, Ying
> <ying.huang@intel.com>; 21cnbao@gmail.com; akpm@linux-foundation.org
> Cc: Zou, Nanhai <nanhai.zou@intel.com>; Feghali, Wajdi K
> <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>
> Subject: Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to
> zswap_pool_tryget().
> 
> On 2024/9/28 10:16, Kanchana P Sridhar wrote:
> > Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> > to be representative of the call it makes to percpu_ref_tryget().
> > A subsequent patch will introduce a new zswap_pool_get() that calls
> > percpu_ref_get().
> >
> > The intent behind this change is for higher level zswap API such as
> > zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> > refcount is "0" (which means it could be getting destroyed) and to handle
> > this as an error condition. zswap_store() would proceed only if
> > zswap_pool_tryget() returns success, and any additional pool refcounts that
> > need to be obtained for compressing sub-pages in a large folio could simply
> > call zswap_pool_get().
> >
> > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
> 
> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>

Thanks Chengming!

Thanks,
Kanchana

> 
> > ---
> >   mm/zswap.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/mm/zswap.c b/mm/zswap.c
> > index fd7a8c14457a..0f281e50a034 100644
> > --- a/mm/zswap.c
> > +++ b/mm/zswap.c
> > @@ -403,7 +403,7 @@ static void __zswap_pool_empty(struct percpu_ref
> *ref)
> >   	spin_unlock_bh(&zswap_pools_lock);
> >   }
> >
> > -static int __must_check zswap_pool_get(struct zswap_pool *pool)
> > +static int __must_check zswap_pool_tryget(struct zswap_pool *pool)
> >   {
> >   	if (!pool)
> >   		return 0;
> > @@ -441,7 +441,7 @@ static struct zswap_pool
> *zswap_pool_current_get(void)
> >   	rcu_read_lock();
> >
> >   	pool = __zswap_pool_current();
> > -	if (!zswap_pool_get(pool))
> > +	if (!zswap_pool_tryget(pool))
> >   		pool = NULL;
> >
> >   	rcu_read_unlock();
> > @@ -462,7 +462,7 @@ static struct zswap_pool
> *zswap_pool_find_get(char *type, char *compressor)
> >   		if (strcmp(zpool_get_type(pool->zpool), type))
> >   			continue;
> >   		/* if we can't get it, it's about to be destroyed */
> > -		if (!zswap_pool_get(pool))
> > +		if (!zswap_pool_tryget(pool))
> >   			continue;
> >   		return pool;
> >   	}
Re: [PATCH v8 3/8] mm: zswap: Rename zswap_pool_get() to zswap_pool_tryget().
Posted by Yosry Ahmed 2 months ago 
On Fri, Sep 27, 2024 at 7:16 PM Kanchana P Sridhar
<kanchana.p.sridhar@intel.com> wrote:
>
> Modify the name of the existing zswap_pool_get() to zswap_pool_tryget()
> to be representative of the call it makes to percpu_ref_tryget().
> A subsequent patch will introduce a new zswap_pool_get() that calls
> percpu_ref_get().
>
> The intent behind this change is for higher level zswap API such as
> zswap_store() to call zswap_pool_tryget() to check upfront if the pool's
> refcount is "0" (which means it could be getting destroyed) and to handle
> this as an error condition. zswap_store() would proceed only if
> zswap_pool_tryget() returns success, and any additional pool refcounts that
> need to be obtained for compressing sub-pages in a large folio could simply
> call zswap_pool_get().
>
> Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>

Acked-by: Yosry Ahmed <yosryahmed@google.com>

> ---
>  mm/zswap.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index fd7a8c14457a..0f281e50a034 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -403,7 +403,7 @@ static void __zswap_pool_empty(struct percpu_ref *ref)
>         spin_unlock_bh(&zswap_pools_lock);
>  }
>
> -static int __must_check zswap_pool_get(struct zswap_pool *pool)
> +static int __must_check zswap_pool_tryget(struct zswap_pool *pool)
>  {
>         if (!pool)
>                 return 0;
> @@ -441,7 +441,7 @@ static struct zswap_pool *zswap_pool_current_get(void)
>         rcu_read_lock();
>
>         pool = __zswap_pool_current();
> -       if (!zswap_pool_get(pool))
> +       if (!zswap_pool_tryget(pool))
>                 pool = NULL;
>
>         rcu_read_unlock();
> @@ -462,7 +462,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
>                 if (strcmp(zpool_get_type(pool->zpool), type))
>                         continue;
>                 /* if we can't get it, it's about to be destroyed */
> -               if (!zswap_pool_get(pool))
> +               if (!zswap_pool_tryget(pool))
>                         continue;
>                 return pool;
>         }
> --
> 2.27.0
>

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