Re: [PATCH v2 1/1] vhost scsi: alloc vhost_scsi with kvzalloc() to avoid delay

2021-02-01 Thread Joe Jin 
Can anyone help to review this patch and give a review-by for it please?

Thanks,
Joe
On 1/24/21 7:12 PM, Jason Wang wrote:
>
> On 2021/1/23 下午4:08, Dongli Zhang wrote:
>> The size of 'struct vhost_scsi' is order-10 (~2.3MB). It may take long time
>> delay by kzalloc() to compact memory pages by retrying multiple times when
>> there is a lack of high-order pages. As a result, there is latency to
>> create a VM (with vhost-scsi) or to hotadd vhost-scsi-based storage.
>>
>> The prior commit 595cb754983d ("vhost/scsi: use vmalloc for order-10
>> allocation") prefers to fallback only when really needed, while this patch
>> allocates with kvzalloc() with __GFP_NORETRY implicitly set to avoid
>> retrying memory pages compact for multiple times.
>>
>> The __GFP_NORETRY is implicitly set if the size to allocate is more than
>> PAGE_SZIE and when __GFP_RETRY_MAYFAIL is not explicitly set.
>>
>> Cc: Aruna Ramakrishna 
>> Cc: Joe Jin 
>> Signed-off-by: Dongli Zhang 
>> ---
>> Changed since v1:
>>    - To combine kzalloc() and vzalloc() as kvzalloc()
>>  (suggested by Jason Wang)
>>
>>   drivers/vhost/scsi.c | 9 +++--
>>   1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
>> index 4ce9f00ae10e..5de21ad4bd05 100644
>> --- a/drivers/vhost/scsi.c
>> +++ b/drivers/vhost/scsi.c
>> @@ -1814,12 +1814,9 @@ static int vhost_scsi_open(struct inode *inode, 
>> struct file *f)
>>   struct vhost_virtqueue **vqs;
>>   int r = -ENOMEM, i;
>>   -    vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | 
>> __GFP_RETRY_MAYFAIL);
>> -    if (!vs) {
>> -    vs = vzalloc(sizeof(*vs));
>> -    if (!vs)
>> -    goto err_vs;
>> -    }
>> +    vs = kvzalloc(sizeof(*vs), GFP_KERNEL);
>> +    if (!vs)
>> +    goto err_vs;
>>     vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);
>>   if (!vqs)
>
>
> Acked-by: Jason Wang 
>
>
>

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Re: [PATCH v2 1/1] vhost scsi: alloc vhost_scsi with kvzalloc() to avoid delay

2021-01-24 Thread Jason Wang 


On 2021/1/23 下午4:08, Dongli Zhang wrote:

The size of 'struct vhost_scsi' is order-10 (~2.3MB). It may take long time
delay by kzalloc() to compact memory pages by retrying multiple times when
there is a lack of high-order pages. As a result, there is latency to
create a VM (with vhost-scsi) or to hotadd vhost-scsi-based storage.

The prior commit 595cb754983d ("vhost/scsi: use vmalloc for order-10
allocation") prefers to fallback only when really needed, while this patch
allocates with kvzalloc() with __GFP_NORETRY implicitly set to avoid
retrying memory pages compact for multiple times.

The __GFP_NORETRY is implicitly set if the size to allocate is more than
PAGE_SZIE and when __GFP_RETRY_MAYFAIL is not explicitly set.

Cc: Aruna Ramakrishna 
Cc: Joe Jin 
Signed-off-by: Dongli Zhang 
---
Changed since v1:
   - To combine kzalloc() and vzalloc() as kvzalloc()
 (suggested by Jason Wang)

  drivers/vhost/scsi.c | 9 +++--
  1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 4ce9f00ae10e..5de21ad4bd05 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1814,12 +1814,9 @@ static int vhost_scsi_open(struct inode *inode, struct 
file *f)
struct vhost_virtqueue **vqs;
int r = -ENOMEM, i;
  
-	vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);

-   if (!vs) {
-   vs = vzalloc(sizeof(*vs));
-   if (!vs)
-   goto err_vs;
-   }
+   vs = kvzalloc(sizeof(*vs), GFP_KERNEL);
+   if (!vs)
+   goto err_vs;
  
  	vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);

if (!vqs)



Acked-by: Jason Wang 



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Re: [PATCH v2 1/1] vhost scsi: alloc vhost_scsi with kvzalloc() to avoid delay

2021-01-23 Thread Dongli Zhang 
According to my "git send-email" history, I have CCed jasow...@redhat.com. Not
sure why Jason is not on the list.

CCed Jason. Thank you very much!

Dongli Zhang

On 1/23/21 12:08 AM, Dongli Zhang wrote:
> The size of 'struct vhost_scsi' is order-10 (~2.3MB). It may take long time
> delay by kzalloc() to compact memory pages by retrying multiple times when
> there is a lack of high-order pages. As a result, there is latency to
> create a VM (with vhost-scsi) or to hotadd vhost-scsi-based storage.
> 
> The prior commit 595cb754983d ("vhost/scsi: use vmalloc for order-10
> allocation") prefers to fallback only when really needed, while this patch
> allocates with kvzalloc() with __GFP_NORETRY implicitly set to avoid
> retrying memory pages compact for multiple times.
> 
> The __GFP_NORETRY is implicitly set if the size to allocate is more than
> PAGE_SZIE and when __GFP_RETRY_MAYFAIL is not explicitly set.
> 
> Cc: Aruna Ramakrishna 
> Cc: Joe Jin 
> Signed-off-by: Dongli Zhang 
> ---
> Changed since v1:
>   - To combine kzalloc() and vzalloc() as kvzalloc()
> (suggested by Jason Wang)
> 
>  drivers/vhost/scsi.c | 9 +++--
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 4ce9f00ae10e..5de21ad4bd05 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1814,12 +1814,9 @@ static int vhost_scsi_open(struct inode *inode, struct 
> file *f)
>   struct vhost_virtqueue **vqs;
>   int r = -ENOMEM, i;
>  
> - vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | 
> __GFP_RETRY_MAYFAIL);
> - if (!vs) {
> - vs = vzalloc(sizeof(*vs));
> - if (!vs)
> - goto err_vs;
> - }
> + vs = kvzalloc(sizeof(*vs), GFP_KERNEL);
> + if (!vs)
> + goto err_vs;
>  
>   vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);
>   if (!vqs)
> 
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[PATCH v2 1/1] vhost scsi: alloc vhost_scsi with kvzalloc() to avoid delay

2021-01-23 Thread Dongli Zhang 
The size of 'struct vhost_scsi' is order-10 (~2.3MB). It may take long time
delay by kzalloc() to compact memory pages by retrying multiple times when
there is a lack of high-order pages. As a result, there is latency to
create a VM (with vhost-scsi) or to hotadd vhost-scsi-based storage.

The prior commit 595cb754983d ("vhost/scsi: use vmalloc for order-10
allocation") prefers to fallback only when really needed, while this patch
allocates with kvzalloc() with __GFP_NORETRY implicitly set to avoid
retrying memory pages compact for multiple times.

The __GFP_NORETRY is implicitly set if the size to allocate is more than
PAGE_SZIE and when __GFP_RETRY_MAYFAIL is not explicitly set.

Cc: Aruna Ramakrishna 
Cc: Joe Jin 
Signed-off-by: Dongli Zhang 
---
Changed since v1:
  - To combine kzalloc() and vzalloc() as kvzalloc()
(suggested by Jason Wang)

 drivers/vhost/scsi.c | 9 +++--
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 4ce9f00ae10e..5de21ad4bd05 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1814,12 +1814,9 @@ static int vhost_scsi_open(struct inode *inode, struct 
file *f)
struct vhost_virtqueue **vqs;
int r = -ENOMEM, i;
 
-   vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | 
__GFP_RETRY_MAYFAIL);
-   if (!vs) {
-   vs = vzalloc(sizeof(*vs));
-   if (!vs)
-   goto err_vs;
-   }
+   vs = kvzalloc(sizeof(*vs), GFP_KERNEL);
+   if (!vs)
+   goto err_vs;
 
vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);
if (!vqs)
-- 
2.17.1

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