Re: [PATCH] uio: add UIO_MEM_CUSTOM support

2017-02-15 Thread Xiubo Li
buffer(uio0 --> map0). Currently the TCMU will using the fixed small size map area as the ring buffer, but this will be the bottleneck for high iops. Without knowing how large it is enough, so the new scheme will use the fixed small ring buffer area(about 64M ~ 128M) + dynamically "growing" rin

Re: [PATCH] uio: add UIO_MEM_CUSTOM support

2017-02-15 Thread Xiubo Li
For example, the TCMU will use the map area as ISCSI commands & data ring buffer(uio0 --> map0). Currently the TCMU will using the fixed small size map area as the ring buffer, but this will be the bottleneck for high iops. Without knowing how large it is enough, so the new scheme will use the

Re: [PATCH] uio: add UIO_MEM_CUSTOM support

2017-02-15 Thread Andy Grover
On 02/15/2017 05:34 PM, Xiubo Li wrote: >>> --- a/drivers/uio/uio.c >>> +++ b/drivers/uio/uio.c >>> @@ -708,6 +708,8 @@ static int uio_mmap(struct file *filep, struct >>> vm_area_struct *vma) >>> case UIO_MEM_LOGICAL: >>> case UIO_MEM_VIRTUAL: >>> return uio_mmap_l

Re: [PATCH] uio: add UIO_MEM_CUSTOM support

2017-02-15 Thread Xiubo Li
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index fba021f..6ca0ae0 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -708,6 +708,8 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) case UIO_MEM_LOGICAL: case UIO_MEM_VIRTUAL:

Re: [PATCH] uio: add UIO_MEM_CUSTOM support

2017-02-15 Thread Greg KH
On Wed, Feb 15, 2017 at 12:43:06PM +0800, lixi...@cmss.chinamobile.com wrote: > From: Xiubo Li > > This will allow UIO based drivers, like TCMU, have opportunities to > implement their own mmap magics. > > Signed-off-by: Xiubo Li > --- > drivers/uio/uio.c | 2 ++ > include/linux/uio_d