lkml.org 
[lkml]   [2017]   [Feb]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] uio: add UIO_MEM_CUSTOM support
From
Date

>> 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
>> fixed
>> small ring buffer area(about 64M ~ 128M) + dynamically "growing" ring
>> buffer
>> area(about 1.5G).
> The following code is in uio_mmap() in uio.c:
>
> if (idev->info->mmap) {
> ret = idev->info->mmap(idev->info, vma);
> return ret;

Yes, just missed this return.
> }
>
> switch (idev->info->mem[mi].memtype) {
> case UIO_MEM_PHYS:
> return uio_mmap_physical(vma);
> case UIO_MEM_LOGICAL:
> case UIO_MEM_VIRTUAL:
> return uio_mmap_logical(vma);
> default:
> return -EINVAL;
> }
>
> We already have the equivalent of a CUSTOM memtype because TCMU sets the
> info->mmap fn, overriding uio's default handling choices in favor of its
> own.
>
> HTH -- Regards -- Andy
>



\
 
 \ /
  Last update: 2017-02-16 06:34    [W:0.058 / U:0.676 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site