Messages in this thread | | | Date | Fri, 27 Feb 2015 14:51:09 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 0/8] introduce dynamic device creation/removal |
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On Thu, 26 Feb 2015 23:10:35 +0900 Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
> Hello, > > this patchset introduces dynamic (on demand) zram device add-remove > functionality via /dev/zram-control interface. Two ioctl commands are > defined as of now (accessible in user-space via new zram.h header file): > -- ZRAM_CTL_ADD > add new device (generates device_id automatically or uses provided > device_id) > -- ZRAM_CTL_REMOVE > remove device (by device_id) > > util-linux zramctl update will be done later, after we land this patchset. > > > This also opens a possibility to drop some of sysfs device attrs and FOO_show() > code duplication in the future, and provide device stats/info via ioctl call > instead, providing something like (via zram.h): > > struct zram_info { > __u64 orig_data_size; > __u64 mem_used_total; > __u64 max_comp_streams; > > [..] > }; > > > fill it under ->init_lock in zram_fill_info() (or any other name) function and > return all device stats at once back to user-space in a single syscall. > > This is a long term plan, of course, but I'd like to see sysfs functions go away > in a year or so. What do you think?
hoo boy. Creating a /dev node and doing ioctls on it is really old school. So old school that I've forgotten why we don't do it any more.
Hopefully Alan can recall the thinking?
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