Messages in this thread | | | Date | Tue, 3 May 2016 16:01:08 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 2/2] zram: user per-cpu compression streams |
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On (05/03/16 15:19), Minchan Kim wrote: > > > > cat /sys/xxx/max_comp_stream returns num_online_cpus. > > > > > > One more thing, > > > > > > User: > > > echo 4 > /sys/xxx/max_comp_stream" > > > cat /sys/xxx/max_comp_streams > > > 8 > > > > sure, it can also be > > > > cat /sys/xxx/max_comp_streams > > 5 > > cat /sys/xxx/max_comp_streams > > 6 > > cat /sys/xxx/max_comp_streams > > 7 > > cat /sys/xxx/max_comp_streams > > 3 > > > > depending on the availability of CPUs. but why would user space > > constantly check max_comp_streams? > > > > > which is rather weird? > > > > > > We should keep user's value and return it to user although it's techically > > > lying. IMO, it would be best way to prevent confusing for user until we > > > removes max_comp_streams finally. > > > > well, I preferred to show the actual state of the device. besides, > > does anyone really do > > > > write buffer to file > > if (success) > > read from file and compare with the buffer > > > > ? > > > > Okay, I want to go with your approach!
thanks. I mean that was my thinking when I decided to change the max_comp_streams output. but no pressure, it does change the numbers that user space will see. don't have any strong opinion, can keep it as zcomp cleanup only -- w/o touching the _show()/_store() parts.
> Could you update zram.txt to reflect it?
will do later today. I think I'd prefer to keep it as independent patch, since it does change the user visible behaviour after all (no idea if it's true tho; can't easily think why would anyone keep track of the values returned by cat /sys/xxx/max_comp_streams), so we can revert it w/o reverting the per-cpu streams IF anyone/anything will get upset with the change.
-ss
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