Re: [PATCH 3/3] zram: add mem_used_max via sysfs

[David Horner]

On Thu, Aug 14, 2014 at 11:09 AM, Dan Streetman <ddstreet@xxxxxxxx> wrote:
> On Wed, Aug 13, 2014 at 9:12 PM, Minchan Kim <minchan@xxxxxxxxxx> wrote:
>> -       if (zram->limit_bytes &&
>> -               zs_get_total_size_bytes(meta->mem_pool) > zram->limit_bytes) {
>> +       total_bytes = zs_get_total_size_bytes(meta->mem_pool);
>> +       if (zram->limit_bytes && total_bytes > zram->limit_bytes) {
>
> do you need to take the init_lock to read limit_bytes here?  It could
> be getting changed between these checks...

There is no real danger in freeing with an error.
It is more timing than a race.

The max calculation is still ok because committed allocations are
added atomically.
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