Re: [PATCH v2] Fix explanation of lower bits in the SPARSEMEM mem_map pointer

2018-01-25 Thread Michal Hocko
On Thu 25-01-18 10:05:16, Petr Tesarik wrote: > The comment is confusing. On the one hand, it refers to 32-bit > alignment (struct page alignment on 32-bit platforms), but this > would only guarantee that the 2 lowest bits must be zero. On the > other hand, it claims that at least 3 bits are availa

[PATCH v2] Fix explanation of lower bits in the SPARSEMEM mem_map pointer

2018-01-25 Thread Petr Tesarik
The comment is confusing. On the one hand, it refers to 32-bit alignment (struct page alignment on 32-bit platforms), but this would only guarantee that the 2 lowest bits must be zero. On the other hand, it claims that at least 3 bits are available, and 3 bits are actually used. This is not broken