Re: [PATCH v3 2/4] mm/sparsemem: Defer the ms->section_mem_map clearing
From: Dave Hansen <hidden>
Date: 2018-04-09 16:02:35
Also in:
lkml
From: Dave Hansen <hidden>
Date: 2018-04-09 16:02:35
Also in:
lkml
On 04/07/2018 11:50 PM, Baoquan He wrote:
quoted
Should the " = 0" instead be clearing SECTION_MARKED_PRESENT or something? That would make it easier to match the code up with the code that it is effectively undoing.Not sure if I understand your question correctly. From memory_present(), information encoded into ms->section_mem_map including numa node, SECTION_IS_ONLINE and SECTION_MARKED_PRESENT. Not sure if it's OK to only clear SECTION_MARKED_PRESENT. People may wrongly check SECTION_IS_ONLINE and do something on this memory section?
What is mean is that, instead of: ms->section_mem_map = 0; we could literally do: ms->section_mem_map &= ~SECTION_MARKED_PRESENT; That does the same thing in practice, but makes the _intent_ much more clear.