Messages in this thread | | | Subject | Re: [RFC PATCH v2 2/4] mm/__free_one_page: skip merge for order-0 page unless compaction failed | From | Daniel Jordan <> | Date | Thu, 22 Mar 2018 14:39:17 -0400 |
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On 03/22/2018 01:15 PM, Matthew Wilcox wrote: > On Tue, Mar 20, 2018 at 10:11:01PM +0800, Aaron Lu wrote: >>>> A new document file called "struct_page_filed" is added to explain >>>> the newly reused field in "struct page". >>> >>> Sounds rather ad-hoc for a single field, I'd rather document it via >>> comments. >> >> Dave would like to have a document to explain all those "struct page" >> fields that are repurposed under different scenarios and this is the >> very start of the document :-) >> >> I probably should have explained the intent of the document more. > > Dave and I are in agreement on "Shouldn't struct page be better documented". > I came up with this a few weeks ago; never quite got round to turning it > into a patch: > > +---+-----------+-----------+--------------+----------+--------+--------------+ > | B | slab | pagecache | tail 1 | anon | tail 1 | hugetlb | > +===+===========+===========+==============+==========+========+==============+ > | 0 | flags | > +---+ | > | 4 | | > +---+-----------+-----------+--------------+----------+--------+--------------+ > | 8 | s_mem | mapping | cmp_mapcount | anon_vma | defer | mapping | > +---+ | +--------------+ | list | | > |12 | | | | | | | > +---+-----------+-----------+--------------+----------+ +--------------+ > |16 | freelist | index | | index | > +---+ | | | (shifted) | > |20 | | | | | > +---+-----------+-------------------------------------+--------+--------------+ > |24 | counters | mapcount | > +---+ +-----------+--------------+----------+--------+--------------+ > |28 | | refcount | | | | refcount | > +---+-----------+-----------+--------------+----------+--------+--------------+ > |32 | next | lru | cmpd_head | | lru | > +---+ | | +-------------------+ + > |36 | | | | | | > +---+-----------+ +--------------+-------------------+ + > |40 | pages | | dtor / order | | | > +---+-----------+ +--------------+-------------------+ + > |44 | pobjects | | | | | > +---+-----------+-----------+--------------+----------------------------------+ > |48 | slb_cache | private | | | > +---+ | +--------------+----------------------------------+ > |52 | | | | | > +---+-----------+-----------+--------------+----------------------------------+
Shouldn't the anon column also contain lru?
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