018b162d67
This introduces a new sort of edata_t; a pageslab, and a set to manage them. This is part of a series of a commits to implement a hugepage allocator; the pageset will be per-arena, and track small page allocations requests within a larger extent allocated from a centralized hugepage allocator.
62 lines
2.1 KiB
C
62 lines
2.1 KiB
C
#ifndef JEMALLOC_INTERNAL_PSSET_H
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#define JEMALLOC_INTERNAL_PSSET_H
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/*
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* A page-slab set. What the eset is to PAC, the psset is to HPA. It maintains
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* a collection of page-slabs (the intent being that they are backed by
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* hugepages, or at least could be), and handles allocation and deallocation
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* requests.
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*
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* It has the same synchronization guarantees as the eset; stats queries don't
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* need any external synchronization, everything else does.
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*/
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/*
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* One more than the maximum pszind_t we will serve out of the HPA.
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* Practically, we expect only the first few to be actually used. This
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* corresponds to a maximum size of of 512MB on systems with 4k pages and
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* SC_NGROUP == 4, which is already an unreasonably large maximum. Morally, you
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* can think of this as being SC_NPSIZES, but there's no sense in wasting that
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* much space in the arena, making bitmaps that much larger, etc.
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*/
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#define PSSET_NPSIZES 64
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typedef struct psset_s psset_t;
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struct psset_s {
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/*
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* The pageslabs, quantized by the size class of the largest contiguous
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* free run of pages in a pageslab.
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*/
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edata_heap_t pageslabs[PSSET_NPSIZES];
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bitmap_t bitmap[BITMAP_GROUPS(PSSET_NPSIZES)];
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};
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void psset_init(psset_t *psset);
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/*
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* Tries to obtain a chunk from an existing pageslab already in the set.
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* Returns true on failure.
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*/
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bool psset_alloc_reuse(psset_t *psset, edata_t *r_edata, size_t size);
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/*
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* Given a newly created pageslab ps (not currently in the set), pass ownership
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* to the psset and allocate an extent from within it. The passed-in pageslab
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* must be at least as big as size.
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*/
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void psset_alloc_new(psset_t *psset, edata_t *ps,
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edata_t *r_edata, size_t size);
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/*
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* Given an extent that comes from a pageslab in this pageslab set, returns it
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* to its slab. Does not take ownership of the underlying edata_t.
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*
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* If some slab becomes empty as a result of the dalloc, it is retuend -- the
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* result must be checked and deallocated to the central HPA. Otherwise returns
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* NULL.
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*/
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edata_t *psset_dalloc(psset_t *psset, edata_t *edata);
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#endif /* JEMALLOC_INTERNAL_PSSET_H */
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