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authorKent Overstreet <kent.overstreet@linux.dev>2024-01-16 17:00:02 -0500
committerKent Overstreet <kent.overstreet@linux.dev>2024-01-16 17:17:23 -0500
commitb5fd066153c40a70a29caa1ea7987723ab687763 (patch)
tree6d43a8b0a90d549a54c65565ac96c92b3e84b594 /c_src/raid/memory.h
parent06ff8b55b70fda44d91b31b5511fafd1680a8934 (diff)
Move c_src dirs back to toplevel
We just wanted c sourcefiles out of the top level, not c source directories. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'c_src/raid/memory.h')
-rw-r--r--c_src/raid/memory.h96
1 files changed, 0 insertions, 96 deletions
diff --git a/c_src/raid/memory.h b/c_src/raid/memory.h
deleted file mode 100644
index de00614f..00000000
--- a/c_src/raid/memory.h
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright (C) 2013 Andrea Mazzoleni
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#ifndef __RAID_MEMORY_H
-#define __RAID_MEMORY_H
-
-/**
- * Memory alignment provided by raid_malloc().
- *
- * It should guarantee good cache performance everywhere.
- */
-#define RAID_MALLOC_ALIGN 256
-
-/**
- * Memory displacement to avoid cache address sharing on contiguous blocks,
- * used by raid_malloc_vector().
- *
- * When allocating a sequence of blocks with a size of power of 2,
- * there is the risk that the addresses of each block are mapped into the
- * same cache line and prefetching predictor, resulting in a lot of cache
- * sharing if you access all the blocks in parallel, from the start to the
- * end.
- *
- * To avoid this effect, it's better if all the blocks are allocated
- * with a fixed displacement trying to reduce the cache addresses sharing.
- *
- * The selected displacement was chosen empirically with some speed tests
- * with 8/12/16/20/24 data buffers of 256 KB.
- *
- * These are the results in MB/s with no displacement:
- *
- * sse2
- * gen1 15368 [MB/s]
- * gen2 6814 [MB/s]
- * genz 3033 [MB/s]
- *
- * These are the results with displacement resulting in improvments
- * in the order of 20% or more:
- *
- * sse2
- * gen1 21936 [MB/s]
- * gen2 11902 [MB/s]
- * genz 5838 [MB/s]
- *
- */
-#define RAID_MALLOC_DISPLACEMENT (7*256)
-
-/**
- * Aligned malloc.
- * Use an alignment suitable for the raid functions.
- */
-void *raid_malloc(size_t size, void **freeptr);
-
-/**
- * Arbitrary aligned malloc.
- */
-void *raid_malloc_align(size_t size, size_t align_size, void **freeptr);
-
-/**
- * Aligned vector allocation.
- * Use an alignment suitable for the raid functions.
- * Returns a vector of @n pointers, each one pointing to a block of
- * the specified @size.
- * The first @nd elements are reversed in order.
- */
-void **raid_malloc_vector(int nd, int n, size_t size, void **freeptr);
-
-/**
- * Arbitrary aligned vector allocation.
- */
-void **raid_malloc_vector_align(int nd, int n, size_t size, size_t align_size, size_t displacement_size, void **freeptr);
-
-/**
- * Fills the memory vector with pseudo-random data based on the specified seed.
- */
-void raid_mrand_vector(unsigned seed, int n, size_t size, void **vv);
-
-/**
- * Tests the memory vector for RAM problems.
- * If a problem is found, it crashes.
- */
-int raid_mtest_vector(int n, size_t size, void **vv);
-
-#endif
-