Allow chunks to not be naturally aligned.

Precisely size extents for huge size classes that aren't multiples of
chunksize.

4 files changed, 26 insertions, 17 deletions

diff --git a/include/jemalloc/internal/arena.h b/include/jemalloc/internal/arena.h
index fac6fd3..c298df9 100644
--- a/include/jemalloc/internal/arena.h
+++ b/include/jemalloc/internal/arena.h
@@ -486,8 +486,6 @@ void	arena_chunk_cache_maybe_remove(arena_t *arena, extent_t *extent,
 extent_t	*arena_chunk_alloc_huge(tsdn_t *tsdn, arena_t *arena,
     size_t usize, size_t alignment, bool *zero);
 void	arena_chunk_dalloc_huge(tsdn_t *tsdn, arena_t *arena, extent_t *extent);
-void	arena_chunk_ralloc_huge_similar(tsdn_t *tsdn, arena_t *arena,
-    extent_t *extent, size_t oldsize);
 void	arena_chunk_ralloc_huge_shrink(tsdn_t *tsdn, arena_t *arena,
     extent_t *extent, size_t oldsize);
 void	arena_chunk_ralloc_huge_expand(tsdn_t *tsdn, arena_t *arena,
diff --git a/include/jemalloc/internal/extent.h b/include/jemalloc/internal/extent.h
index c3bdacb..919b74f 100644
--- a/include/jemalloc/internal/extent.h
+++ b/include/jemalloc/internal/extent.h
@@ -90,6 +90,8 @@ ph_proto(, extent_heap_, extent_heap_t, extent_t)
 arena_t	*extent_arena_get(const extent_t *extent);
 void	*extent_addr_get(const extent_t *extent);
 size_t	extent_size_get(const extent_t *extent);
+void	*extent_before_get(const extent_t *extent);
+void	*extent_last_get(const extent_t *extent);
 void	*extent_past_get(const extent_t *extent);
 bool	extent_active_get(const extent_t *extent);
 bool	extent_dirty_get(const extent_t *extent);
@@ -138,6 +140,20 @@ extent_size_get(const extent_t *extent)
 }
 
 JEMALLOC_INLINE void *
+extent_before_get(const extent_t *extent)
+{
+
+	return ((void *)(uintptr_t)extent->e_addr - PAGE);
+}
+
+JEMALLOC_INLINE void *
+extent_last_get(const extent_t *extent)
+{
+
+	return ((void *)(uintptr_t)extent->e_addr + extent->e_size - PAGE);
+}
+
+JEMALLOC_INLINE void *
 extent_past_get(const extent_t *extent)
 {
 
diff --git a/include/jemalloc/internal/jemalloc_internal.h.in b/include/jemalloc/internal/jemalloc_internal.h.in
index 7afe569..ef4e052 100644
--- a/include/jemalloc/internal/jemalloc_internal.h.in
+++ b/include/jemalloc/internal/jemalloc_internal.h.in
@@ -797,14 +797,14 @@ sa2u(size_t size, size_t alignment)
 			return (usize);
 	}
 
-	/* Try for a large size class. */
-	if (likely(size <= large_maxclass) && likely(alignment < chunksize)) {
-		/*
-		 * We can't achieve subpage alignment, so round up alignment
-		 * to the minimum that can actually be supported.
-		 */
-		alignment = PAGE_CEILING(alignment);
+	/*
+	 * We can't achieve subpage alignment, so round up alignment to the
+	 * minimum that can actually be supported.
+	 */
+	alignment = PAGE_CEILING(alignment);
 
+	/* Try for a large size class. */
+	if (likely(size <= large_maxclass) && likely(alignment == PAGE)) {
 		/* Make sure result is a large size class. */
 		usize = (size <= LARGE_MINCLASS) ? LARGE_MINCLASS : s2u(size);
 
@@ -821,12 +821,6 @@ sa2u(size_t size, size_t alignment)
 	if (unlikely(alignment > HUGE_MAXCLASS))
 		return (0);
 
-	/*
-	 * We can't achieve subchunk alignment, so round up alignment to the
-	 * minimum that can actually be supported.
-	 */
-	alignment = CHUNK_CEILING(alignment);
-
 	/* Make sure result is a huge size class. */
 	if (size <= chunksize)
 		usize = chunksize;
@@ -839,7 +833,7 @@ sa2u(size_t size, size_t alignment)
 	}
 
 	/*
-	 * Calculate the multi-chunk mapping that huge_palloc() would need in
+	 * Calculate the multi-page mapping that huge_palloc() would need in
 	 * order to guarantee the alignment.
 	 */
 	if (usize + alignment < usize) {
diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt
index c446601..44a2cd3 100644
--- a/include/jemalloc/internal/private_symbols.txt
+++ b/include/jemalloc/internal/private_symbols.txt
@@ -19,7 +19,6 @@ arena_chunk_cache_maybe_remove
 arena_chunk_dalloc_huge
 arena_chunk_ralloc_huge_expand
 arena_chunk_ralloc_huge_shrink
-arena_chunk_ralloc_huge_similar
 arena_cleanup
 arena_dalloc
 arena_dalloc_bin
@@ -211,6 +210,7 @@ extent_addr_set
 extent_alloc
 extent_arena_get
 extent_arena_set
+extent_before_get
 extent_committed_get
 extent_committed_set
 extent_dalloc
@@ -219,6 +219,7 @@ extent_dirty_insert
 extent_dirty_remove
 extent_dirty_set
 extent_init
+extent_last_get
 extent_past_get
 extent_prof_tctx_get
 extent_prof_tctx_set