* gnu/packages/patches/jemalloc-arm-address-bits.patch: New patch. * gnu/packages/jemalloc.scm (jemalloc)[source]: Use it. * gnu/local.mk (dist_patch_DATA): Add it.
		
			
				
	
	
		
			39 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			39 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From 8cfc9dec37b312a2686f602bbcdd102ca07cca99 Mon Sep 17 00:00:00 2001
 | 
						|
From: David Goldblatt <davidgoldblatt@fb.com>
 | 
						|
Date: Fri, 29 Sep 2017 13:54:08 -0700
 | 
						|
Subject: [PATCH] ARM: Don't extend bit LG_VADDR to compute high address bits.
 | 
						|
 | 
						|
In userspace ARM on Linux, zero-ing the high bits is the correct way to do this.
 | 
						|
This doesn't fix the fact that we currently set LG_VADDR to 48 on ARM, when in
 | 
						|
fact larger virtual address sizes are coming soon.  We'll cross that bridge when
 | 
						|
we come to it.
 | 
						|
---
 | 
						|
 include/jemalloc/internal/rtree.h | 12 ++++++++++++
 | 
						|
 1 file changed, 12 insertions(+)
 | 
						|
 | 
						|
diff --git a/include/jemalloc/internal/rtree.h b/include/jemalloc/internal/rtree.h
 | 
						|
index b5d4db39..4563db23 100644
 | 
						|
--- a/include/jemalloc/internal/rtree.h
 | 
						|
+++ b/include/jemalloc/internal/rtree.h
 | 
						|
@@ -178,9 +178,21 @@ rtree_leaf_elm_bits_read(tsdn_t *tsdn, rtree_t *rtree, rtree_leaf_elm_t *elm,
 | 
						|
 
 | 
						|
 JEMALLOC_ALWAYS_INLINE extent_t *
 | 
						|
 rtree_leaf_elm_bits_extent_get(uintptr_t bits) {
 | 
						|
+#    ifdef __aarch64__
 | 
						|
+	/*
 | 
						|
+	 * aarch64 doesn't sign extend the highest virtual address bit to set
 | 
						|
+	 * the higher ones.  Instead, the high bits gets zeroed.
 | 
						|
+	 */
 | 
						|
+	uintptr_t high_bit_mask = ((uintptr_t)1 << LG_VADDR) - 1;
 | 
						|
+	/* Mask off the slab bit. */
 | 
						|
+	uintptr_t low_bit_mask = ~(uintptr_t)1;
 | 
						|
+	uintptr_t mask = high_bit_mask & low_bit_mask;
 | 
						|
+	return (extent_t *)(bits & mask);
 | 
						|
+#    else
 | 
						|
 	/* Restore sign-extended high bits, mask slab bit. */
 | 
						|
 	return (extent_t *)((uintptr_t)((intptr_t)(bits << RTREE_NHIB) >>
 | 
						|
 	    RTREE_NHIB) & ~((uintptr_t)0x1));
 | 
						|
+#    endif
 | 
						|
 }
 | 
						|
 
 | 
						|
 JEMALLOC_ALWAYS_INLINE szind_t
 |