7069863: G1: SIGSEGV running SPECjbb2011 and -UseBiasedLocking
Align the reserved size of the heap and perm to the heap region size to get a preferred heap base that is aligned to the region size, and call the correct heap reservation constructor. Also add a check in the heap reservation code that the reserved space starts at the requested address (if any).
Reviewed-by: kvn, ysr
diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
index 63c5800..60fc14a 100644
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
@@ -1901,12 +1901,27 @@
PermanentGenerationSpec* pgs = collector_policy()->permanent_generation();
// Includes the perm-gen.
- const size_t total_reserved = max_byte_size + pgs->max_size();
+ // When compressed oops are enabled, the preferred heap base
+ // is calculated by subtracting the requested size from the
+ // 32Gb boundary and using the result as the base address for
+ // heap reservation. If the requested size is not aligned to
+ // HeapRegion::GrainBytes (i.e. the alignment that is passed
+ // into the ReservedHeapSpace constructor) then the actual
+ // base of the reserved heap may end up differing from the
+ // address that was requested (i.e. the preferred heap base).
+ // If this happens then we could end up using a non-optimal
+ // compressed oops mode.
+
+ // Since max_byte_size is aligned to the size of a heap region (checked
+ // above), we also need to align the perm gen size as it might not be.
+ const size_t total_reserved = max_byte_size +
+ align_size_up(pgs->max_size(), HeapRegion::GrainBytes);
+ Universe::check_alignment(total_reserved, HeapRegion::GrainBytes, "g1 heap and perm");
+
char* addr = Universe::preferred_heap_base(total_reserved, Universe::UnscaledNarrowOop);
- ReservedSpace heap_rs(max_byte_size + pgs->max_size(),
- HeapRegion::GrainBytes,
- UseLargePages, addr);
+ ReservedHeapSpace heap_rs(total_reserved, HeapRegion::GrainBytes,
+ UseLargePages, addr);
if (UseCompressedOops) {
if (addr != NULL && !heap_rs.is_reserved()) {
@@ -1914,14 +1929,17 @@
// region is taken already, for example, by 'java' launcher.
// Try again to reserver heap higher.
addr = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop);
- ReservedSpace heap_rs0(total_reserved, HeapRegion::GrainBytes,
- UseLargePages, addr);
+
+ ReservedHeapSpace heap_rs0(total_reserved, HeapRegion::GrainBytes,
+ UseLargePages, addr);
+
if (addr != NULL && !heap_rs0.is_reserved()) {
// Failed to reserve at specified address again - give up.
addr = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop);
assert(addr == NULL, "");
- ReservedSpace heap_rs1(total_reserved, HeapRegion::GrainBytes,
- UseLargePages, addr);
+
+ ReservedHeapSpace heap_rs1(total_reserved, HeapRegion::GrainBytes,
+ UseLargePages, addr);
heap_rs = heap_rs1;
} else {
heap_rs = heap_rs0;
diff --git a/hotspot/src/share/vm/runtime/virtualspace.cpp b/hotspot/src/share/vm/runtime/virtualspace.cpp
index 97a00ca..f290cf3 100644
--- a/hotspot/src/share/vm/runtime/virtualspace.cpp
+++ b/hotspot/src/share/vm/runtime/virtualspace.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -68,7 +68,7 @@
assert(len >= required_size, "len too small");
const size_t s = size_t(addr);
- const size_t beg_ofs = s + prefix_size & suffix_align - 1;
+ const size_t beg_ofs = (s + prefix_size) & (suffix_align - 1);
const size_t beg_delta = beg_ofs == 0 ? 0 : suffix_align - beg_ofs;
if (len < beg_delta + required_size) {
@@ -113,8 +113,8 @@
assert(res >= raw, "alignment decreased start addr");
assert(res + prefix_size + suffix_size <= raw + reserve_size,
"alignment increased end addr");
- assert((res & prefix_align - 1) == 0, "bad alignment of prefix");
- assert((res + prefix_size & suffix_align - 1) == 0,
+ assert((res & (prefix_align - 1)) == 0, "bad alignment of prefix");
+ assert(((res + prefix_size) & (suffix_align - 1)) == 0,
"bad alignment of suffix");
}
#endif
@@ -135,7 +135,7 @@
assert(UseCompressedOops, "currently requested address used only for compressed oops");
if (PrintCompressedOopsMode) {
tty->cr();
- tty->print_cr("Reserved memory at not requested address: " PTR_FORMAT " vs " PTR_FORMAT, base, requested_address);
+ tty->print_cr("Reserved memory not at requested address: " PTR_FORMAT " vs " PTR_FORMAT, base, requested_address);
}
// OS ignored requested address. Try different address.
if (special) {
@@ -162,11 +162,11 @@
assert(prefix_align != 0, "sanity");
assert(suffix_size != 0, "sanity");
assert(suffix_align != 0, "sanity");
- assert((prefix_size & prefix_align - 1) == 0,
+ assert((prefix_size & (prefix_align - 1)) == 0,
"prefix_size not divisible by prefix_align");
- assert((suffix_size & suffix_align - 1) == 0,
+ assert((suffix_size & (suffix_align - 1)) == 0,
"suffix_size not divisible by suffix_align");
- assert((suffix_align & prefix_align - 1) == 0,
+ assert((suffix_align & (prefix_align - 1)) == 0,
"suffix_align not divisible by prefix_align");
// Assert that if noaccess_prefix is used, it is the same as prefix_align.
@@ -210,8 +210,8 @@
if (addr == NULL) return;
// Check whether the result has the needed alignment (unlikely unless
- // prefix_align == suffix_align).
- const size_t ofs = size_t(addr) + adjusted_prefix_size & suffix_align - 1;
+ // prefix_align < suffix_align).
+ const size_t ofs = (size_t(addr) + adjusted_prefix_size) & (suffix_align - 1);
if (ofs != 0) {
// Wrong alignment. Release, allocate more space and do manual alignment.
//
@@ -232,6 +232,15 @@
addr = reserve_and_align(size + suffix_align, adjusted_prefix_size,
prefix_align, suffix_size, suffix_align);
}
+
+ if (requested_address != 0 &&
+ failed_to_reserve_as_requested(addr, requested_address, size, false)) {
+ // As a result of the alignment constraints, the allocated addr differs
+ // from the requested address. Return back to the caller who can
+ // take remedial action (like try again without a requested address).
+ assert(_base == NULL, "should be");
+ return;
+ }
}
_base = addr;
@@ -245,13 +254,19 @@
const size_t noaccess_prefix,
bool executable) {
const size_t granularity = os::vm_allocation_granularity();
- assert((size & granularity - 1) == 0,
+ assert((size & (granularity - 1)) == 0,
"size not aligned to os::vm_allocation_granularity()");
- assert((alignment & granularity - 1) == 0,
+ assert((alignment & (granularity - 1)) == 0,
"alignment not aligned to os::vm_allocation_granularity()");
assert(alignment == 0 || is_power_of_2((intptr_t)alignment),
"not a power of 2");
+ alignment = MAX2(alignment, (size_t)os::vm_page_size());
+
+ // Assert that if noaccess_prefix is used, it is the same as alignment.
+ assert(noaccess_prefix == 0 ||
+ noaccess_prefix == alignment, "noaccess prefix wrong");
+
_base = NULL;
_size = 0;
_special = false;
@@ -282,10 +297,8 @@
return;
}
// Check alignment constraints
- if (alignment > 0) {
- assert((uintptr_t) base % alignment == 0,
- "Large pages returned a non-aligned address");
- }
+ assert((uintptr_t) base % alignment == 0,
+ "Large pages returned a non-aligned address");
_special = true;
} else {
// failed; try to reserve regular memory below
@@ -321,7 +334,7 @@
if (base == NULL) return;
// Check alignment constraints
- if (alignment > 0 && ((size_t)base & alignment - 1) != 0) {
+ if ((((size_t)base + noaccess_prefix) & (alignment - 1)) != 0) {
// Base not aligned, retry
if (!os::release_memory(base, size)) fatal("os::release_memory failed");
// Reserve size large enough to do manual alignment and
@@ -338,12 +351,21 @@
os::release_memory(extra_base, extra_size);
base = os::reserve_memory(size, base);
} while (base == NULL);
+
+ if (requested_address != 0 &&
+ failed_to_reserve_as_requested(base, requested_address, size, false)) {
+ // As a result of the alignment constraints, the allocated base differs
+ // from the requested address. Return back to the caller who can
+ // take remedial action (like try again without a requested address).
+ assert(_base == NULL, "should be");
+ return;
+ }
}
}
// Done
_base = base;
_size = size;
- _alignment = MAX2(alignment, (size_t) os::vm_page_size());
+ _alignment = alignment;
_noaccess_prefix = noaccess_prefix;
// Assert that if noaccess_prefix is used, it is the same as alignment.
