| // Copyright 2019 The Go Authors. All rights reserved. | 
 | // Use of this source code is governed by a BSD-style | 
 | // license that can be found in the LICENSE file. | 
 |  | 
 | package runtime_test | 
 |  | 
 | import ( | 
 | 	"fmt" | 
 | 	. "runtime" | 
 | 	"testing" | 
 | ) | 
 |  | 
 | func checkPageAlloc(t *testing.T, want, got *PageAlloc) { | 
 | 	// Ensure start and end are correct. | 
 | 	wantStart, wantEnd := want.Bounds() | 
 | 	gotStart, gotEnd := got.Bounds() | 
 | 	if gotStart != wantStart { | 
 | 		t.Fatalf("start values not equal: got %d, want %d", gotStart, wantStart) | 
 | 	} | 
 | 	if gotEnd != wantEnd { | 
 | 		t.Fatalf("end values not equal: got %d, want %d", gotEnd, wantEnd) | 
 | 	} | 
 |  | 
 | 	for i := gotStart; i < gotEnd; i++ { | 
 | 		// Check the bitmaps. Note that we may have nil data. | 
 | 		gb, wb := got.PallocData(i), want.PallocData(i) | 
 | 		if gb == nil && wb == nil { | 
 | 			continue | 
 | 		} | 
 | 		if (gb == nil && wb != nil) || (gb != nil && wb == nil) { | 
 | 			t.Errorf("chunk %d nilness mismatch", i) | 
 | 		} | 
 | 		if !checkPallocBits(t, gb.PallocBits(), wb.PallocBits()) { | 
 | 			t.Logf("in chunk %d (mallocBits)", i) | 
 | 		} | 
 | 		if !checkPallocBits(t, gb.Scavenged(), wb.Scavenged()) { | 
 | 			t.Logf("in chunk %d (scavenged)", i) | 
 | 		} | 
 | 	} | 
 | 	// TODO(mknyszek): Verify summaries too? | 
 | } | 
 |  | 
 | func TestPageAllocGrow(t *testing.T) { | 
 | 	if GOOS == "openbsd" && testing.Short() { | 
 | 		t.Skip("skipping because virtual memory is limited; see #36210") | 
 | 	} | 
 | 	type test struct { | 
 | 		chunks []ChunkIdx | 
 | 		inUse  []AddrRange | 
 | 	} | 
 | 	tests := map[string]test{ | 
 | 		"One": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+1, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"Contiguous2": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 1, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+2, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"Contiguous5": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 1, | 
 | 				BaseChunkIdx + 2, | 
 | 				BaseChunkIdx + 3, | 
 | 				BaseChunkIdx + 4, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+5, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"Discontiguous": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 2, | 
 | 				BaseChunkIdx + 4, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+1, 0)}, | 
 | 				{PageBase(BaseChunkIdx+2, 0), PageBase(BaseChunkIdx+3, 0)}, | 
 | 				{PageBase(BaseChunkIdx+4, 0), PageBase(BaseChunkIdx+5, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"Mixed": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 1, | 
 | 				BaseChunkIdx + 2, | 
 | 				BaseChunkIdx + 4, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+3, 0)}, | 
 | 				{PageBase(BaseChunkIdx+4, 0), PageBase(BaseChunkIdx+5, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"WildlyDiscontiguous": { | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 1, | 
 | 				BaseChunkIdx + 0x10, | 
 | 				BaseChunkIdx + 0x21, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+2, 0)}, | 
 | 				{PageBase(BaseChunkIdx+0x10, 0), PageBase(BaseChunkIdx+0x11, 0)}, | 
 | 				{PageBase(BaseChunkIdx+0x21, 0), PageBase(BaseChunkIdx+0x22, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 		"ManyDiscontiguous": { | 
 | 			// The initial cap is 16. Test 33 ranges, to exercise the growth path (twice). | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, BaseChunkIdx + 2, BaseChunkIdx + 4, BaseChunkIdx + 6, | 
 | 				BaseChunkIdx + 8, BaseChunkIdx + 10, BaseChunkIdx + 12, BaseChunkIdx + 14, | 
 | 				BaseChunkIdx + 16, BaseChunkIdx + 18, BaseChunkIdx + 20, BaseChunkIdx + 22, | 
 | 				BaseChunkIdx + 24, BaseChunkIdx + 26, BaseChunkIdx + 28, BaseChunkIdx + 30, | 
 | 				BaseChunkIdx + 32, BaseChunkIdx + 34, BaseChunkIdx + 36, BaseChunkIdx + 38, | 
 | 				BaseChunkIdx + 40, BaseChunkIdx + 42, BaseChunkIdx + 44, BaseChunkIdx + 46, | 
 | 				BaseChunkIdx + 48, BaseChunkIdx + 50, BaseChunkIdx + 52, BaseChunkIdx + 54, | 
 | 				BaseChunkIdx + 56, BaseChunkIdx + 58, BaseChunkIdx + 60, BaseChunkIdx + 62, | 
 | 				BaseChunkIdx + 64, | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+1, 0)}, | 
 | 				{PageBase(BaseChunkIdx+2, 0), PageBase(BaseChunkIdx+3, 0)}, | 
 | 				{PageBase(BaseChunkIdx+4, 0), PageBase(BaseChunkIdx+5, 0)}, | 
 | 				{PageBase(BaseChunkIdx+6, 0), PageBase(BaseChunkIdx+7, 0)}, | 
 | 				{PageBase(BaseChunkIdx+8, 0), PageBase(BaseChunkIdx+9, 0)}, | 
 | 				{PageBase(BaseChunkIdx+10, 0), PageBase(BaseChunkIdx+11, 0)}, | 
 | 				{PageBase(BaseChunkIdx+12, 0), PageBase(BaseChunkIdx+13, 0)}, | 
 | 				{PageBase(BaseChunkIdx+14, 0), PageBase(BaseChunkIdx+15, 0)}, | 
 | 				{PageBase(BaseChunkIdx+16, 0), PageBase(BaseChunkIdx+17, 0)}, | 
 | 				{PageBase(BaseChunkIdx+18, 0), PageBase(BaseChunkIdx+19, 0)}, | 
 | 				{PageBase(BaseChunkIdx+20, 0), PageBase(BaseChunkIdx+21, 0)}, | 
 | 				{PageBase(BaseChunkIdx+22, 0), PageBase(BaseChunkIdx+23, 0)}, | 
 | 				{PageBase(BaseChunkIdx+24, 0), PageBase(BaseChunkIdx+25, 0)}, | 
 | 				{PageBase(BaseChunkIdx+26, 0), PageBase(BaseChunkIdx+27, 0)}, | 
 | 				{PageBase(BaseChunkIdx+28, 0), PageBase(BaseChunkIdx+29, 0)}, | 
 | 				{PageBase(BaseChunkIdx+30, 0), PageBase(BaseChunkIdx+31, 0)}, | 
 | 				{PageBase(BaseChunkIdx+32, 0), PageBase(BaseChunkIdx+33, 0)}, | 
 | 				{PageBase(BaseChunkIdx+34, 0), PageBase(BaseChunkIdx+35, 0)}, | 
 | 				{PageBase(BaseChunkIdx+36, 0), PageBase(BaseChunkIdx+37, 0)}, | 
 | 				{PageBase(BaseChunkIdx+38, 0), PageBase(BaseChunkIdx+39, 0)}, | 
 | 				{PageBase(BaseChunkIdx+40, 0), PageBase(BaseChunkIdx+41, 0)}, | 
 | 				{PageBase(BaseChunkIdx+42, 0), PageBase(BaseChunkIdx+43, 0)}, | 
 | 				{PageBase(BaseChunkIdx+44, 0), PageBase(BaseChunkIdx+45, 0)}, | 
 | 				{PageBase(BaseChunkIdx+46, 0), PageBase(BaseChunkIdx+47, 0)}, | 
 | 				{PageBase(BaseChunkIdx+48, 0), PageBase(BaseChunkIdx+49, 0)}, | 
 | 				{PageBase(BaseChunkIdx+50, 0), PageBase(BaseChunkIdx+51, 0)}, | 
 | 				{PageBase(BaseChunkIdx+52, 0), PageBase(BaseChunkIdx+53, 0)}, | 
 | 				{PageBase(BaseChunkIdx+54, 0), PageBase(BaseChunkIdx+55, 0)}, | 
 | 				{PageBase(BaseChunkIdx+56, 0), PageBase(BaseChunkIdx+57, 0)}, | 
 | 				{PageBase(BaseChunkIdx+58, 0), PageBase(BaseChunkIdx+59, 0)}, | 
 | 				{PageBase(BaseChunkIdx+60, 0), PageBase(BaseChunkIdx+61, 0)}, | 
 | 				{PageBase(BaseChunkIdx+62, 0), PageBase(BaseChunkIdx+63, 0)}, | 
 | 				{PageBase(BaseChunkIdx+64, 0), PageBase(BaseChunkIdx+65, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 	} | 
 | 	if PageAlloc64Bit != 0 { | 
 | 		tests["ExtremelyDiscontiguous"] = test{ | 
 | 			chunks: []ChunkIdx{ | 
 | 				BaseChunkIdx, | 
 | 				BaseChunkIdx + 0x100000, // constant translates to O(TiB) | 
 | 			}, | 
 | 			inUse: []AddrRange{ | 
 | 				{PageBase(BaseChunkIdx, 0), PageBase(BaseChunkIdx+1, 0)}, | 
 | 				{PageBase(BaseChunkIdx+0x100000, 0), PageBase(BaseChunkIdx+0x100001, 0)}, | 
 | 			}, | 
 | 		} | 
 | 	} | 
 | 	for name, v := range tests { | 
 | 		v := v | 
 | 		t.Run(name, func(t *testing.T) { | 
 | 			// By creating a new pageAlloc, we will | 
 | 			// grow it for each chunk defined in x. | 
 | 			x := make(map[ChunkIdx][]BitRange) | 
 | 			for _, c := range v.chunks { | 
 | 				x[c] = []BitRange{} | 
 | 			} | 
 | 			b := NewPageAlloc(x, nil) | 
 | 			defer FreePageAlloc(b) | 
 |  | 
 | 			got := b.InUse() | 
 | 			want := v.inUse | 
 |  | 
 | 			// Check for mismatches. | 
 | 			if len(got) != len(want) { | 
 | 				t.Fail() | 
 | 			} else { | 
 | 				for i := range want { | 
 | 					if want[i] != got[i] { | 
 | 						t.Fail() | 
 | 						break | 
 | 					} | 
 | 				} | 
 | 			} | 
 | 			if t.Failed() { | 
 | 				t.Logf("found inUse mismatch") | 
 | 				t.Logf("got:") | 
 | 				for i, r := range got { | 
 | 					t.Logf("\t#%d [0x%x, 0x%x)", i, r.Base, r.Limit) | 
 | 				} | 
 | 				t.Logf("want:") | 
 | 				for i, r := range want { | 
 | 					t.Logf("\t#%d [0x%x, 0x%x)", i, r.Base, r.Limit) | 
 | 				} | 
 | 			} | 
 | 		}) | 
 | 	} | 
 | } | 
 |  | 
 | func TestPageAllocAlloc(t *testing.T) { | 
 | 	if GOOS == "openbsd" && testing.Short() { | 
 | 		t.Skip("skipping because virtual memory is limited; see #36210") | 
 | 	} | 
 | 	type hit struct { | 
 | 		npages, base, scav uintptr | 
 | 	} | 
 | 	type test struct { | 
 | 		scav   map[ChunkIdx][]BitRange | 
 | 		before map[ChunkIdx][]BitRange | 
 | 		after  map[ChunkIdx][]BitRange | 
 | 		hits   []hit | 
 | 	} | 
 | 	tests := map[string]test{ | 
 | 		"AllFree1": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 1}, {2, 2}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{1, PageBase(BaseChunkIdx, 0), PageSize}, | 
 | 				{1, PageBase(BaseChunkIdx, 1), 0}, | 
 | 				{1, PageBase(BaseChunkIdx, 2), PageSize}, | 
 | 				{1, PageBase(BaseChunkIdx, 3), PageSize}, | 
 | 				{1, PageBase(BaseChunkIdx, 4), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 5}}, | 
 | 			}, | 
 | 		}, | 
 | 		"ManyArena1": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages - 1}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{1, PageBase(BaseChunkIdx+2, PallocChunkPages-1), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"NotContiguous1": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 0xff: {{0, 0}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 0xff: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{1, PageBase(BaseChunkIdx+0xff, 0), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 0xff: {{0, 1}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFree2": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 3}, {7, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{2, PageBase(BaseChunkIdx, 0), 2 * PageSize}, | 
 | 				{2, PageBase(BaseChunkIdx, 2), PageSize}, | 
 | 				{2, PageBase(BaseChunkIdx, 4), 0}, | 
 | 				{2, PageBase(BaseChunkIdx, 6), PageSize}, | 
 | 				{2, PageBase(BaseChunkIdx, 8), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 10}}, | 
 | 			}, | 
 | 		}, | 
 | 		"Straddle2": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages - 1}}, | 
 | 				BaseChunkIdx + 1: {{1, PallocChunkPages - 1}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{PallocChunkPages - 1, 1}}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{2, PageBase(BaseChunkIdx, PallocChunkPages-1), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFree5": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 8}, {9, 1}, {17, 5}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{5, PageBase(BaseChunkIdx, 0), 5 * PageSize}, | 
 | 				{5, PageBase(BaseChunkIdx, 5), 4 * PageSize}, | 
 | 				{5, PageBase(BaseChunkIdx, 10), 0}, | 
 | 				{5, PageBase(BaseChunkIdx, 15), 3 * PageSize}, | 
 | 				{5, PageBase(BaseChunkIdx, 20), 2 * PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 25}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFree64": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{21, 1}, {63, 65}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{64, PageBase(BaseChunkIdx, 0), 2 * PageSize}, | 
 | 				{64, PageBase(BaseChunkIdx, 64), 64 * PageSize}, | 
 | 				{64, PageBase(BaseChunkIdx, 128), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 192}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFree65": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{129, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{65, PageBase(BaseChunkIdx, 0), 0}, | 
 | 				{65, PageBase(BaseChunkIdx, 65), PageSize}, | 
 | 				{65, PageBase(BaseChunkIdx, 130), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 195}}, | 
 | 			}, | 
 | 		}, | 
 | 		"ExhaustPallocChunkPages-3": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{10, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages - 3, PageBase(BaseChunkIdx, 0), PageSize}, | 
 | 				{PallocChunkPages - 3, 0, 0}, | 
 | 				{1, PageBase(BaseChunkIdx, PallocChunkPages-3), 0}, | 
 | 				{2, PageBase(BaseChunkIdx, PallocChunkPages-2), 0}, | 
 | 				{1, 0, 0}, | 
 | 				{PallocChunkPages - 3, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFreePallocChunkPages": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, 1}, {PallocChunkPages - 1, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages, PageBase(BaseChunkIdx, 0), 2 * PageSize}, | 
 | 				{PallocChunkPages, 0, 0}, | 
 | 				{1, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {{PallocChunkPages / 2, PallocChunkPages / 2}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {{3, 100}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages, PageBase(BaseChunkIdx, PallocChunkPages/2), 100 * PageSize}, | 
 | 				{PallocChunkPages, 0, 0}, | 
 | 				{1, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages+1": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages + 1, PageBase(BaseChunkIdx, PallocChunkPages/2), (PallocChunkPages + 1) * PageSize}, | 
 | 				{PallocChunkPages, 0, 0}, | 
 | 				{1, PageBase(BaseChunkIdx+1, PallocChunkPages/2+1), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages/2 + 2}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFreePallocChunkPages*2": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages * 2, PageBase(BaseChunkIdx, 0), 0}, | 
 | 				{PallocChunkPages * 2, 0, 0}, | 
 | 				{1, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"NotContiguousPallocChunkPages*2": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {}, | 
 | 				BaseChunkIdx + 0x40: {}, | 
 | 				BaseChunkIdx + 0x41: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 0x40: {}, | 
 | 				BaseChunkIdx + 0x41: {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages * 2, PageBase(BaseChunkIdx+0x40, 0), 0}, | 
 | 				{21, PageBase(BaseChunkIdx, 0), 21 * PageSize}, | 
 | 				{1, PageBase(BaseChunkIdx, 21), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:        {{0, 22}}, | 
 | 				BaseChunkIdx + 0x40: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 0x41: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages*2": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 				BaseChunkIdx + 2: {{PallocChunkPages / 2, PallocChunkPages / 2}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, 7}}, | 
 | 				BaseChunkIdx + 1: {{3, 5}, {121, 10}}, | 
 | 				BaseChunkIdx + 2: {{PallocChunkPages/2 + 12, 2}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages * 2, PageBase(BaseChunkIdx, PallocChunkPages/2), 15 * PageSize}, | 
 | 				{PallocChunkPages * 2, 0, 0}, | 
 | 				{1, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages*5/4": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages * 3 / 4}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages * 3 / 4}}, | 
 | 				BaseChunkIdx + 3: {{0, 0}}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{PallocChunkPages / 2, PallocChunkPages/4 + 1}}, | 
 | 				BaseChunkIdx + 2: {{PallocChunkPages / 3, 1}}, | 
 | 				BaseChunkIdx + 3: {{PallocChunkPages * 2 / 3, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages * 5 / 4, PageBase(BaseChunkIdx+2, PallocChunkPages*3/4), PageSize}, | 
 | 				{PallocChunkPages * 5 / 4, 0, 0}, | 
 | 				{1, PageBase(BaseChunkIdx+1, PallocChunkPages*3/4), PageSize}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages*3/4 + 1}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 3: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFreePallocChunkPages*7+5": { | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 				BaseChunkIdx + 2: {}, | 
 | 				BaseChunkIdx + 3: {}, | 
 | 				BaseChunkIdx + 4: {}, | 
 | 				BaseChunkIdx + 5: {}, | 
 | 				BaseChunkIdx + 6: {}, | 
 | 				BaseChunkIdx + 7: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{50, 1}}, | 
 | 				BaseChunkIdx + 1: {{31, 1}}, | 
 | 				BaseChunkIdx + 2: {{7, 1}}, | 
 | 				BaseChunkIdx + 3: {{200, 1}}, | 
 | 				BaseChunkIdx + 4: {{3, 1}}, | 
 | 				BaseChunkIdx + 5: {{51, 1}}, | 
 | 				BaseChunkIdx + 6: {{20, 1}}, | 
 | 				BaseChunkIdx + 7: {{1, 1}}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages*7 + 5, PageBase(BaseChunkIdx, 0), 8 * PageSize}, | 
 | 				{PallocChunkPages*7 + 5, 0, 0}, | 
 | 				{1, PageBase(BaseChunkIdx+7, 5), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 3: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 4: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 5: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 6: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 7: {{0, 6}}, | 
 | 			}, | 
 | 		}, | 
 | 	} | 
 | 	if PageAlloc64Bit != 0 { | 
 | 		const chunkIdxBigJump = 0x100000 // chunk index offset which translates to O(TiB) | 
 |  | 
 | 		// This test attempts to trigger a bug wherein we look at unmapped summary | 
 | 		// memory that isn't just in the case where we exhaust the heap. | 
 | 		// | 
 | 		// It achieves this by placing a chunk such that its summary will be | 
 | 		// at the very end of a physical page. It then also places another chunk | 
 | 		// much further up in the address space, such that any allocations into the | 
 | 		// first chunk do not exhaust the heap and the second chunk's summary is not in the | 
 | 		// page immediately adjacent to the first chunk's summary's page. | 
 | 		// Allocating into this first chunk to exhaustion and then into the second | 
 | 		// chunk may then trigger a check in the allocator which erroneously looks at | 
 | 		// unmapped summary memory and crashes. | 
 |  | 
 | 		// Figure out how many chunks are in a physical page, then align BaseChunkIdx | 
 | 		// to a physical page in the chunk summary array. Here we only assume that | 
 | 		// each summary array is aligned to some physical page. | 
 | 		sumsPerPhysPage := ChunkIdx(PhysPageSize / PallocSumBytes) | 
 | 		baseChunkIdx := BaseChunkIdx &^ (sumsPerPhysPage - 1) | 
 | 		tests["DiscontiguousMappedSumBoundary"] = test{ | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				baseChunkIdx + sumsPerPhysPage - 1: {}, | 
 | 				baseChunkIdx + chunkIdxBigJump:     {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				baseChunkIdx + sumsPerPhysPage - 1: {}, | 
 | 				baseChunkIdx + chunkIdxBigJump:     {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{PallocChunkPages - 1, PageBase(baseChunkIdx+sumsPerPhysPage-1, 0), 0}, | 
 | 				{1, PageBase(baseChunkIdx+sumsPerPhysPage-1, PallocChunkPages-1), 0}, | 
 | 				{1, PageBase(baseChunkIdx+chunkIdxBigJump, 0), 0}, | 
 | 				{PallocChunkPages - 1, PageBase(baseChunkIdx+chunkIdxBigJump, 1), 0}, | 
 | 				{1, 0, 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				baseChunkIdx + sumsPerPhysPage - 1: {{0, PallocChunkPages}}, | 
 | 				baseChunkIdx + chunkIdxBigJump:     {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 		} | 
 |  | 
 | 		// Test to check for issue #40191. Essentially, the candidate searchAddr | 
 | 		// discovered by find may not point to mapped memory, so we need to handle | 
 | 		// that explicitly. | 
 | 		// | 
 | 		// chunkIdxSmallOffset is an offset intended to be used within chunkIdxBigJump. | 
 | 		// It is far enough within chunkIdxBigJump that the summaries at the beginning | 
 | 		// of an address range the size of chunkIdxBigJump will not be mapped in. | 
 | 		const chunkIdxSmallOffset = 0x503 | 
 | 		tests["DiscontiguousBadSearchAddr"] = test{ | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				// The mechanism for the bug involves three chunks, A, B, and C, which are | 
 | 				// far apart in the address space. In particular, B is chunkIdxBigJump + | 
 | 				// chunkIdxSmalloffset chunks away from B, and C is 2*chunkIdxBigJump chunks | 
 | 				// away from A. A has 1 page free, B has several (NOT at the end of B), and | 
 | 				// C is totally free. | 
 | 				// Note that B's free memory must not be at the end of B because the fast | 
 | 				// path in the page allocator will check if the searchAddr even gives us | 
 | 				// enough space to place the allocation in a chunk before accessing the | 
 | 				// summary. | 
 | 				BaseChunkIdx + chunkIdxBigJump*0: {{0, PallocChunkPages - 1}}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*1 + chunkIdxSmallOffset: { | 
 | 					{0, PallocChunkPages - 10}, | 
 | 					{PallocChunkPages - 1, 1}, | 
 | 				}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*2: {}, | 
 | 			}, | 
 | 			scav: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx + chunkIdxBigJump*0:                       {}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*1 + chunkIdxSmallOffset: {}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*2:                       {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				// We first allocate into A to set the page allocator's searchAddr to the | 
 | 				// end of that chunk. That is the only purpose A serves. | 
 | 				{1, PageBase(BaseChunkIdx, PallocChunkPages-1), 0}, | 
 | 				// Then, we make a big allocation that doesn't fit into B, and so must be | 
 | 				// fulfilled by C. | 
 | 				// | 
 | 				// On the way to fulfilling the allocation into C, we estimate searchAddr | 
 | 				// using the summary structure, but that will give us a searchAddr of | 
 | 				// B's base address minus chunkIdxSmallOffset chunks. These chunks will | 
 | 				// not be mapped. | 
 | 				{100, PageBase(baseChunkIdx+chunkIdxBigJump*2, 0), 0}, | 
 | 				// Now we try to make a smaller allocation that can be fulfilled by B. | 
 | 				// In an older implementation of the page allocator, this will segfault, | 
 | 				// because this last allocation will first try to access the summary | 
 | 				// for B's base address minus chunkIdxSmallOffset chunks in the fast path, | 
 | 				// and this will not be mapped. | 
 | 				{9, PageBase(baseChunkIdx+chunkIdxBigJump*1+chunkIdxSmallOffset, PallocChunkPages-10), 0}, | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx + chunkIdxBigJump*0:                       {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*1 + chunkIdxSmallOffset: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + chunkIdxBigJump*2:                       {{0, 100}}, | 
 | 			}, | 
 | 		} | 
 | 	} | 
 | 	for name, v := range tests { | 
 | 		v := v | 
 | 		t.Run(name, func(t *testing.T) { | 
 | 			b := NewPageAlloc(v.before, v.scav) | 
 | 			defer FreePageAlloc(b) | 
 |  | 
 | 			for iter, i := range v.hits { | 
 | 				a, s := b.Alloc(i.npages) | 
 | 				if a != i.base { | 
 | 					t.Fatalf("bad alloc #%d: want base 0x%x, got 0x%x", iter+1, i.base, a) | 
 | 				} | 
 | 				if s != i.scav { | 
 | 					t.Fatalf("bad alloc #%d: want scav %d, got %d", iter+1, i.scav, s) | 
 | 				} | 
 | 			} | 
 | 			want := NewPageAlloc(v.after, v.scav) | 
 | 			defer FreePageAlloc(want) | 
 |  | 
 | 			checkPageAlloc(t, want, b) | 
 | 		}) | 
 | 	} | 
 | } | 
 |  | 
 | func TestPageAllocExhaust(t *testing.T) { | 
 | 	if GOOS == "openbsd" && testing.Short() { | 
 | 		t.Skip("skipping because virtual memory is limited; see #36210") | 
 | 	} | 
 | 	for _, npages := range []uintptr{1, 2, 3, 4, 5, 8, 16, 64, 1024, 1025, 2048, 2049} { | 
 | 		npages := npages | 
 | 		t.Run(fmt.Sprintf("%d", npages), func(t *testing.T) { | 
 | 			// Construct b. | 
 | 			bDesc := make(map[ChunkIdx][]BitRange) | 
 | 			for i := ChunkIdx(0); i < 4; i++ { | 
 | 				bDesc[BaseChunkIdx+i] = []BitRange{} | 
 | 			} | 
 | 			b := NewPageAlloc(bDesc, nil) | 
 | 			defer FreePageAlloc(b) | 
 |  | 
 | 			// Allocate into b with npages until we've exhausted the heap. | 
 | 			nAlloc := (PallocChunkPages * 4) / int(npages) | 
 | 			for i := 0; i < nAlloc; i++ { | 
 | 				addr := PageBase(BaseChunkIdx, uint(i)*uint(npages)) | 
 | 				if a, _ := b.Alloc(npages); a != addr { | 
 | 					t.Fatalf("bad alloc #%d: want 0x%x, got 0x%x", i+1, addr, a) | 
 | 				} | 
 | 			} | 
 |  | 
 | 			// Check to make sure the next allocation fails. | 
 | 			if a, _ := b.Alloc(npages); a != 0 { | 
 | 				t.Fatalf("bad alloc #%d: want 0, got 0x%x", nAlloc, a) | 
 | 			} | 
 |  | 
 | 			// Construct what we want the heap to look like now. | 
 | 			allocPages := nAlloc * int(npages) | 
 | 			wantDesc := make(map[ChunkIdx][]BitRange) | 
 | 			for i := ChunkIdx(0); i < 4; i++ { | 
 | 				if allocPages >= PallocChunkPages { | 
 | 					wantDesc[BaseChunkIdx+i] = []BitRange{{0, PallocChunkPages}} | 
 | 					allocPages -= PallocChunkPages | 
 | 				} else if allocPages > 0 { | 
 | 					wantDesc[BaseChunkIdx+i] = []BitRange{{0, uint(allocPages)}} | 
 | 					allocPages = 0 | 
 | 				} else { | 
 | 					wantDesc[BaseChunkIdx+i] = []BitRange{} | 
 | 				} | 
 | 			} | 
 | 			want := NewPageAlloc(wantDesc, nil) | 
 | 			defer FreePageAlloc(want) | 
 |  | 
 | 			// Check to make sure the heap b matches what we want. | 
 | 			checkPageAlloc(t, want, b) | 
 | 		}) | 
 | 	} | 
 | } | 
 |  | 
 | func TestPageAllocFree(t *testing.T) { | 
 | 	if GOOS == "openbsd" && testing.Short() { | 
 | 		t.Skip("skipping because virtual memory is limited; see #36210") | 
 | 	} | 
 | 	tests := map[string]struct { | 
 | 		before map[ChunkIdx][]BitRange | 
 | 		after  map[ChunkIdx][]BitRange | 
 | 		npages uintptr | 
 | 		frees  []uintptr | 
 | 	}{ | 
 | 		"Free1": { | 
 | 			npages: 1, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 				PageBase(BaseChunkIdx, 1), | 
 | 				PageBase(BaseChunkIdx, 2), | 
 | 				PageBase(BaseChunkIdx, 3), | 
 | 				PageBase(BaseChunkIdx, 4), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{5, PallocChunkPages - 5}}, | 
 | 			}, | 
 | 		}, | 
 | 		"ManyArena1": { | 
 | 			npages: 1, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, PallocChunkPages/2), | 
 | 				PageBase(BaseChunkIdx+1, 0), | 
 | 				PageBase(BaseChunkIdx+2, PallocChunkPages-1), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}, {PallocChunkPages/2 + 1, PallocChunkPages/2 - 1}}, | 
 | 				BaseChunkIdx + 1: {{1, PallocChunkPages - 1}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages - 1}}, | 
 | 			}, | 
 | 		}, | 
 | 		"Free2": { | 
 | 			npages: 2, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 				PageBase(BaseChunkIdx, 2), | 
 | 				PageBase(BaseChunkIdx, 4), | 
 | 				PageBase(BaseChunkIdx, 6), | 
 | 				PageBase(BaseChunkIdx, 8), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{10, PallocChunkPages - 10}}, | 
 | 			}, | 
 | 		}, | 
 | 		"Straddle2": { | 
 | 			npages: 2, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{PallocChunkPages - 1, 1}}, | 
 | 				BaseChunkIdx + 1: {{0, 1}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, PallocChunkPages-1), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 		}, | 
 | 		"Free5": { | 
 | 			npages: 5, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 				PageBase(BaseChunkIdx, 5), | 
 | 				PageBase(BaseChunkIdx, 10), | 
 | 				PageBase(BaseChunkIdx, 15), | 
 | 				PageBase(BaseChunkIdx, 20), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{25, PallocChunkPages - 25}}, | 
 | 			}, | 
 | 		}, | 
 | 		"Free64": { | 
 | 			npages: 64, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 				PageBase(BaseChunkIdx, 64), | 
 | 				PageBase(BaseChunkIdx, 128), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{192, PallocChunkPages - 192}}, | 
 | 			}, | 
 | 		}, | 
 | 		"Free65": { | 
 | 			npages: 65, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 				PageBase(BaseChunkIdx, 65), | 
 | 				PageBase(BaseChunkIdx, 130), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{195, PallocChunkPages - 195}}, | 
 | 			}, | 
 | 		}, | 
 | 		"FreePallocChunkPages": { | 
 | 			npages: PallocChunkPages, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx: {}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages": { | 
 | 			npages: PallocChunkPages, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{PallocChunkPages / 2, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages / 2}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, PallocChunkPages/2), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages+1": { | 
 | 			npages: PallocChunkPages + 1, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, PallocChunkPages/2), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {{PallocChunkPages/2 + 1, PallocChunkPages/2 - 1}}, | 
 | 			}, | 
 | 		}, | 
 | 		"FreePallocChunkPages*2": { | 
 | 			npages: PallocChunkPages * 2, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 			}, | 
 | 		}, | 
 | 		"StraddlePallocChunkPages*2": { | 
 | 			npages: PallocChunkPages * 2, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, PallocChunkPages/2), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages / 2}}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 				BaseChunkIdx + 2: {{PallocChunkPages / 2, PallocChunkPages / 2}}, | 
 | 			}, | 
 | 		}, | 
 | 		"AllFreePallocChunkPages*7+5": { | 
 | 			npages: PallocChunkPages*7 + 5, | 
 | 			before: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 1: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 2: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 3: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 4: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 5: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 6: {{0, PallocChunkPages}}, | 
 | 				BaseChunkIdx + 7: {{0, PallocChunkPages}}, | 
 | 			}, | 
 | 			frees: []uintptr{ | 
 | 				PageBase(BaseChunkIdx, 0), | 
 | 			}, | 
 | 			after: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 				BaseChunkIdx + 2: {}, | 
 | 				BaseChunkIdx + 3: {}, | 
 | 				BaseChunkIdx + 4: {}, | 
 | 				BaseChunkIdx + 5: {}, | 
 | 				BaseChunkIdx + 6: {}, | 
 | 				BaseChunkIdx + 7: {{5, PallocChunkPages - 5}}, | 
 | 			}, | 
 | 		}, | 
 | 	} | 
 | 	for name, v := range tests { | 
 | 		v := v | 
 | 		t.Run(name, func(t *testing.T) { | 
 | 			b := NewPageAlloc(v.before, nil) | 
 | 			defer FreePageAlloc(b) | 
 |  | 
 | 			for _, addr := range v.frees { | 
 | 				b.Free(addr, v.npages) | 
 | 			} | 
 | 			want := NewPageAlloc(v.after, nil) | 
 | 			defer FreePageAlloc(want) | 
 |  | 
 | 			checkPageAlloc(t, want, b) | 
 | 		}) | 
 | 	} | 
 | } | 
 |  | 
 | func TestPageAllocAllocAndFree(t *testing.T) { | 
 | 	if GOOS == "openbsd" && testing.Short() { | 
 | 		t.Skip("skipping because virtual memory is limited; see #36210") | 
 | 	} | 
 | 	type hit struct { | 
 | 		alloc  bool | 
 | 		npages uintptr | 
 | 		base   uintptr | 
 | 	} | 
 | 	tests := map[string]struct { | 
 | 		init map[ChunkIdx][]BitRange | 
 | 		hits []hit | 
 | 	}{ | 
 | 		// TODO(mknyszek): Write more tests here. | 
 | 		"Chunks8": { | 
 | 			init: map[ChunkIdx][]BitRange{ | 
 | 				BaseChunkIdx:     {}, | 
 | 				BaseChunkIdx + 1: {}, | 
 | 				BaseChunkIdx + 2: {}, | 
 | 				BaseChunkIdx + 3: {}, | 
 | 				BaseChunkIdx + 4: {}, | 
 | 				BaseChunkIdx + 5: {}, | 
 | 				BaseChunkIdx + 6: {}, | 
 | 				BaseChunkIdx + 7: {}, | 
 | 			}, | 
 | 			hits: []hit{ | 
 | 				{true, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{false, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{true, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{false, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{true, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{false, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 				{true, 1, PageBase(BaseChunkIdx, 0)}, | 
 | 				{false, 1, PageBase(BaseChunkIdx, 0)}, | 
 | 				{true, PallocChunkPages * 8, PageBase(BaseChunkIdx, 0)}, | 
 | 			}, | 
 | 		}, | 
 | 	} | 
 | 	for name, v := range tests { | 
 | 		v := v | 
 | 		t.Run(name, func(t *testing.T) { | 
 | 			b := NewPageAlloc(v.init, nil) | 
 | 			defer FreePageAlloc(b) | 
 |  | 
 | 			for iter, i := range v.hits { | 
 | 				if i.alloc { | 
 | 					if a, _ := b.Alloc(i.npages); a != i.base { | 
 | 						t.Fatalf("bad alloc #%d: want 0x%x, got 0x%x", iter+1, i.base, a) | 
 | 					} | 
 | 				} else { | 
 | 					b.Free(i.base, i.npages) | 
 | 				} | 
 | 			} | 
 | 		}) | 
 | 	} | 
 | } |