From a33fbb4f8b64226becf502a123733776ce319b24 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 13 Jun 2018 20:18:16 +0200 Subject: [PATCH] hbitmap: Add @advance param to hbitmap_iter_next() This new parameter allows the caller to just query the next dirty position without moving the iterator. Signed-off-by: Max Reitz Reviewed-by: Fam Zheng Reviewed-by: John Snow Message-id: 20180613181823.13618-8-mreitz@redhat.com Signed-off-by: Max Reitz --- block/backup.c | 2 +- block/dirty-bitmap.c | 2 +- include/qemu/hbitmap.h | 5 ++++- tests/test-hbitmap.c | 26 +++++++++++++------------- util/hbitmap.c | 10 +++++++--- 5 files changed, 26 insertions(+), 19 deletions(-) diff --git a/block/backup.c b/block/backup.c index 5661435675..d18be40caf 100644 --- a/block/backup.c +++ b/block/backup.c @@ -354,7 +354,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job) HBitmapIter hbi; hbitmap_iter_init(&hbi, job->copy_bitmap, 0); - while ((cluster = hbitmap_iter_next(&hbi)) != -1) { + while ((cluster = hbitmap_iter_next(&hbi, true)) != -1) { do { if (yield_and_check(job)) { return 0; diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 383d742cdb..cedb971765 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -519,7 +519,7 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter) int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter) { - return hbitmap_iter_next(&iter->hbi); + return hbitmap_iter_next(&iter->hbi, true); } /* Called within bdrv_dirty_bitmap_lock..unlock */ diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 6b6490ecad..ddca52c48e 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -324,11 +324,14 @@ void hbitmap_free_meta(HBitmap *hb); /** * hbitmap_iter_next: * @hbi: HBitmapIter to operate on. + * @advance: If true, advance the iterator. Otherwise, the next call + * of this function will return the same result (if that + * position is still dirty). * * Return the next bit that is set in @hbi's associated HBitmap, * or -1 if all remaining bits are zero. */ -int64_t hbitmap_iter_next(HBitmapIter *hbi); +int64_t hbitmap_iter_next(HBitmapIter *hbi, bool advance); /** * hbitmap_iter_next_word: diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c index f29631f939..f2158f767d 100644 --- a/tests/test-hbitmap.c +++ b/tests/test-hbitmap.c @@ -46,7 +46,7 @@ static void hbitmap_test_check(TestHBitmapData *data, i = first; for (;;) { - next = hbitmap_iter_next(&hbi); + next = hbitmap_iter_next(&hbi, true); if (next < 0) { next = data->size; } @@ -435,25 +435,25 @@ static void test_hbitmap_iter_granularity(TestHBitmapData *data, /* Note that hbitmap_test_check has to be invoked manually in this test. */ hbitmap_test_init(data, 131072 << 7, 7); hbitmap_iter_init(&hbi, data->hb, 0); - g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0); hbitmap_test_set(data, ((L2 + L1 + 1) << 7) + 8, 8); hbitmap_iter_init(&hbi, data->hb, 0); - g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, (L2 + L1 + 1) << 7); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0); hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0); hbitmap_test_set(data, (131072 << 7) - 8, 8); hbitmap_iter_init(&hbi, data->hb, 0); - g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, (L2 + L1 + 1) << 7); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, 131071 << 7); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0); hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7); - g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, 131071 << 7); + g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0); } static void hbitmap_test_set_boundary_bits(TestHBitmapData *data, ssize_t diff) @@ -893,7 +893,7 @@ static void test_hbitmap_serialize_zeroes(TestHBitmapData *data, for (i = 0; i < num_positions; i++) { hbitmap_deserialize_zeroes(data->hb, positions[i], min_l1, true); hbitmap_iter_init(&iter, data->hb, 0); - next = hbitmap_iter_next(&iter); + next = hbitmap_iter_next(&iter, true); if (i == num_positions - 1) { g_assert_cmpint(next, ==, -1); } else { @@ -919,10 +919,10 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData *data, hbitmap_iter_init(&hbi, data->hb, BITS_PER_LONG - 1); - hbitmap_iter_next(&hbi); + hbitmap_iter_next(&hbi, true); hbitmap_reset_all(data->hb); - hbitmap_iter_next(&hbi); + hbitmap_iter_next(&hbi, true); } static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start) diff --git a/util/hbitmap.c b/util/hbitmap.c index 58a2c93842..bcd304041a 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -141,7 +141,7 @@ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi) return cur; } -int64_t hbitmap_iter_next(HBitmapIter *hbi) +int64_t hbitmap_iter_next(HBitmapIter *hbi, bool advance) { unsigned long cur = hbi->cur[HBITMAP_LEVELS - 1] & hbi->hb->levels[HBITMAP_LEVELS - 1][hbi->pos]; @@ -154,8 +154,12 @@ int64_t hbitmap_iter_next(HBitmapIter *hbi) } } - /* The next call will resume work from the next bit. */ - hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1); + if (advance) { + /* The next call will resume work from the next bit. */ + hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1); + } else { + hbi->cur[HBITMAP_LEVELS - 1] = cur; + } item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + ctzl(cur); return item << hbi->granularity;