| Message ID | 1453270306-16608-7-git-send-email-famz@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/20/2016 01:11 AM, Fam Zheng wrote: > Upon each bit toggle, the corresponding bit in the meta bitmap will be > set. > > Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> > --- > include/qemu/hbitmap.h | 17 +++++++++++++ > util/hbitmap.c | 66 ++++++++++++++++++++++++++++++++++++++------------ > 2 files changed, 68 insertions(+), 15 deletions(-) > > diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h > index bb94a00..595ad65 100644 > --- a/include/qemu/hbitmap.h > +++ b/include/qemu/hbitmap.h > @@ -181,6 +181,23 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first); > */ > unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi); > > +/* hbitmap_create_meta: > + * Create a "meta" hbitmap to track dirtiness of the bits in this HBitmap. > + * The caller owns the created bitmap and must call hbitmap_free_meta(hb) to > + * free it. > + * > + * @hb: The HBitmap to operate on. > + * @chunk_size: How many bits in @hb does one bit in the meta track. > + */ > +HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size); > + > +/* hbitmap_free_meta: > + * Free the meta bitmap of @hb. > + * > + * @hb: The HBitmap whose meta bitmap should be freed. > + */ > +void hbitmap_free_meta(HBitmap *hb); > + > /** > * hbitmap_iter_next: > * @hbi: HBitmapIter to operate on. > diff --git a/util/hbitmap.c b/util/hbitmap.c > index 50b888f..79f6236 100644 > --- a/util/hbitmap.c > +++ b/util/hbitmap.c > @@ -81,6 +81,9 @@ struct HBitmap { > */ > int granularity; > > + /* A meta dirty bitmap to track the dirtiness of bits in this HBitmap. */ > + HBitmap *meta; > + > /* A number of progressively less coarse bitmaps (i.e. level 0 is the > * coarsest). Each bit in level N represents a word in level N+1 that > * has a set bit, except the last level where each bit represents the > @@ -212,25 +215,27 @@ static uint64_t hb_count_between(HBitmap *hb, uint64_t start, uint64_t last) > } > > /* Setting starts at the last layer and propagates up if an element > - * changes from zero to non-zero. > + * changes. > */ > static inline bool hb_set_elem(unsigned long *elem, uint64_t start, uint64_t last) > { > unsigned long mask; > - bool changed; > + unsigned long old; > > assert((last >> BITS_PER_LEVEL) == (start >> BITS_PER_LEVEL)); > assert(start <= last); > > mask = 2UL << (last & (BITS_PER_LONG - 1)); > mask -= 1UL << (start & (BITS_PER_LONG - 1)); > - changed = (*elem == 0); > + old = *elem; > *elem |= mask; > - return changed; > + return old != *elem; > } > > -/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... */ > -static void hb_set_between(HBitmap *hb, int level, uint64_t start, uint64_t last) > +/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... > + * Returns true if at least one bit is changed. */ > +static bool hb_set_between(HBitmap *hb, int level, uint64_t start, > + uint64_t last) > { > size_t pos = start >> BITS_PER_LEVEL; > size_t lastpos = last >> BITS_PER_LEVEL; > @@ -259,22 +264,27 @@ static void hb_set_between(HBitmap *hb, int level, uint64_t start, uint64_t last > if (level > 0 && changed) { > hb_set_between(hb, level - 1, pos, lastpos); > } > + return changed; > } > > void hbitmap_set(HBitmap *hb, uint64_t start, uint64_t count) > { > /* Compute range in the last layer. */ > + uint64_t first, n; > uint64_t last = start + count - 1; > > trace_hbitmap_set(hb, start, count, > start >> hb->granularity, last >> hb->granularity); > > - start >>= hb->granularity; > + first = start >> hb->granularity; > last >>= hb->granularity; > - count = last - start + 1; > + n = last - first + 1; > > - hb->count += count - hb_count_between(hb, start, last); > - hb_set_between(hb, HBITMAP_LEVELS - 1, start, last); > + hb->count += n - hb_count_between(hb, first, last); > + if (hb_set_between(hb, HBITMAP_LEVELS - 1, first, last) && > + hb->meta) { > + hbitmap_set(hb->meta, start, count); > + } > } > > /* Resetting works the other way round: propagate up if the new > @@ -295,8 +305,10 @@ static inline bool hb_reset_elem(unsigned long *elem, uint64_t start, uint64_t l > return blanked; > } > > -/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... */ > -static void hb_reset_between(HBitmap *hb, int level, uint64_t start, uint64_t last) > +/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... > + * Returns true if at least one bit is changed. */ > +static bool hb_reset_between(HBitmap *hb, int level, uint64_t start, > + uint64_t last) > { > size_t pos = start >> BITS_PER_LEVEL; > size_t lastpos = last >> BITS_PER_LEVEL; > @@ -339,21 +351,28 @@ static void hb_reset_between(HBitmap *hb, int level, uint64_t start, uint64_t la > if (level > 0 && changed) { > hb_reset_between(hb, level - 1, pos, lastpos); > } > + > + return changed; > + > } > > void hbitmap_reset(HBitmap *hb, uint64_t start, uint64_t count) > { > /* Compute range in the last layer. */ > + uint64_t first; > uint64_t last = start + count - 1; > > trace_hbitmap_reset(hb, start, count, > start >> hb->granularity, last >> hb->granularity); > > - start >>= hb->granularity; > + first = start >> hb->granularity; > last >>= hb->granularity; > > - hb->count -= hb_count_between(hb, start, last); > - hb_reset_between(hb, HBITMAP_LEVELS - 1, start, last); > + hb->count -= hb_count_between(hb, first, last); > + if (hb_reset_between(hb, HBITMAP_LEVELS - 1, first, last) && > + hb->meta) { > + hbitmap_set(hb->meta, start, count); > + } > } > > void hbitmap_reset_all(HBitmap *hb) > @@ -381,6 +400,7 @@ bool hbitmap_get(const HBitmap *hb, uint64_t item) > void hbitmap_free(HBitmap *hb) > { > unsigned i; > + assert(!hb->meta); > for (i = HBITMAP_LEVELS; i-- > 0; ) { > g_free(hb->levels[i]); > } > @@ -493,3 +513,19 @@ bool hbitmap_merge(HBitmap *a, const HBitmap *b) > > return true; > } > + > +HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size) > +{ > + assert(!(chunk_size & (chunk_size - 1))); > + assert(!hb->meta); > + hb->meta = hbitmap_alloc(hb->size << hb->granularity, > + hb->granularity + ctz32(chunk_size)); > + return hb->meta; > +} > + > +void hbitmap_free_meta(HBitmap *hb) > +{ > + assert(hb->meta); > + hbitmap_free(hb->meta); > + hb->meta = NULL; > +} >
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index bb94a00..595ad65 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -181,6 +181,23 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first); */ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi); +/* hbitmap_create_meta: + * Create a "meta" hbitmap to track dirtiness of the bits in this HBitmap. + * The caller owns the created bitmap and must call hbitmap_free_meta(hb) to + * free it. + * + * @hb: The HBitmap to operate on. + * @chunk_size: How many bits in @hb does one bit in the meta track. + */ +HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size); + +/* hbitmap_free_meta: + * Free the meta bitmap of @hb. + * + * @hb: The HBitmap whose meta bitmap should be freed. + */ +void hbitmap_free_meta(HBitmap *hb); + /** * hbitmap_iter_next: * @hbi: HBitmapIter to operate on. diff --git a/util/hbitmap.c b/util/hbitmap.c index 50b888f..79f6236 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -81,6 +81,9 @@ struct HBitmap { */ int granularity; + /* A meta dirty bitmap to track the dirtiness of bits in this HBitmap. */ + HBitmap *meta; + /* A number of progressively less coarse bitmaps (i.e. level 0 is the * coarsest). Each bit in level N represents a word in level N+1 that * has a set bit, except the last level where each bit represents the @@ -212,25 +215,27 @@ static uint64_t hb_count_between(HBitmap *hb, uint64_t start, uint64_t last) } /* Setting starts at the last layer and propagates up if an element - * changes from zero to non-zero. + * changes. */ static inline bool hb_set_elem(unsigned long *elem, uint64_t start, uint64_t last) { unsigned long mask; - bool changed; + unsigned long old; assert((last >> BITS_PER_LEVEL) == (start >> BITS_PER_LEVEL)); assert(start <= last); mask = 2UL << (last & (BITS_PER_LONG - 1)); mask -= 1UL << (start & (BITS_PER_LONG - 1)); - changed = (*elem == 0); + old = *elem; *elem |= mask; - return changed; + return old != *elem; } -/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... */ -static void hb_set_between(HBitmap *hb, int level, uint64_t start, uint64_t last) +/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... + * Returns true if at least one bit is changed. */ +static bool hb_set_between(HBitmap *hb, int level, uint64_t start, + uint64_t last) { size_t pos = start >> BITS_PER_LEVEL; size_t lastpos = last >> BITS_PER_LEVEL; @@ -259,22 +264,27 @@ static void hb_set_between(HBitmap *hb, int level, uint64_t start, uint64_t last if (level > 0 && changed) { hb_set_between(hb, level - 1, pos, lastpos); } + return changed; } void hbitmap_set(HBitmap *hb, uint64_t start, uint64_t count) { /* Compute range in the last layer. */ + uint64_t first, n; uint64_t last = start + count - 1; trace_hbitmap_set(hb, start, count, start >> hb->granularity, last >> hb->granularity); - start >>= hb->granularity; + first = start >> hb->granularity; last >>= hb->granularity; - count = last - start + 1; + n = last - first + 1; - hb->count += count - hb_count_between(hb, start, last); - hb_set_between(hb, HBITMAP_LEVELS - 1, start, last); + hb->count += n - hb_count_between(hb, first, last); + if (hb_set_between(hb, HBITMAP_LEVELS - 1, first, last) && + hb->meta) { + hbitmap_set(hb->meta, start, count); + } } /* Resetting works the other way round: propagate up if the new @@ -295,8 +305,10 @@ static inline bool hb_reset_elem(unsigned long *elem, uint64_t start, uint64_t l return blanked; } -/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... */ -static void hb_reset_between(HBitmap *hb, int level, uint64_t start, uint64_t last) +/* The recursive workhorse (the depth is limited to HBITMAP_LEVELS)... + * Returns true if at least one bit is changed. */ +static bool hb_reset_between(HBitmap *hb, int level, uint64_t start, + uint64_t last) { size_t pos = start >> BITS_PER_LEVEL; size_t lastpos = last >> BITS_PER_LEVEL; @@ -339,21 +351,28 @@ static void hb_reset_between(HBitmap *hb, int level, uint64_t start, uint64_t la if (level > 0 && changed) { hb_reset_between(hb, level - 1, pos, lastpos); } + + return changed; + } void hbitmap_reset(HBitmap *hb, uint64_t start, uint64_t count) { /* Compute range in the last layer. */ + uint64_t first; uint64_t last = start + count - 1; trace_hbitmap_reset(hb, start, count, start >> hb->granularity, last >> hb->granularity); - start >>= hb->granularity; + first = start >> hb->granularity; last >>= hb->granularity; - hb->count -= hb_count_between(hb, start, last); - hb_reset_between(hb, HBITMAP_LEVELS - 1, start, last); + hb->count -= hb_count_between(hb, first, last); + if (hb_reset_between(hb, HBITMAP_LEVELS - 1, first, last) && + hb->meta) { + hbitmap_set(hb->meta, start, count); + } } void hbitmap_reset_all(HBitmap *hb) @@ -381,6 +400,7 @@ bool hbitmap_get(const HBitmap *hb, uint64_t item) void hbitmap_free(HBitmap *hb) { unsigned i; + assert(!hb->meta); for (i = HBITMAP_LEVELS; i-- > 0; ) { g_free(hb->levels[i]); } @@ -493,3 +513,19 @@ bool hbitmap_merge(HBitmap *a, const HBitmap *b) return true; } + +HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size) +{ + assert(!(chunk_size & (chunk_size - 1))); + assert(!hb->meta); + hb->meta = hbitmap_alloc(hb->size << hb->granularity, + hb->granularity + ctz32(chunk_size)); + return hb->meta; +} + +void hbitmap_free_meta(HBitmap *hb) +{ + assert(hb->meta); + hbitmap_free(hb->meta); + hb->meta = NULL; +}
Upon each bit toggle, the corresponding bit in the meta bitmap will be set. Signed-off-by: Fam Zheng <famz@redhat.com> --- include/qemu/hbitmap.h | 17 +++++++++++++ util/hbitmap.c | 66 ++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 68 insertions(+), 15 deletions(-)