On 05/06/2015 10:20 PM, Wen Congyang wrote:
> On 05/02/2015 12:47 AM, John Snow wrote:
>>
>>
>> On 04/03/2015 07:05 AM, Paolo Bonzini wrote:
>>>
>>>
>>> On 03/04/2015 12:01, Wen Congyang wrote:
>>>> Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
>>>> Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
>>>> Signed-off-by: Gonglei <arei.gong...@huawei.com>
>>>> ---
>>>> include/qemu/hbitmap.h | 8 ++++++++
>>>> tests/test-hbitmap.c | 39 +++++++++++++++++++++++++++++++++++++++
>>>> util/hbitmap.c | 16 ++++++++++++++++
>>>> 3 files changed, 63 insertions(+)
>>>>
>>>> diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h
>>>> index 550d7ce..95a55e4 100644
>>>> --- a/include/qemu/hbitmap.h
>>>> +++ b/include/qemu/hbitmap.h
>>>> @@ -109,6 +109,14 @@ void hbitmap_set(HBitmap *hb, uint64_t start,
>>>> uint64_t count);
>>>> void hbitmap_reset(HBitmap *hb, uint64_t start, uint64_t count);
>>>>
>>>> /**
>>>> + * hbitmap_reset_all:
>>>> + * @hb: HBitmap to operate on.
>>>> + *
>>>> + * Reset all bits in an HBitmap.
>>>> + */
>>>> +void hbitmap_reset_all(HBitmap *hb);
>>>> +
>>>> +/**
>>>> * hbitmap_get:
>>>> * @hb: HBitmap to operate on.
>>>> * @item: Bit to query (0-based).
>>>> diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
>>>> index 8c902f2..1f0078a 100644
>>>> --- a/tests/test-hbitmap.c
>>>> +++ b/tests/test-hbitmap.c
>>>> @@ -11,6 +11,7 @@
>>>>
>>>> #include <glib.h>
>>>> #include <stdarg.h>
>>>> +#include <string.h>
>>>> #include "qemu/hbitmap.h"
>>>>
>>>> #define LOG_BITS_PER_LONG (BITS_PER_LONG == 32 ? 5 : 6)
>>>> @@ -143,6 +144,23 @@ static void hbitmap_test_reset(TestHBitmapData *data,
>>>> }
>>>> }
>>>>
>>>> +static void hbitmap_test_reset_all(TestHBitmapData *data)
>>>> +{
>>>> + size_t n;
>>>> +
>>>> + hbitmap_reset_all(data->hb);
>>>> +
>>>> + n = (data->size + BITS_PER_LONG - 1) / BITS_PER_LONG;
>>>> + if (n == 0) {
>>>> + n = 1;
>>>> + }
>>>> + memset(data->bits, 0, n * sizeof(unsigned long));
>>>> +
>>>> + if (data->granularity == 0) {
>>>> + hbitmap_test_check(data, 0);
>>>> + }
>>>> +}
>>>> +
>>>> static void hbitmap_test_check_get(TestHBitmapData *data)
>>>> {
>>>> uint64_t count = 0;
>>>> @@ -323,6 +341,26 @@ static void test_hbitmap_reset(TestHBitmapData *data,
>>>> hbitmap_test_set(data, L3 / 2, L3);
>>>> }
>>>>
>>>> +static void test_hbitmap_reset_all(TestHBitmapData *data,
>>>> + const void *unused)
>>>> +{
>>>> + hbitmap_test_init(data, L3 * 2, 0);
>>>> + hbitmap_test_set(data, L1 - 1, L1 + 2);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, 0, L1 * 3);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, L2, L1);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, L2, L3 - L2 + 1);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, L3 - 1, 3);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, 0, L3 * 2);
>>>> + hbitmap_test_reset_all(data);
>>>> + hbitmap_test_set(data, L3 / 2, L3);
>>>> + hbitmap_test_reset_all(data);
>>>> +}
>>>> +
>>>> static void test_hbitmap_granularity(TestHBitmapData *data,
>>>> const void *unused)
>>>> {
>>>> @@ -394,6 +432,7 @@ int main(int argc, char **argv)
>>>> hbitmap_test_add("/hbitmap/set/overlap", test_hbitmap_set_overlap);
>>>> hbitmap_test_add("/hbitmap/reset/empty", test_hbitmap_reset_empty);
>>>> hbitmap_test_add("/hbitmap/reset/general", test_hbitmap_reset);
>>>> + hbitmap_test_add("/hbitmap/reset/all", test_hbitmap_reset_all);
>>>> hbitmap_test_add("/hbitmap/granularity", test_hbitmap_granularity);
>>>> g_test_run();
>>>>
>>>> diff --git a/util/hbitmap.c b/util/hbitmap.c
>>>> index ab13971..acce93c 100644
>>>> --- a/util/hbitmap.c
>>>> +++ b/util/hbitmap.c
>>>> @@ -353,6 +353,22 @@ void hbitmap_reset(HBitmap *hb, uint64_t start,
>>>> uint64_t count)
>>>> hb_reset_between(hb, HBITMAP_LEVELS - 1, start, last);
>>>> }
>>>>
>>>> +void hbitmap_reset_all(HBitmap *hb)
>>>> +{
>>>> + uint64_t size = hb->size;
>>>> + unsigned int i;
>>>> +
>>>> + /* Same as hbitmap_alloc() except memset() */
>>>> + for (i = HBITMAP_LEVELS; --i >= 1; ) {
>>>> + size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1);
>>>> + memset(hb->levels[i], 0, size * sizeof(unsigned long));
>>>> + }
>>>> +
>>
>> For what it's worth, I recently added in a hb->sizes[i] cache to store the
>> size of each array so you don't have to recompute this all the time.
>
> Yes, will fix it in the next version.
>
> Thanks
> Wen Congyang
>
Since the reset stuff is useful all by itself, you can send that patch
by itself, CC me, and I'll review it.
You can update the existing call in block.c:
bdrv_clear_dirty_bitmap() {
hbitmap_reset(bitmap->bitmap, 0, bitmap->size);
}
to using your faster hbitmap_reset_all call.
Thanks,
--js
>>
>>>> + assert(size == 1);
>>>> + hb->levels[0][0] = 1UL << (BITS_PER_LONG - 1);
>>>> + hb->count = 0;
>>>> +}
>>>> +
>>>> bool hbitmap_get(const HBitmap *hb, uint64_t item)
>>>> {
>>>> /* Compute position and bit in the last layer. */
>>>>
>>>
>>> Acked-by: Paolo Bonzini <pbonz...@redhat.com>
>>>
>> .
>>
>
>
