08.10.2019 12:03, Max Reitz wrote:
> On 07.10.19 19:10, Vladimir Sementsov-Ogievskiy wrote:
>> 07.10.2019 18:27, Max Reitz wrote:
>>> On 03.10.19 19:15, Vladimir Sementsov-Ogievskiy wrote:
>>>> Currently total allocation for parallel requests to block-copy instance
>>>> is unlimited. Let's limit it to 128 MiB.
>>>>
>>>> For now block-copy is used only in backup, so actually we limit total
>>>> allocation for backup job.
>>>>
>>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
>>>> ---
>>>> include/block/block-copy.h | 3 +++
>>>> block/block-copy.c | 5 +++++
>>>> 2 files changed, 8 insertions(+)
>>>>
>>>> diff --git a/include/block/block-copy.h b/include/block/block-copy.h
>>>> index e2e135ff1b..bb666e7068 100644
>>>> --- a/include/block/block-copy.h
>>>> +++ b/include/block/block-copy.h
>>>> @@ -16,6 +16,7 @@
>>>> #define BLOCK_COPY_H
>>>>
>>>> #include "block/block.h"
>>>> +#include "qemu/co-shared-amount.h"
>>>>
>>>> typedef struct BlockCopyInFlightReq {
>>>> int64_t start_byte;
>>>> @@ -69,6 +70,8 @@ typedef struct BlockCopyState {
>>>> */
>>>> ProgressResetCallbackFunc progress_reset_callback;
>>>> void *progress_opaque;
>>>> +
>>>> + QemuCoSharedAmount *mem;
>>>> } BlockCopyState;
>>>>
>>>> BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild
>>>> *target,
>>>> diff --git a/block/block-copy.c b/block/block-copy.c
>>>> index cc49d2345d..e700c20d0f 100644
>>>> --- a/block/block-copy.c
>>>> +++ b/block/block-copy.c
>>>> @@ -21,6 +21,7 @@
>>>> #include "qemu/units.h"
>>>>
>>>> #define BLOCK_COPY_MAX_COPY_RANGE (16 * MiB)
>>>> +#define BLOCK_COPY_MAX_MEM (128 * MiB)
>>>>
>>>> static void coroutine_fn block_copy_wait_inflight_reqs(BlockCopyState
>>>> *s,
>>>> int64_t start,
>>>> @@ -64,6 +65,7 @@ void block_copy_state_free(BlockCopyState *s)
>>>> }
>>>>
>>>> bdrv_release_dirty_bitmap(s->source->bs, s->copy_bitmap);
>>>> + qemu_co_shared_amount_free(s->mem);
>>>> g_free(s);
>>>> }
>>>>
>>>> @@ -95,6 +97,7 @@ BlockCopyState *block_copy_state_new(BdrvChild *source,
>>>> BdrvChild *target,
>>>> .cluster_size = cluster_size,
>>>> .len = bdrv_dirty_bitmap_size(copy_bitmap),
>>>> .write_flags = write_flags,
>>>> + .mem = qemu_co_shared_amount_new(BLOCK_COPY_MAX_MEM),
>>>> };
>>>>
>>>> s->copy_range_size = QEMU_ALIGN_DOWN(max_transfer, cluster_size),
>>>> @@ -316,7 +319,9 @@ int coroutine_fn block_copy(BlockCopyState *s,
>>>>
>>>> bdrv_reset_dirty_bitmap(s->copy_bitmap, start, chunk_end -
>>>> start);
>>>>
>>>> + qemu_co_get_amount(s->mem, chunk_end - start);
>>>
>>> Now that I see it like this, maybe the name is too short. This sounds
>>> like it was trying to get some amount of coroutines.
>>>
>>> Would “qemu_co_get_from_shared_amount” be too long? (Something like
>>> qemu_co_sham_alloc() would be funny, but maybe not. :-) Or maybe
>>> exactly because it”s funny.)
>>>
>>
>> hmm sham may be interpreted as shared memory, not only like shame..
>
> “sham” is also a word by itself. :-)
Hmm didn't know, me go to google translate. OK, sham looks a lot nicer than
shame)
>
>> And if we call it _alloc, the opposite should be _free, but how to
>> distinguish it from freeing the whole object? Hmm, use create/destroy for
>> the whole object maybe.
>>
>> May be, drop "qemu_" ? It's not very informative. Or may be drop "co_"?.
>>
>> I don't like shaming my shared amount :)
>
> It’s worse calling it all a sham.
>
>> May be, we should imagine, what are we allocating? May be balls?
>>
>> struct BallAllocator
>>
>> ball_allocator_create
>> ball_allocator_destroy
>>
>> co_try_alloc_balls
>> co_alloc_balls
>> co_free_balls
>>
>> Or bars? Or which thing may be used for funny naming and to not intersect
>> with existing concepts like memory?
>
> I love it (thanks for making my morning), but I fear it may be
> interpreted as risqué.
>
> Maybe just shres for shared resource? So alloc_from_shres?
>
OK for me. But.. How to name _free function than?
struct SharedResource
shres_create
shres_destroy
co_try_alloc_from_shres
co_alloc_from_shres
co_free_???
co_free_res_alloced_from_shres ? :)
or
co_try_get_from_shres
co_get_from_shres
co_put_to_shres
>>>
>>>> ret = block_copy_do_copy(s, start, chunk_end, error_is_read);
>>>> + qemu_co_put_amount(s->mem, chunk_end - start);
>>>> if (ret < 0) {
>>>> bdrv_set_dirty_bitmap(s->copy_bitmap, start, chunk_end -
>>>> start);
>>>> break;
>>>>
>>>
>>>
>>
>>
>
>
--
Best regards,
Vladimir
