qemu/block/accounting.c
Max Reitz 53d8f9d8fb block: Remove wr_highest_sector from BlockAcctStats
BlockAcctStats contains statistics about the data transferred from and
to the device; wr_highest_sector does not fit in with the rest.

Furthermore, those statistics are supposed to be specific for a certain
device and not necessarily for a BDS (see the comment above
bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather
important information to know for each BDS. When BlockAcctStats is
finally removed from the BDS, we will want to keep wr_highest_sector in
the BDS.

Finally, wr_highest_sector is renamed to wr_highest_offset and given the
appropriate meaning. Externally, it is represented as an offset so there
is no point in doing something different internally. Its definition is
changed to match that in qapi/block-core.json which is "the offset after
the greatest byte written to". Doing so should not cause any harm since
if external programs tried to calculate the volume usage by
(wr_highest_offset + 512) / volume_size, after this patch they will just
assume the volume to be full slightly earlier than before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00

56 lines
2.0 KiB
C

/*
* QEMU System Emulator block accounting
*
* Copyright (c) 2011 Christoph Hellwig
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "block/accounting.h"
#include "block/block_int.h"
#include "qemu/timer.h"
void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
int64_t bytes, enum BlockAcctType type)
{
assert(type < BLOCK_MAX_IOTYPE);
cookie->bytes = bytes;
cookie->start_time_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
cookie->type = type;
}
void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
{
assert(cookie->type < BLOCK_MAX_IOTYPE);
stats->nr_bytes[cookie->type] += cookie->bytes;
stats->nr_ops[cookie->type]++;
stats->total_time_ns[cookie->type] +=
qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - cookie->start_time_ns;
}
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests)
{
assert(type < BLOCK_MAX_IOTYPE);
stats->merged[type] += num_requests;
}