96e4dedaff
This patch adds two new fields to BlockDeviceTimedStats that track the average number of pending read and write requests for a block device. The values are calculated for the period of time defined for that interval. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: fd31fef53e2714f2f30d59ed58ca2f67ec9ab926.1446044837.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
65 lines
2.3 KiB
C
65 lines
2.3 KiB
C
/*
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* QEMU timed average computation
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*
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* Copyright (C) Nodalink, EURL. 2014
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* Copyright (C) Igalia, S.L. 2015
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*
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* Authors:
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* Benoît Canet <benoit.canet@nodalink.com>
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* Alberto Garcia <berto@igalia.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) version 3 or any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef TIMED_AVERAGE_H
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#define TIMED_AVERAGE_H
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#include <stdint.h>
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#include "qemu/timer.h"
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typedef struct TimedAverageWindow TimedAverageWindow;
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typedef struct TimedAverage TimedAverage;
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/* All fields of both structures are private */
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struct TimedAverageWindow {
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uint64_t min; /* minimum value accounted in the window */
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uint64_t max; /* maximum value accounted in the window */
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uint64_t sum; /* sum of all values */
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uint64_t count; /* number of values */
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int64_t expiration; /* the end of the current window in ns */
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};
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struct TimedAverage {
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uint64_t period; /* period in nanoseconds */
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TimedAverageWindow windows[2]; /* two overlapping windows of with
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* an offset of period / 2 between them */
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unsigned current; /* the current window index: it's also the
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* oldest window index */
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QEMUClockType clock_type; /* the clock used */
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};
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void timed_average_init(TimedAverage *ta, QEMUClockType clock_type,
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uint64_t period);
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void timed_average_account(TimedAverage *ta, uint64_t value);
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uint64_t timed_average_min(TimedAverage *ta);
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uint64_t timed_average_avg(TimedAverage *ta);
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uint64_t timed_average_max(TimedAverage *ta);
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uint64_t timed_average_sum(TimedAverage *ta, uint64_t *elapsed);
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#endif
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