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https://gitlab.isc.org/isc-projects/bind9
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25daa047d4
Qpzone employs a locking strategy where rwlocks are grouped into buckets, and each zone gets 17 buckets. This strategy is suboptimal in two ways: - If named is serving a single zone or a zone is the majority of the traffic, this strategy pretty much guarantees contention when using more than a dozen threads. - If named is serving many small zones, it causes substantial memory usage. This commit switches the locking to a global table initialized at start time. This should have three effects: - Performance should improve in the single zone case, since now we are selecting from a bigger pool of locks. - Memory consumption should go down significantly in the many zone cases. - Performance should not degrade substantially in the many zone cases. The reason for this is that, while we could have substantially more zones than locks, we can query/edit only O(num threads) at the same time. So by making the global table much bigger than the expected number of threads, we can limit contention.
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/*
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* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
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*
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* SPDX-License-Identifier: MPL-2.0
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, you can obtain one at https://mozilla.org/MPL/2.0/.
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*
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* See the COPYRIGHT file distributed with this work for additional
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* information regarding copyright ownership.
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*/
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#pragma once
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#include <isc/heap.h>
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#include <isc/rwlock.h>
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#include <isc/urcu.h>
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#include <dns/nsec3.h>
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#include <dns/qp.h>
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#include <dns/types.h>
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/*****
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***** Module Info
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*****/
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/*! \file
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* \brief
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* DNS QP-Trie DB Implementation
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*/
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isc_result_t
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dns__qpzone_create(isc_mem_t *mctx, const dns_name_t *base, dns_dbtype_t type,
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dns_rdataclass_t rdclass, unsigned int argc, char **argv,
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void *driverarg, dns_db_t **dbp);
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/*%<
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* Create a new database of type "qpzone". Called via dns_db_create();
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* see documentation for that function for more details.
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*
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* If argv[0] is set, it points to a valid memory context to be used for
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* allocation of heap memory. Generally this is used for cache databases
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* only.
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*
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* Requires:
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*
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* \li argc == 0 or argv[0] is a valid memory context.
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*/
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void
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dns__qpzone_initialize(void);
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void
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dns__qpzone_shutdown(void);
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