mirror_zfs/include/sys/dmu_tx.h
lidongyang 823d48bfb1 Call commit callbacks from the tail of the list
Our zfs backed Lustre MDT had soft lockups while under heavy metadata
workloads while handling transaction callbacks from osd_zfs.

The problem is zfs is not taking advantage of the fast path in
Lustre's trans callback handling, where Lustre will skip the calls
to ptlrpc_commit_replies() when it already saw a higher transaction
number.

This patch corrects this, it also has a positive impact on metadata
performance on Lustre with osd_zfs, plus some cleanup in the headers.

A similar issue for ext4/ldiskfs is described on:
https://jira.hpdd.intel.com/browse/LU-6527

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Li Dongyang <dongyang.li@anu.edu.au>
Closes #6986
2017-12-22 10:19:51 -08:00

177 lines
4.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2012, 2016 by Delphix. All rights reserved.
*/
#ifndef _SYS_DMU_TX_H
#define _SYS_DMU_TX_H
#include <sys/inttypes.h>
#include <sys/dmu.h>
#include <sys/txg.h>
#include <sys/refcount.h>
#ifdef __cplusplus
extern "C" {
#endif
struct dmu_buf_impl;
struct dmu_tx_hold;
struct dnode_link;
struct dsl_pool;
struct dnode;
struct dsl_dir;
struct dmu_tx {
/*
* No synchronization is needed because a tx can only be handled
* by one thread.
*/
list_t tx_holds; /* list of dmu_tx_hold_t */
objset_t *tx_objset;
struct dsl_dir *tx_dir;
struct dsl_pool *tx_pool;
uint64_t tx_txg;
uint64_t tx_lastsnap_txg;
uint64_t tx_lasttried_txg;
txg_handle_t tx_txgh;
void *tx_tempreserve_cookie;
struct dmu_tx_hold *tx_needassign_txh;
/* list of dmu_tx_callback_t on this dmu_tx */
list_t tx_callbacks;
/* placeholder for syncing context, doesn't need specific holds */
boolean_t tx_anyobj;
/* has this transaction already been delayed? */
boolean_t tx_waited;
/* transaction is marked as being a "net free" of space */
boolean_t tx_netfree;
/* time this transaction was created */
hrtime_t tx_start;
/* need to wait for sufficient dirty space */
boolean_t tx_wait_dirty;
int tx_err;
};
enum dmu_tx_hold_type {
THT_NEWOBJECT,
THT_WRITE,
THT_BONUS,
THT_FREE,
THT_ZAP,
THT_SPACE,
THT_SPILL,
THT_NUMTYPES
};
typedef struct dmu_tx_hold {
dmu_tx_t *txh_tx;
list_node_t txh_node;
struct dnode *txh_dnode;
refcount_t txh_space_towrite;
refcount_t txh_memory_tohold;
enum dmu_tx_hold_type txh_type;
uint64_t txh_arg1;
uint64_t txh_arg2;
} dmu_tx_hold_t;
typedef struct dmu_tx_callback {
list_node_t dcb_node; /* linked to tx_callbacks list */
dmu_tx_callback_func_t *dcb_func; /* caller function pointer */
void *dcb_data; /* caller private data */
} dmu_tx_callback_t;
/*
* Used for dmu tx kstat.
*/
typedef struct dmu_tx_stats {
kstat_named_t dmu_tx_assigned;
kstat_named_t dmu_tx_delay;
kstat_named_t dmu_tx_error;
kstat_named_t dmu_tx_suspended;
kstat_named_t dmu_tx_group;
kstat_named_t dmu_tx_memory_reserve;
kstat_named_t dmu_tx_memory_reclaim;
kstat_named_t dmu_tx_dirty_throttle;
kstat_named_t dmu_tx_dirty_delay;
kstat_named_t dmu_tx_dirty_over_max;
kstat_named_t dmu_tx_quota;
} dmu_tx_stats_t;
extern dmu_tx_stats_t dmu_tx_stats;
#define DMU_TX_STAT_INCR(stat, val) \
atomic_add_64(&dmu_tx_stats.stat.value.ui64, (val));
#define DMU_TX_STAT_BUMP(stat) \
DMU_TX_STAT_INCR(stat, 1);
/*
* These routines are defined in dmu.h, and are called by the user.
*/
dmu_tx_t *dmu_tx_create(objset_t *dd);
int dmu_tx_assign(dmu_tx_t *tx, txg_how_t txg_how);
void dmu_tx_commit(dmu_tx_t *tx);
void dmu_tx_abort(dmu_tx_t *tx);
uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
struct dsl_pool *dmu_tx_pool(dmu_tx_t *tx);
void dmu_tx_wait(dmu_tx_t *tx);
/*
* These routines are defined in dmu_spa.h, and are called by the SPA.
*/
extern dmu_tx_t *dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg);
/*
* These routines are only called by the DMU.
*/
dmu_tx_t *dmu_tx_create_dd(dsl_dir_t *dd);
int dmu_tx_is_syncing(dmu_tx_t *tx);
int dmu_tx_private_ok(dmu_tx_t *tx);
void dmu_tx_add_new_object(dmu_tx_t *tx, dnode_t *dn);
void dmu_tx_dirty_buf(dmu_tx_t *tx, struct dmu_buf_impl *db);
void dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space);
#ifdef ZFS_DEBUG
#define DMU_TX_DIRTY_BUF(tx, db) dmu_tx_dirty_buf(tx, db)
#else
#define DMU_TX_DIRTY_BUF(tx, db)
#endif
void dmu_tx_init(void);
void dmu_tx_fini(void);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_DMU_TX_H */