Viewing: lustre_nrs_orr.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2014, Intel Corporation.
*
* Copyright 2012 Xyratex Technology Limited
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Network Request Scheduler (NRS) Object-based Round Robin and Target-based
* Round Robin (ORR and TRR) policies
*/
#ifndef _LUSTRE_NRS_ORR_H
#define _LUSTRE_NRS_ORR_H
#include <lustre_compat/linux/xarray.h>
/**
* ORR policy operations
*/
#define NRS_CTL_ORR_RD_QUANTUM PTLRPC_NRS_CTL_POL_SPEC_01
#define NRS_CTL_ORR_WR_QUANTUM PTLRPC_NRS_CTL_POL_SPEC_02
#define NRS_CTL_ORR_RD_OFF_TYPE PTLRPC_NRS_CTL_POL_SPEC_03
#define NRS_CTL_ORR_WR_OFF_TYPE PTLRPC_NRS_CTL_POL_SPEC_04
#define NRS_CTL_ORR_RD_SUPP_REQ PTLRPC_NRS_CTL_POL_SPEC_05
#define NRS_CTL_ORR_WR_SUPP_REQ PTLRPC_NRS_CTL_POL_SPEC_06
/**
* \name ORR/TRR
*
* ORR/TRR (Object-based Round Robin/Target-based Round Robin) NRS policies
* @{
*/
/**
* Lower and upper byte offsets of a brw RPC
*/
struct nrs_orr_req_range {
__u64 or_start;
__u64 or_end;
};
/**
* RPC types supported by the ORR/TRR policies
*/
enum nrs_orr_supp {
NOS_OST_READ = BIT(0),
NOS_OST_WRITE = BIT(1),
NOS_OST_RW = (NOS_OST_READ | NOS_OST_WRITE),
/**
* Default value for policies.
*/
NOS_DFLT = NOS_OST_READ
};
/**
* As unique keys for grouping RPCs together, we use the object's OST FID for
* the ORR policy, and the OST index for the TRR policy.
*
* XXX: We waste some space for TRR policy instances by using a union, but it
* allows to consolidate some of the code between ORR and TRR, and these
* policies will probably eventually merge into one anyway.
*/
struct nrs_orr_key {
union {
/** object FID for ORR */
struct lu_fid ok_fid;
/** OST index for TRR */
__u32 ok_idx;
};
};
/**
* The largest base string for unique hash/slab object names is
* "nrs_orr_reg_", so 13 characters. We add 3 to this to be used for the CPT
* id number, so this _should_ be more than enough for the maximum number of
* CPTs on any system. If it does happen that this statement is incorrect,
* nrs_orr_genobjname() will inevitably yield a non-unique name and cause
* kmem_cache_create() to complain (on Linux), so the erroneous situation
* will hopefully not go unnoticed.
*/
#define NRS_ORR_OBJ_NAME_MAX (sizeof("nrs_orr_reg_") + 3)
/**
* private data structure for ORR and TRR NRS
*/
struct nrs_orr_data {
struct ptlrpc_nrs_resource od_res;
struct binheap *od_binheap;
struct rhashtable od_obj_hash;
struct xarray od_trr_objs;
struct kmem_cache *od_cache;
/**
* Used when a new scheduling round commences, in order to synchronize
* all object or OST batches with the new round number.
*/
__u64 od_round;
/**
* Determines the relevant ordering amongst request batches within a
* scheduling round.
*/
__u64 od_sequence;
/**
* RPC types that are currently supported.
*/
enum nrs_orr_supp od_supp;
/**
* Round Robin quantum; the maxium number of RPCs that each request
* batch for each object or OST can have in a scheduling round.
*/
__u16 od_quantum;
/**
* Whether to use physical disk offsets or logical file offsets.
*/
bool od_physical;
/**
* XXX: We need to provide a persistently allocated string to hold
* unique object names for this policy, since in currently supported
* versions of Linux by Lustre, kmem_cache_create() just sets a pointer
* to the name string provided. kstrdup() is used in the version of
* kmeme_cache_create() in current Linux mainline, so we may be able to
* remove this in the future.
*/
char od_objname[NRS_ORR_OBJ_NAME_MAX];
};
/**
* Represents a backend-fs object or OST in the ORR and TRR policies
* respectively
*/
struct nrs_orr_object {
struct ptlrpc_nrs_resource oo_res;
struct rhash_head oo_rhead;
/**
* The round number against which requests are being scheduled for this
* object or OST
*/
__u64 oo_round;
/**
* The sequence number used for requests scheduled for this object or
* OST during the current round number.
*/
__u64 oo_sequence;
/**
* The key of the object or OST for which this structure
* instance is scheduling RPCs
*/
struct nrs_orr_key oo_key;
/**
* The reference count of this object. Once it hits zero free
* it from the hash table.
*/
refcount_t oo_ref;
/**
* Round Robin quantum; the maximum number of RPCs that are allowed to
* be scheduled for the object or OST in a single batch of each round.
*/
__u16 oo_quantum;
/**
* # of pending requests for this object or OST, on all existing rounds
*/
__u16 oo_active;
/**
* Needed to free this structure from the RCU.
*/
struct rcu_head oo_rcu_head;
};
/**
* ORR/TRR NRS request definition
*/
struct nrs_orr_req {
/**
* The offset range this request covers
*/
struct nrs_orr_req_range or_range;
/**
* Round number for this request; shared with all other requests in the
* same batch.
*/
__u64 or_round;
/**
* Sequence number for this request; shared with all other requests in
* the same batch.
*/
__u64 or_sequence;
/**
* For debugging purposes.
*/
struct nrs_orr_key or_key;
/**
* An ORR policy instance has filled in request information while
* enqueueing the request on the service partition's regular NRS head.
*/
unsigned int or_orr_set:1;
/**
* A TRR policy instance has filled in request information while
* enqueueing the request on the service partition's regular NRS head.
*/
unsigned int or_trr_set:1;
/**
* Request offset ranges have been filled in with logical offset
* values.
*/
unsigned int or_logical_set:1;
/**
* Request offset ranges have been filled in with physical offset
* values.
*/
unsigned int or_physical_set:1;
};
/** @} ORR/TRR */
#endif
