Commit 3fb4a66d authored by Seth Howell's avatar Seth Howell Committed by Darek Stojaczyk
Browse files

bdev: Create a new delay vbdev module 



This module simply sits on another virtual bdev
and adds a simulated average and p99 latency to that drive.

Change-Id: Ie9fc91e27585fd0636cb7dc845cb41744bf24625
Signed-off-by: default avatarSeth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/453594


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
parent ce31ec39

CHANGELOG.md

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@@ -24,6 +24,16 @@ The format of the data returned by the get_bdevs_iostat RPC has changed to 
make it easier to parse.  It now returns an object with a "ticks" object

and "bdevs" array with the per-bdev statistics.



A new bdev module `delay` has been added which simulates a drive latency when placed

on top of a Null bdev. This module is intended only for testing and can be created using

the new RPC `bdev_delay_create`. That RPC takes the name of the underlying bdev as well

as average and p99 latency arguments for both read and write operations. Average latency is

defined as a value close to what you would expect a perf tool such as FIO to report back as

the mean latency of all I/O submitted to the drive. p99 latency is defined as the value one

would expect the drive to see the slowest 1% of I/O report. For underlying drives with already

significant latency, the latency values provided to the drive will be additive. This should be

taken into account if trying to achieve an artificial latency on top of an nvme drive or aio device.



### nvme



Added spdk_nvme_ctrlr_get_transport_id() to get the transport ID from a

doc/jsonrpc.md

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@@ -1672,6 +1672,92 @@ Example response: 
}

~~~



## bdev_delay_create {#rpc_bdev_delay_create}



Create delay bdev. This bdev type redirects all IO to it's base bdev and inserts a delay on the completion

path to create an artificial drive latency.



### Parameters



Name                    | Optional | Type        | Description

----------------------- | -------- | ----------- | -----------

name                    | Required | string      | Bdev name

base_bdev_name          | Required | string      | Base bdev name

avg_read_latency        | Required | number      | average read latency (us)

p99_read_latency        | Required | number      | p99 read latency (us)

avg_write_latency       | Required | number      | average write latency (us)

p99_write_latency       | Required | number      | p99 write latency (us)



### Result



Name of newly created bdev.



### Example



Example request:



~~~

{

  "params": {

    "base_bdev_name": "Null0",

    "name": "Delay0",

    "avg_read_latency": "15",

    "p99_read_latency": "50",

    "avg_write_latency": "40",

    "p99_write_latency": "110",

  },

  "jsonrpc": "2.0",

  "method": "bdev_delay_create",

  "id": 1

}

~~~



Example response:



~~~

{

  "jsonrpc": "2.0",

  "id": 1,

  "result": "Delay0"

}

~~~



## bdev_delay_delete {#rpc_bdev_delay_delete}



Delete delay bdev.



### Parameters



Name                    | Optional | Type        | Description

----------------------- | -------- | ----------- | -----------

name                    | Required | string      | Bdev name



### Example



Example request:



~~~

{

  "params": {

    "name": "Delay0"

  },

  "jsonrpc": "2.0",

  "method": "bdev_delay_delete",

  "id": 1

}



~~~



Example response:



~~~

{

  "jsonrpc": "2.0",

  "id": 1,

  "result": true

}

~~~



## construct_error_bdev {#rpc_construct_error_bdev}



Construct error bdev.

lib/bdev/Makefile

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@@ -42,7 +42,7 @@ C_SRCS = bdev.c part.c scsi_nvme.c 
C_SRCS-$(CONFIG_VTUNE) += vtune.c

LIBNAME = bdev



DIRS-y += error gpt lvol malloc null nvme passthru raid rpc split

DIRS-y += delay error gpt lvol malloc null nvme passthru raid rpc split



ifeq ($(CONFIG_CRYPTO),y)

DIRS-y += crypto

lib/bdev/delay/Makefile

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#

#  BSD LICENSE

#

#  Copyright (c) Intel Corporation.

#  All rights reserved.

#

#  Redistribution and use in source and binary forms, with or without

#  modification, are permitted provided that the following conditions

#  are met:

#

#    * Redistributions of source code must retain the above copyright

#      notice, this list of conditions and the following disclaimer.

#    * Redistributions in binary form must reproduce the above copyright

#      notice, this list of conditions and the following disclaimer in

#      the documentation and/or other materials provided with the

#      distribution.

#    * Neither the name of Intel Corporation nor the names of its

#      contributors may be used to endorse or promote products derived

#      from this software without specific prior written permission.

#

#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

#  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

#  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

#  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

#  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

#  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#



SPDK_ROOT_DIR := $(abspath $(CURDIR)/../../..)

include $(SPDK_ROOT_DIR)/mk/spdk.common.mk



CFLAGS += -I$(SPDK_ROOT_DIR)/lib/bdev/



C_SRCS = vbdev_delay.c vbdev_delay_rpc.c

LIBNAME = bdev_delay



include $(SPDK_ROOT_DIR)/mk/spdk.lib.mk

lib/bdev/delay/vbdev_delay.c

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