Commit 3a0f6244 authored by Jim Harris's avatar Jim Harris Committed by Tomasz Zawadzki
Browse files

nvmf: add USDT probes for subsystem state changes 



Also add scripts/bpf/nvmf.bt to enable and log these
probes.

This patch also adds a script that can generate
a bpftrace script snippet with string maps for
needed enumerations (currently nvmf_tgt_state and
spdk_nvmf_subsystem_state).  This allows us to
dynamically generate this from the source code, and
can be extended for other enums we may want to
add in the future.

Thanks to Michal Berger for converting my original
gen_enums.py script into gen_enums.sh!

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Signed-off-by: default avatarMichal Berger <michalx.berger@intel.com>
Change-Id: Iff34a6218aef40055ac14932eea5fc00e1c8bcf5
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/7194


Community-CI: Mellanox Build Bot
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
parent 109106d8

lib/nvmf/subsystem.c

+14 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include "spdk/bdev_module.h"

#include "spdk/log.h"

#include "spdk_internal/utf.h"

#include "spdk_internal/usdt.h"



#define MODEL_NUMBER_DEFAULT "SPDK bdev Controller"

#define NVMF_SUBSYSTEM_DEFAULT_NAMESPACES 32
@@ -508,6 +509,9 @@ subsystem_state_change_done(struct spdk_io_channel_iter *i, int status) 
	struct subsystem_state_change_ctx *ctx = spdk_io_channel_iter_get_ctx(i);

	enum spdk_nvmf_subsystem_state intermediate_state;



	SPDK_DTRACE_PROBE4(nvmf_subsystem_change_state_done, ctx->subsystem->subnqn,

			   ctx->requested_state, ctx->original_state, status);



	if (status == 0) {

		status = nvmf_subsystem_set_state(ctx->subsystem, ctx->requested_state);

		if (status) {
@@ -543,6 +547,12 @@ static void 
subsystem_state_change_continue(void *ctx, int status)

{

	struct spdk_io_channel_iter *i = ctx;

	struct subsystem_state_change_ctx *_ctx __attribute__((unused));



	_ctx = spdk_io_channel_iter_get_ctx(i);

	SPDK_DTRACE_PROBE3(nvmf_pg_change_state_done, _ctx->subsystem->subnqn,

			   _ctx->requested_state, spdk_thread_get_id(spdk_get_thread()));



	spdk_for_each_channel_continue(i, status);

}
@@ -557,6 +567,8 @@ subsystem_state_change_on_pg(struct spdk_io_channel_iter *i) 
	ch = spdk_io_channel_iter_get_channel(i);

	group = spdk_io_channel_get_ctx(ch);



	SPDK_DTRACE_PROBE3(nvmf_pg_change_state, ctx->subsystem->subnqn,

			   ctx->requested_state, spdk_thread_get_id(spdk_get_thread()));

	switch (ctx->requested_state) {

	case SPDK_NVMF_SUBSYSTEM_INACTIVE:

		nvmf_poll_group_remove_subsystem(group, ctx->subsystem, subsystem_state_change_continue, i);
@@ -593,6 +605,8 @@ nvmf_subsystem_state_change(struct spdk_nvmf_subsystem *subsystem, 
		return -EBUSY;

	}



	SPDK_DTRACE_PROBE3(nvmf_subsystem_change_state, subsystem->subnqn,

			   requested_state, subsystem->state);

	/* If we are already in the requested state, just call the callback immediately. */

	if (subsystem->state == requested_state) {

		subsystem->changing_state = false;

module/event/subsystems/nvmf/nvmf_tgt.c

+2 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include "spdk/log.h"

#include "spdk/nvme.h"

#include "spdk/nvmf_cmd.h"

#include "spdk_internal/usdt.h"



enum nvmf_tgt_state {

	NVMF_TGT_INIT_NONE = 0,
@@ -378,6 +379,7 @@ nvmf_tgt_advance_state(void) 
	int ret;



	do {

		SPDK_DTRACE_PROBE1(nvmf_tgt_state, g_tgt_state);

		prev_state = g_tgt_state;



		switch (g_tgt_state) {

scripts/bpf/gen_enums.sh

0 → 100755
+52 −0
Original line number Diff line number Diff line 
#!/usr/bin/env bash

set -e



rootdir=$(git rev-parse --show-toplevel)



_print_enums() {

	local enum_type=$1 enum_string=$2 enum_prefix=$3 enum output



	output=$(< "$rootdir/$(git -C "$rootdir" grep -l "$enum_string" -- lib module)")



	# Isolate the enum block

	output=${output#*$enum_string$'\n'} output=${output%%$'\n'\};*}

	# Fold it onto an array

	IFS="," read -ra output <<< "${output//[[:space:]]/}"

	# Drop the assignments

	output=("${output[@]/=*/}")



	for enum in "${!output[@]}"; do

		if [[ ${output[enum]} != "$enum_prefix"* ]]; then

			printf 'enum name %s does not start with expected prefix %s\n' "${output[enum]}" "$enum_prefix"

			return 1

		fi >&2

		printf '  @%s[%d] = "%s";\n' "$enum_type" "$enum" "${output[enum]#$enum_prefix}"

	done

}



print_enums() {

	for state in "${!state_enums[@]}"; do

		_print_enums "$state" "${state_enums["$state"]}" "${state_prefix["$state"]}"

	done

}



print_clear() { printf '  clear(@%s);\n' "${!state_enums[@]}"; }



declare -A state_enums=() state_prefix=()



state_enums["target"]="enum nvmf_tgt_state {"

state_enums["subsystem"]="enum spdk_nvmf_subsystem_state {"

state_prefix["target"]=NVMF_TGT_

state_prefix["subsystem"]=SPDK_NVMF_SUBSYSTEM_



enums=$(print_enums)

clear=$(print_clear)



cat <<- ENUM

	BEGIN {

		$enums

	}

	END {

		$clear

	}

ENUM

scripts/bpf/nvmf.bt

0 → 100644
+29 −0
Original line number Diff line number Diff line 
usdt:__EXE__:nvmf_tgt_state {

	printf("%d.%06d: nvmf_tgt reached state %s\n",

	       elapsed / (uint64)(1000 * 1000), elapsed % (uint64)(1000 * 1000),

	       @target[arg0]);

}



usdt:__EXE__:nvmf_subsystem_change_state {

	printf("%d.%06d: %s change state from %s to %s start\n",

	       elapsed / (uint64)(1000 * 1000), elapsed % (uint64)(1000 * 1000),

	       str(arg0), @subsystem[arg2], @subsystem[arg1]);

}



usdt:__EXE__:nvmf_subsystem_change_state_done {

	printf("%d.%06d: %s change state from %s to %s %s\n",

	       elapsed / (uint64)(1000 * 1000), elapsed % (uint64)(1000 * 1000),

	       str(arg0), @subsystem[arg2], @subsystem[arg1], arg3 ? "failed" : "done");

}



usdt:__EXE__:nvmf_pg_change_state {

	printf("%d.%06d: %s on thread %d state to %s start\n",

	       elapsed / (uint64)(1000 * 1000), elapsed % (uint64)(1000 * 1000),

	       str(arg0), arg2, @subsystem[arg1]);

}



usdt:__EXE__:nvmf_pg_change_state_done {

	printf("%d.%06d: %s on thread %d state to %s done\n",

	       elapsed / (uint64)(1000 * 1000), elapsed % (uint64)(1000 * 1000),

	       str(arg0), arg2, @subsystem[arg1]);

}

scripts/bpftrace.sh

+7 −1
Original line number Diff line number Diff line 
#!/usr/bin/env bash

set -e



if [ $# -lt 2 ]; then

	echo "usage: $0 <pid> <script>"

	exit 1

fi

SCRIPTS_DIR=$(readlink -f $(dirname $0))

BIN_PATH=$(readlink -f /proc/$1/exe)

BPF_SCRIPT=$(sed "s#__EXE__#${BIN_PATH}#g" "${@:2}" | sed "s#__PID__#${1}#g")

BPF_SCRIPT=$($SCRIPTS_DIR/bpf/gen_enums.sh)

BPF_SCRIPT+=$(sed "s#__EXE__#${BIN_PATH}#g" "${@:2}" | sed "s#__PID__#${1}#g")

if [ -n "$ECHO_SCRIPT" ]; then

	echo "$BPF_SCRIPT"

fi

bpftrace -p $1 -e "$BPF_SCRIPT"