From: Su, Friendy Date: Wed, 22 Jan 2020 15:31:25 +0000 (-0700) Subject: engines: add engine for file stat X-Git-Tag: fio-3.18~9 X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=73ccd14e52d1379fb0848811894125a5a8cd954a engines: add engine for file stat This engine is to measure performance of accessing file's meta data. This is for the actual access pattern which does not do real IO, but just look up the file and get file's attribute. Signed-off-by: Jens Axboe --- diff --git a/HOWTO b/HOWTO index 41d32c04..74318954 100644 --- a/HOWTO +++ b/HOWTO @@ -1996,6 +1996,11 @@ I/O engine set `filesize` so that all the accounting still occurs, but no actual I/O will be done other than creating the file. + **filestat** + Simply do stat() and do no I/O to the file. You need to set 'filesize' + and 'nrfiles', so that files will be created. + This engine is to measure file lookup and meta data access. + **libpmem** Read and write using mmap I/O to a file on a filesystem mounted with DAX on a persistent memory device through the PMDK diff --git a/Makefile b/Makefile index 3c5e0f5b..027b62bc 100644 --- a/Makefile +++ b/Makefile @@ -45,7 +45,7 @@ SOURCE := $(sort $(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/crc/*.c)) \ pshared.c options.c \ smalloc.c filehash.c profile.c debug.c engines/cpu.c \ engines/mmap.c engines/sync.c engines/null.c engines/net.c \ - engines/ftruncate.c engines/filecreate.c \ + engines/ftruncate.c engines/filecreate.c engines/filestat.c \ server.c client.c iolog.c backend.c libfio.c flow.c cconv.c \ gettime-thread.c helpers.c json.c idletime.c td_error.c \ profiles/tiobench.c profiles/act.c io_u_queue.c filelock.c \ diff --git a/engines/filestat.c b/engines/filestat.c new file mode 100644 index 00000000..9a394fe2 --- /dev/null +++ b/engines/filestat.c @@ -0,0 +1,116 @@ +/* + * filestat engine + * + * IO engine that doesn't do any IO, just stat files and tracks the latency + * of the file stat. + */ +#include +#include +#include +#include +#include +#include +#include "../fio.h" + +struct fc_data { + enum fio_ddir stat_ddir; +}; + +static int stat_file(struct thread_data *td, struct fio_file *f) +{ + struct timespec start; + int do_lat = !td->o.disable_lat; + struct stat statbuf; + int ret; + + dprint(FD_FILE, "fd stat %s\n", f->file_name); + + if (f->filetype != FIO_TYPE_FILE) { + log_err("fio: only files are supported\n"); + return 1; + } + if (!strcmp(f->file_name, "-")) { + log_err("fio: can't read/write to stdin/out\n"); + return 1; + } + + if (do_lat) + fio_gettime(&start, NULL); + + ret = stat(f->file_name, &statbuf); + + if (ret == -1) { + char buf[FIO_VERROR_SIZE]; + int e = errno; + + snprintf(buf, sizeof(buf), "stat(%s)", f->file_name); + td_verror(td, e, buf); + return 1; + } + + if (do_lat) { + struct fc_data *data = td->io_ops_data; + uint64_t nsec; + + nsec = ntime_since_now(&start); + add_clat_sample(td, data->stat_ddir, nsec, 0, 0); + } + + return 0; +} + +static enum fio_q_status queue_io(struct thread_data *td, struct io_u fio_unused *io_u) +{ + return FIO_Q_COMPLETED; +} + +static int init(struct thread_data *td) +{ + struct fc_data *data; + + data = calloc(1, sizeof(*data)); + + if (td_read(td)) + data->stat_ddir = DDIR_READ; + else if (td_write(td)) + data->stat_ddir = DDIR_WRITE; + + td->io_ops_data = data; + return 0; +} + +static void cleanup(struct thread_data *td) +{ + struct fc_data *data = td->io_ops_data; + + free(data); +} + +static int stat_invalidate(struct thread_data *td, struct fio_file *f) +{ + /* do nothing because file not opened */ + return 0; +} + +static struct ioengine_ops ioengine = { + .name = "filestat", + .version = FIO_IOOPS_VERSION, + .init = init, + .cleanup = cleanup, + .queue = queue_io, + .invalidate = stat_invalidate, + .get_file_size = generic_get_file_size, + .open_file = stat_file, + .flags = FIO_SYNCIO | FIO_FAKEIO | + FIO_NOSTATS | FIO_NOFILEHASH, +}; + +static void fio_init fio_filestat_register(void) +{ + register_ioengine(&ioengine); +} + +static void fio_exit fio_filestat_unregister(void) +{ + unregister_ioengine(&ioengine); +} diff --git a/examples/filestat-ioengine.fio b/examples/filestat-ioengine.fio new file mode 100644 index 00000000..932fced8 --- /dev/null +++ b/examples/filestat-ioengine.fio @@ -0,0 +1,19 @@ +# Example filestat job + +# 'filestat' engine only do 'stat(filename)', file will not be open(). +# 'filesize' must be set, then files will be created at setup stage. + +[global] +ioengine=filestat +numjobs=1 +filesize=4k +nrfiles=200 +thread + +[t0] +[t1] +[t2] +[t3] +[t4] +[t5] + diff --git a/fio.1 b/fio.1 index cf5dd853..6283fc1d 100644 --- a/fio.1 +++ b/fio.1 @@ -1760,6 +1760,11 @@ Simply create the files and do no I/O to them. You still need to set \fBfilesize\fR so that all the accounting still occurs, but no actual I/O will be done other than creating the file. .TP +.B filestat +Simply do stat() and do no I/O to the file. You need to set 'filesize' +and 'nrfiles', so that files will be created. +This engine is to measure file lookup and meta data access. +.TP .B libpmem Read and write using mmap I/O to a file on a filesystem mounted with DAX on a persistent memory device through the PMDK