Messages in this thread | | | Date | Thu, 29 Apr 2021 11:31:54 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 04/12] perf inject: Add facility to do in place update |
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Em Thu, Apr 29, 2021 at 03:58:46PM +0300, Adrian Hunter escreveu: > When there is a need to modify only timestamps, it is much simpler and > quicker to do it to the existing file rather than re-write all the > contents. > > In preparation for that, add the ability to modify the input file in place. > In practice that just means making the file descriptor and mmaps writable.
Clever, and you took care of checking that the constraints are met, and I see this paves the way for the actual 'perf inject' option that uses this new 'perf inject' mode.
- Arnaldo
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/builtin-inject.c | 30 ++++++++++++++++++++++++++---- > tools/perf/util/data.c | 3 ++- > tools/perf/util/data.h | 1 + > tools/perf/util/header.c | 5 +++++ > tools/perf/util/session.c | 6 +++++- > 5 files changed, 39 insertions(+), 6 deletions(-) > > diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c > index ddccc0eb7390..ddfdeb85c586 100644 > --- a/tools/perf/builtin-inject.c > +++ b/tools/perf/builtin-inject.c > @@ -43,6 +43,8 @@ struct perf_inject { > bool have_auxtrace; > bool strip; > bool jit_mode; > + bool in_place_update; > + bool in_place_update_dry_run; > const char *input_name; > struct perf_data output; > u64 bytes_written; > @@ -701,7 +703,7 @@ static int __cmd_inject(struct perf_inject *inject) > int ret = -EINVAL; > struct perf_session *session = inject->session; > struct perf_data *data_out = &inject->output; > - int fd = perf_data__fd(data_out); > + int fd = inject->in_place_update ? -1 : perf_data__fd(data_out); > u64 output_data_offset; > > signal(SIGINT, sig_handler); > @@ -759,14 +761,14 @@ static int __cmd_inject(struct perf_inject *inject) > if (!inject->itrace_synth_opts.set) > auxtrace_index__free(&session->auxtrace_index); > > - if (!data_out->is_pipe) > + if (!data_out->is_pipe && !inject->in_place_update) > lseek(fd, output_data_offset, SEEK_SET); > > ret = perf_session__process_events(session); > if (ret) > return ret; > > - if (!data_out->is_pipe) { > + if (!data_out->is_pipe && !inject->in_place_update) { > if (inject->build_ids) > perf_header__set_feat(&session->header, > HEADER_BUILD_ID); > @@ -900,7 +902,27 @@ int cmd_inject(int argc, const char **argv) > return -1; > } > > - if (perf_data__open(&inject.output)) { > + if (inject.in_place_update) { > + if (!strcmp(inject.input_name, "-")) { > + pr_err("Input file name required for in-place updating\n"); > + return -1; > + } > + if (strcmp(inject.output.path, "-")) { > + pr_err("Output file name must not be specified for in-place updating\n"); > + return -1; > + } > + if (!data.force && !inject.in_place_update_dry_run) { > + char reply[10]; > + > + printf("The input file will be updated in place. OK? (y/n) "); > + if (!fgets(reply, sizeof(reply), stdin) || strcmp(reply, "y\n")) { > + pr_err("Aborted\n"); > + return -1; > + } > + } > + if (!inject.in_place_update_dry_run) > + data.in_place_update = true; > + } else if (perf_data__open(&inject.output)) { > perror("failed to create output file"); > return -1; > } > diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c > index f29af4fc3d09..209fe63d4e49 100644 > --- a/tools/perf/util/data.c > +++ b/tools/perf/util/data.c > @@ -239,11 +239,12 @@ static bool is_dir(struct perf_data *data) > > static int open_file_read(struct perf_data *data) > { > + int flags = data->in_place_update ? O_RDWR : O_RDONLY; > struct stat st; > int fd; > char sbuf[STRERR_BUFSIZE]; > > - fd = open(data->file.path, O_RDONLY); > + fd = open(data->file.path, flags); > if (fd < 0) { > int err = errno; > > diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h > index 62a3e66fbee8..c9de82af5584 100644 > --- a/tools/perf/util/data.h > +++ b/tools/perf/util/data.h > @@ -31,6 +31,7 @@ struct perf_data { > bool is_dir; > bool force; > bool use_stdio; > + bool in_place_update; > enum perf_data_mode mode; > > struct { > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c > index aa1e42518d37..02b13c7a23be 100644 > --- a/tools/perf/util/header.c > +++ b/tools/perf/util/header.c > @@ -3814,6 +3814,11 @@ int perf_session__read_header(struct perf_session *session) > if (perf_file_header__read(&f_header, header, fd) < 0) > return -EINVAL; > > + if (header->needs_swap && data->in_place_update) { > + pr_err("In-place update not supported when byte-swapping is required\n"); > + return -EINVAL; > + } > + > /* > * Sanity check that perf.data was written cleanly; data size is > * initialized to 0 and updated only if the on_exit function is run. > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index eba3769be3f1..edd068ea8a6c 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -2131,6 +2131,7 @@ struct reader { > u64 data_size; > u64 data_offset; > reader_cb_t process; > + bool in_place_update; > }; > > static int > @@ -2164,7 +2165,9 @@ reader__process_events(struct reader *rd, struct perf_session *session, > mmap_prot = PROT_READ; > mmap_flags = MAP_SHARED; > > - if (session->header.needs_swap) { > + if (rd->in_place_update) { > + mmap_prot |= PROT_WRITE; > + } else if (session->header.needs_swap) { > mmap_prot |= PROT_WRITE; > mmap_flags = MAP_PRIVATE; > } > @@ -2250,6 +2253,7 @@ static int __perf_session__process_events(struct perf_session *session) > .data_size = session->header.data_size, > .data_offset = session->header.data_offset, > .process = process_simple, > + .in_place_update = session->data->in_place_update, > }; > struct ordered_events *oe = &session->ordered_events; > struct perf_tool *tool = session->tool; > -- > 2.17.1 >
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- Arnaldo
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