On Thu, Aug 19, 2021 at 10:18 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Thu, 29 Jul 2021 08:09:23 +0300
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
>
> > The CPU tarce data is compressed in chunks, as chunk's size is multiple
>
> typos.
>
> > trace pages. The input handler is extended with the necessary
> > structures, to control the data decompression. There are two approaches
> > for data decompression, both are supported and can be used in different
> > use cases:
> > - in-memory decompression, page by page.
> > - using a temporary file
> >
> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> > ---
> > lib/trace-cmd/trace-input.c | 66 ++++++++++++++++++++++++++++++-------
> > 1 file changed, 54 insertions(+), 12 deletions(-)
> >
> > diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
> > index 520d611f..6fb63c0f 100644
> > --- a/lib/trace-cmd/trace-input.c
> > +++ b/lib/trace-cmd/trace-input.c
> > @@ -29,6 +29,9 @@
> >
> > #define COMMIT_MASK ((1 << 27) - 1)
> >
> > +/* force uncompressing in memory */
> > +#define INMEMORY_DECOMPRESS
>
> I wonder if we should just make this a variable in the handle, and
> default it to in memory. Then it will be easy to change it from the
> command line if we want to.
There is "read_zpage", introduced in this patch. It controls whether
to use in memory decompression. The define is used to set the default
value of read_zpage, when the handler is allocated.
>
> -- Steve
>
> > +
> > /* for debugging read instead of mmap */
> > static int force_read = 0;
> >
> > @@ -54,6 +57,24 @@ struct page {
> > #endif
> > };
> >
> > +struct zchunk_cache {
> > + struct list_head list;
> > + struct tracecmd_compress_chunk *chunk;
> > + void *map;
> > + int ref;
> > +};
> > +
> > +struct cpu_zdata {
> > + /* uncompressed cpu data */
> > + int fd;
> > + char file[26]; /*
> > strlen(COMPR_TEMP_FILE) */
> > + unsigned int count;
> > + unsigned int last_chunk;
> > + struct list_head cache;
> > + struct tracecmd_compress_chunk *chunks;
> > +};
> > +
> > +#define COMPR_TEMP_FILE "/tmp/trace_cpu_dataXXXXXX"
> > struct cpu_data {
> > /* the first two never change */
> > unsigned long long file_offset;
> > @@ -72,6 +93,7 @@ struct cpu_data {
> > int page_cnt;
> > int cpu;
> > int pipe_fd;
> > + struct cpu_zdata compress;
> > };
> >
> > struct cpu_file_data {
> > @@ -150,6 +172,8 @@ struct tracecmd_input {
> > bool use_trace_clock;
> > bool read_page;
> > bool use_pipe;
> > + bool read_zpage; /* uncompress pages
> > in memory, do not use tmp files */
> > + bool cpu_compressed;
> > int file_version;
> > struct cpu_data *cpu_data;
> > long long ts_offset;
> > @@ -3284,7 +3308,7 @@ static int read_cpu_data(struct tracecmd_input
> > *handle) unsigned long long offset;
> >
> > handle->cpu_data[cpu].cpu = cpu;
> > -
> > + handle->cpu_data[cpu].compress.fd = -1;
> > handle->cpu_data[cpu].kbuf =
> > kbuffer_alloc(long_size, endian); if (!handle->cpu_data[cpu].kbuf)
> > goto out_free;
> > @@ -3701,6 +3725,9 @@ struct tracecmd_input *tracecmd_alloc_fd(int
> > fd, int flags) /* By default, use usecs, unless told otherwise */
> > handle->flags |= TRACECMD_FL_IN_USECS;
> >
> > +#ifdef INMEMORY_DECOMPRESS
> > + handle->read_zpage = 1;
> > +#endif
> > if (do_read_check(handle, buf, 3))
> > goto failed_read;
> >
> > @@ -3915,6 +3942,7 @@ void tracecmd_ref(struct tracecmd_input *handle)
> > */
> > void tracecmd_close(struct tracecmd_input *handle)
> > {
> > + struct zchunk_cache *cache;
> > struct file_section *del_sec;
> > int i;
> >
> > @@ -3933,17 +3961,31 @@ void tracecmd_close(struct tracecmd_input
> > *handle) /* The tracecmd_peek_data may have cached a record */
> > free_next(handle, i);
> > free_page(handle, i);
> > - if (handle->cpu_data && handle->cpu_data[i].kbuf) {
> > - kbuffer_free(handle->cpu_data[i].kbuf);
> > - if (handle->cpu_data[i].page_map)
> > -
> > free_page_map(handle->cpu_data[i].page_map); -
> > - if (handle->cpu_data[i].page_cnt)
> > - tracecmd_warning("%d pages still
> > allocated on cpu %d%s",
> > -
> > handle->cpu_data[i].page_cnt, i,
> > -
> > show_records(handle->cpu_data[i].pages,
> > -
> > handle->cpu_data[i].nr_pages));
> > - free(handle->cpu_data[i].pages);
> > + if (handle->cpu_data) {
> > + if (handle->cpu_data[i].kbuf) {
> > +
> > kbuffer_free(handle->cpu_data[i].kbuf);
> > + if (handle->cpu_data[i].page_map)
> > +
> > free_page_map(handle->cpu_data[i].page_map); +
> > + if (handle->cpu_data[i].page_cnt)
> > + tracecmd_warning("%d pages
> > still allocated on cpu %d%s",
> > +
> > handle->cpu_data[i].page_cnt, i,
> > +
> > show_records(handle->cpu_data[i].pages,
> > +
> > handle->cpu_data[i].nr_pages));
> > + free(handle->cpu_data[i].pages);
> > + }
> > + if (handle->cpu_data[i].compress.fd >= 0) {
> > +
> > close(handle->cpu_data[i].compress.fd);
> > +
> > unlink(handle->cpu_data[i].compress.file);
> > + }
> > + while
> > (!list_empty(&handle->cpu_data[i].compress.cache)) {
> > + cache =
> > container_of(handle->cpu_data[i].compress.cache.next,
> > + struct
> > zchunk_cache, list);
> > + list_del(&cache->list);
> > + free(cache->map);
> > + free(cache);
> > + }
> > + free(handle->cpu_data[i].compress.chunks);
> > }
> > }
> >
>
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
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