On 19.11.20 г. 4:00 ч., Steven Rostedt wrote:
On Wed, 18 Nov 2020 16:49:57 +0200 "Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> wrote:The C API provides loading of the trace data in two different forms. The firs one is an array of kshark_entries and is being used by the"first one"KernelShark GUI. The second is a matrix-like structure that has all the fields of the kshark_entry stored in separate arrays, forming the columns of the matrix. The second form of the data is used by trace-cruncher. In this patch we add methods for merging of several data streams into a single data set. Both kshark_entries and matrix forms of the data are supported. This patch includes a simple example that demonstrate how to open a file that contains multiple buffers. Each buffers is loaded into a separate Data stream and those streams are merged together. Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx> --- examples/CMakeLists.txt | 4 + examples/multibufferload.c | 60 +++++++++ src/libkshark.c | 255 +++++++++++++++++++++++++++++++++++++ src/libkshark.h | 47 +++++++ 4 files changed, 366 insertions(+) create mode 100644 examples/multibufferload.c diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt index 8d40e42c..831eee24 100644 --- a/examples/CMakeLists.txt +++ b/examples/CMakeLists.txt @@ -8,6 +8,10 @@ message(STATUS "datafilter") add_executable(dfilter datafilter.c) target_link_libraries(dfilter kshark)+message(STATUS "multibufferload")+add_executable(mbload multibufferload.c) +target_link_libraries(mbload kshark) + # message(STATUS "datahisto") # add_executable(dhisto datahisto.c) # target_link_libraries(dhisto kshark) diff --git a/examples/multibufferload.c b/examples/multibufferload.c new file mode 100644 index 00000000..70b2733a --- /dev/null +++ b/examples/multibufferload.c @@ -0,0 +1,60 @@ +#include <stdio.h> +#include <stdlib.h> + +#include "libkshark.h" +#include "libkshark-tepdata.h" + +const char *default_file = "trace.dat"; + +void put_entry(struct kshark_entry *e) +{ + char *entry_str = kshark_dump_entry(e); + puts(entry_str); + free(entry_str); +} + +int main(int argc, char **argv) +{ + struct kshark_context *kshark_ctx; + struct kshark_entry **data = NULL; + ssize_t r, n_rows; + int sd; + + /* Create a new kshark session. */ + kshark_ctx = NULL; + if (!kshark_instance(&kshark_ctx)) + return 1; + + /* Open a trace data file produced by trace-cmd. */ + if (argc > 1) + sd = kshark_open(kshark_ctx, argv[1]); + else + sd = kshark_open(kshark_ctx, default_file);I'm confused. It doesn't look like this merges more than one stream.
Hi Steven, Here it only opens the "top" buffer in the file.
-- Steve+ + if (sd < 0) { + kshark_free(kshark_ctx); + return 1; + } + + /* Initialize data streams for all buffers in this file. */ + kshark_tep_init_all_buffers(kshark_ctx, sd);
And here is the place where it opens in separate streams the other buffers that are in the same file.
+ + /* Load all buffers. */ + n_rows = kshark_load_all_entries(kshark_ctx, &data); +
Here it loads and merges the entries from all buffers. Thanks! Yordan
+ /* Print to the screen the first 20 entries. */ + for (r = 0; r < 20; ++r) + put_entry(data[r]); + + /* Free the memory. */ + for (r = 0; r < n_rows; ++r) + free(data[r]); + free(data); + + kshark_close_all(kshark_ctx); + + /* Close the session. */ + kshark_free(kshark_ctx); + + return 0; +}
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