[PATCH v2 12/20] trace-cmd library: Extend the input handler with trace data decompression context

From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v2 12/20] trace-cmd library: Extend the input handler with trace data decompression context
Date: Tue, 14 Sep 2021 16:16:37 +0300	[thread overview]
Message-ID: <20210914131645.3966308-13-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210914131645.3966308-1-tz.stoyanov@gmail.com>

The CPU trace data is compressed in chunks, as chunk's size is multiple
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@gmail.com>
---
 lib/trace-cmd/trace-input.c | 59 ++++++++++++++++++++++++++++++-------
 1 file changed, 48 insertions(+), 11 deletions(-)

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index d4728c86..658855a5 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -54,6 +54,24 @@ 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 +90,7 @@ struct cpu_data {
 	int			page_cnt;
 	int			cpu;
 	int			pipe_fd;
+	struct cpu_zdata	compress;
 };
 
 struct cpu_file_data {
@@ -150,6 +169,8 @@ 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;
@@ -3302,6 +3323,7 @@ static int init_cpu_data(struct tracecmd_input *handle)
 		endian = KBUFFER_ENDIAN_LITTLE;
 
 	for (cpu = 0; cpu < handle->cpus; 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;
@@ -4043,6 +4065,7 @@ static inline void free_buffer(struct input_buffer_instance *buf)
  */
 void tracecmd_close(struct tracecmd_input *handle)
 {
+	struct zchunk_cache *cache;
 	struct file_section *del_sec;
 	int cpu;
 	int i;
@@ -4062,17 +4085,31 @@ void tracecmd_close(struct tracecmd_input *handle)
 		/* The tracecmd_peek_data may have cached a record */
 		free_next(handle, cpu);
 		free_page(handle, cpu);
-		if (handle->cpu_data && handle->cpu_data[cpu].kbuf) {
-			kbuffer_free(handle->cpu_data[cpu].kbuf);
-			if (handle->cpu_data[cpu].page_map)
-				free_page_map(handle->cpu_data[cpu].page_map);
-
-			if (handle->cpu_data[cpu].page_cnt)
-				tracecmd_warning("%d pages still allocated on cpu %d%s",
-						 handle->cpu_data[cpu].page_cnt, cpu,
-						 show_records(handle->cpu_data[cpu].pages,
-							      handle->cpu_data[cpu].nr_pages));
-			free(handle->cpu_data[cpu].pages);
+		if (handle->cpu_data) {
+			if (handle->cpu_data[cpu].kbuf) {
+				kbuffer_free(handle->cpu_data[cpu].kbuf);
+				if (handle->cpu_data[cpu].page_map)
+					free_page_map(handle->cpu_data[cpu].page_map);
+
+				if (handle->cpu_data[cpu].page_cnt)
+					tracecmd_warning("%d pages still allocated on cpu %d%s",
+							 handle->cpu_data[cpu].page_cnt, cpu,
+							 show_records(handle->cpu_data[cpu].pages,
+								      handle->cpu_data[cpu].nr_pages));
+				free(handle->cpu_data[cpu].pages);
+			}
+			if (handle->cpu_data[cpu].compress.fd >= 0) {
+				close(handle->cpu_data[cpu].compress.fd);
+				unlink(handle->cpu_data[cpu].compress.file);
+			}
+			while (!list_empty(&handle->cpu_data[cpu].compress.cache)) {
+				cache = container_of(handle->cpu_data[cpu].compress.cache.next,
+						     struct zchunk_cache, list);
+				list_del(&cache->list);
+				free(cache->map);
+				free(cache);
+			}
+			free(handle->cpu_data[cpu].compress.chunks);
 		}
 	}
 
-- 
2.31.1

