From: Marcelo Tosatti <mtosatti@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Junyao Zhao <junzhao@redhat.com>, Nini Gu <ngu@redhat.com>,
linux-trace-devel@vger.kernel.org
Subject: [PATCH] trace-cmd: support -m parameter for virt instances
Date: Thu, 7 Mar 2024 09:15:28 -0300 [thread overview]
Message-ID: <Zemv4OUx1WexdrlB@tpad> (raw)
Take into consideration the value passed in with "-m",
the max size in kilobytes that a per cpu buffer should be,
when reading trace data from guests.
This allows one to prevent running out of diskspace on long runs.
Reported-by: Junyao Zhao <junzhao@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index f2cf8dc8..2d14ed7a 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -370,7 +370,7 @@ enum {
void tracecmd_free_recorder(struct tracecmd_recorder *recorder);
struct tracecmd_recorder *tracecmd_create_recorder(const char *file, int cpu, unsigned flags);
struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu, unsigned flags);
-struct tracecmd_recorder *tracecmd_create_recorder_virt(const char *file, int cpu, unsigned flags, int trace_fd);
+struct tracecmd_recorder *tracecmd_create_recorder_virt(const char *file, int cpu, unsigned flags, int trace_fd, int maxkb);
struct tracecmd_recorder *tracecmd_create_recorder_maxkb(const char *file, int cpu, unsigned flags, int maxkb);
struct tracecmd_recorder *tracecmd_create_buffer_recorder_fd(int fd, int cpu, unsigned flags, struct tracefs_instance *instance);
struct tracecmd_recorder *tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags, struct tracefs_instance *instance);
diff --git a/lib/trace-cmd/trace-recorder.c b/lib/trace-cmd/trace-recorder.c
index 0633edf5..44f245d5 100644
--- a/lib/trace-cmd/trace-recorder.c
+++ b/lib/trace-cmd/trace-recorder.c
@@ -175,19 +175,46 @@ tracecmd_create_buffer_recorder_fd(int fd, int cpu, unsigned flags, struct trace
static struct tracecmd_recorder *
__tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags,
- struct tracefs_instance *instance, int tfd)
+ struct tracefs_instance *instance, int tfd, int maxkb)
{
struct tracecmd_recorder *recorder;
- int fd;
+ int fd, fd2 = -1;
+ char *file2;
- fd = open(file, O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+ fd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
if (fd < 0)
return NULL;
- recorder = create_buffer_recorder_fd2(fd, -1, cpu, flags, instance, 0, tfd);
+ if (maxkb) {
+ int len = strlen(file);
+
+ file2 = malloc(len + 3);
+ if (!file2)
+ return NULL;
+
+ sprintf(file2, "%s.1", file);
+
+ fd2 = open(file2, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+ if (fd2 < 0) {
+ close(fd);
+ unlink(file);
+ free(file2);
+ return NULL;
+ }
+ }
+
+ recorder = create_buffer_recorder_fd2(fd, fd2, cpu, flags, instance, maxkb, tfd);
if (!recorder) {
close(fd);
unlink(file);
+ if (fd2 != -1)
+ close(fd2);
+ }
+
+ if (fd2 != -1) {
+ /* Unlink file2, we need to add everything to file at the end */
+ unlink(file2);
+ free(file2);
}
return recorder;
@@ -242,7 +269,7 @@ struct tracecmd_recorder *
tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags,
struct tracefs_instance *instance)
{
- return __tracecmd_create_buffer_recorder(file, cpu, flags, instance, -1);
+ return __tracecmd_create_buffer_recorder(file, cpu, flags, instance, -1, 0);
}
/**
@@ -255,9 +282,9 @@ tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags,
*/
struct tracecmd_recorder *
tracecmd_create_recorder_virt(const char *file, int cpu, unsigned flags,
- int trace_fd)
+ int trace_fd, int maxkb)
{
- return __tracecmd_create_buffer_recorder(file, cpu, flags, NULL, trace_fd);
+ return __tracecmd_create_buffer_recorder(file, cpu, flags, NULL, trace_fd, maxkb);
}
struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu, unsigned flags)
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 91cc90d4..69ea0cbd 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -3584,7 +3584,7 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
flags |= TRACECMD_RECORD_NOBRASS;
else if (!trace_vsock_can_splice_read())
flags |= TRACECMD_RECORD_NOSPLICE;
- return tracecmd_create_recorder_virt(file, cpu, flags, fd);
+ return tracecmd_create_recorder_virt(file, cpu, flags, fd, max_kb);
}
if (brass)
next reply other threads:[~2024-03-07 12:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-07 12:15 Marcelo Tosatti [this message]
2024-03-12 4:12 ` [PATCH] trace-cmd: support -m parameter for virt instances Junyao Zhao
2024-05-13 17:46 ` Marcelo Tosatti
2024-05-13 17:50 ` Steven Rostedt
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