| Message ID | 20230213221835.592763-1-zwisler@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf-next,1/2] bpf: use canonical ftrace path | expand |
On 02/13, Ross Zwisler wrote: > The canonical location for the tracefs filesystem is at > /sys/kernel/tracing. > But, from Documentation/trace/ftrace.rst: > Before 4.1, all ftrace tracing control files were within the debugfs > file system, which is typically located at /sys/kernel/debug/tracing. > For backward compatibility, when mounting the debugfs file system, > the tracefs file system will be automatically mounted at: > /sys/kernel/debug/tracing > Many comments and samples in the bpf code still refer to this older > debugfs path, so let's update them to avoid confusion. There are a few > spots where the bpf code explicitly checks both tracefs and debugfs > (tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left > those alone so that the tools can continue to work with both paths. Doesn't seem to apply cleanly to bpf-next? https://github.com/kernel-patches/bpf/pull/4584 > Signed-off-by: Ross Zwisler <zwisler@google.com> > Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > [ Per Alexei's request, resending towards bpf-next ] > include/uapi/linux/bpf.h | 8 ++++---- > samples/bpf/cpustat_kern.c | 4 ++-- > samples/bpf/hbm.c | 4 ++-- > samples/bpf/ibumad_kern.c | 4 ++-- > samples/bpf/lwt_len_hist.sh | 2 +- > samples/bpf/offwaketime_kern.c | 2 +- > samples/bpf/task_fd_query_user.c | 4 ++-- > samples/bpf/test_lwt_bpf.sh | 2 +- > samples/bpf/test_overhead_tp_kern.c | 4 ++-- > tools/include/uapi/linux/bpf.h | 8 ++++---- > 10 files changed, 21 insertions(+), 21 deletions(-) > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 464ca3f01fe7..44387b31cbde 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -1642,17 +1642,17 @@ union bpf_attr { > * Description > * This helper is a "printk()-like" facility for debugging. It > * prints a message defined by format *fmt* (of size *fmt_size*) > - * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if > + * to file *\/sys/kernel/tracing/trace* from TraceFS, if > * available. It can take up to three additional **u64** > * arguments (as an eBPF helpers, the total number of arguments is > * limited to five). > * > * Each time the helper is called, it appends a line to the trace. > - * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is > - * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this. > + * Lines are discarded while *\/sys/kernel/tracing/trace* is > + * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. > * The format of the trace is customizable, and the exact output > * one will get depends on the options set in > - * *\/sys/kernel/debug/tracing/trace_options* (see also the > + * *\/sys/kernel/tracing/trace_options* (see also the > * *README* file under the same directory). However, it usually > * defaults to something like: > * > diff --git a/samples/bpf/cpustat_kern.c b/samples/bpf/cpustat_kern.c > index 5aefd19cdfa1..944f13fe164a 100644 > --- a/samples/bpf/cpustat_kern.c > +++ b/samples/bpf/cpustat_kern.c > @@ -76,8 +76,8 @@ struct { > /* > * The trace events for cpu_idle and cpu_frequency are taken from: > - * /sys/kernel/debug/tracing/events/power/cpu_idle/format > - * /sys/kernel/debug/tracing/events/power/cpu_frequency/format > + * /sys/kernel/tracing/events/power/cpu_idle/format > + * /sys/kernel/tracing/events/power/cpu_frequency/format > * > * These two events have same format, so define one common structure. > */ > diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c > index 516fbac28b71..ff58ec43f56a 100644 > --- a/samples/bpf/hbm.c > +++ b/samples/bpf/hbm.c > @@ -65,7 +65,7 @@ static void Usage(void); > static void read_trace_pipe2(void); > static void do_error(char *msg, bool errno_flag); > -#define DEBUGFS "/sys/kernel/debug/tracing/" > +#define TRACEFS "/sys/kernel/tracing/" > static struct bpf_program *bpf_prog; > static struct bpf_object *obj; > @@ -77,7 +77,7 @@ static void read_trace_pipe2(void) > FILE *outf; > char *outFname = "hbm_out.log"; > - trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0); > + trace_fd = open(TRACEFS "trace_pipe", O_RDONLY, 0); > if (trace_fd < 0) { > printf("Error opening trace_pipe\n"); > return; > diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c > index 9b193231024a..f07474c72525 100644 > --- a/samples/bpf/ibumad_kern.c > +++ b/samples/bpf/ibumad_kern.c > @@ -39,8 +39,8 @@ struct { > /* Taken from the current format defined in > * include/trace/events/ib_umad.h > * and > - * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format > - * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format > + * /sys/kernel/tracing/events/ib_umad/ib_umad_read/format > + * /sys/kernel/tracing/events/ib_umad/ib_umad_write/format > */ > struct ib_umad_rw_args { > u64 pad; > diff --git a/samples/bpf/lwt_len_hist.sh b/samples/bpf/lwt_len_hist.sh > index 0eda9754f50b..11fa0a087db6 100755 > --- a/samples/bpf/lwt_len_hist.sh > +++ b/samples/bpf/lwt_len_hist.sh > @@ -5,7 +5,7 @@ NS1=lwt_ns1 > VETH0=tst_lwt1a > VETH1=tst_lwt1b > -TRACE_ROOT=/sys/kernel/debug/tracing > +TRACE_ROOT=/sys/kernel/tracing > function cleanup { > # To reset saved histogram, remove pinned map > diff --git a/samples/bpf/offwaketime_kern.c > b/samples/bpf/offwaketime_kern.c > index eb4d94742e6b..23f12b47e9e5 100644 > --- a/samples/bpf/offwaketime_kern.c > +++ b/samples/bpf/offwaketime_kern.c > @@ -110,7 +110,7 @@ static inline int update_counts(void *ctx, u32 pid, > u64 delta) > } > #if 1 > -/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format > */ > +/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */ > struct sched_switch_args { > unsigned long long pad; > char prev_comm[TASK_COMM_LEN]; > diff --git a/samples/bpf/task_fd_query_user.c > b/samples/bpf/task_fd_query_user.c > index a33d74bd3a4b..1e61f2180470 100644 > --- a/samples/bpf/task_fd_query_user.c > +++ b/samples/bpf/task_fd_query_user.c > @@ -235,7 +235,7 @@ static int test_debug_fs_uprobe(char *binary_path, > long offset, bool is_return) > struct bpf_link *link; > ssize_t bytes; > - snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", > + snprintf(buf, sizeof(buf), "/sys/kernel/tracing/%s_events", > event_type); > kfd = open(buf, O_WRONLY | O_TRUNC, 0); > CHECK_PERROR_RET(kfd < 0); > @@ -252,7 +252,7 @@ static int test_debug_fs_uprobe(char *binary_path, > long offset, bool is_return) > close(kfd); > kfd = -1; > - snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id", > + snprintf(buf, sizeof(buf), "/sys/kernel/tracing/events/%ss/%s/id", > event_type, event_alias); > efd = open(buf, O_RDONLY, 0); > CHECK_PERROR_RET(efd < 0); > diff --git a/samples/bpf/test_lwt_bpf.sh b/samples/bpf/test_lwt_bpf.sh > index 65a976058dd3..db5691e6637f 100755 > --- a/samples/bpf/test_lwt_bpf.sh > +++ b/samples/bpf/test_lwt_bpf.sh > @@ -19,7 +19,7 @@ IPVETH3="192.168.111.2" > IP_LOCAL="192.168.99.1" > -TRACE_ROOT=/sys/kernel/debug/tracing > +TRACE_ROOT=/sys/kernel/tracing > function lookup_mac() > { > diff --git a/samples/bpf/test_overhead_tp_kern.c > b/samples/bpf/test_overhead_tp_kern.c > index 80edadacb692..a1d53b0d8476 100644 > --- a/samples/bpf/test_overhead_tp_kern.c > +++ b/samples/bpf/test_overhead_tp_kern.c > @@ -8,7 +8,7 @@ > #include <uapi/linux/bpf.h> > #include <bpf/bpf_helpers.h> > -/* from /sys/kernel/debug/tracing/events/task/task_rename/format */ > +/* from /sys/kernel/tracing/events/task/task_rename/format */ > struct task_rename { > __u64 pad; > __u32 pid; > @@ -22,7 +22,7 @@ int prog(struct task_rename *ctx) > return 0; > } > -/* from /sys/kernel/debug/tracing/events/random/urandom_read/format */ > +/* from /sys/kernel/tracing/events/random/urandom_read/format */ > struct urandom_read { > __u64 pad; > int got_bits; > diff --git a/tools/include/uapi/linux/bpf.h > b/tools/include/uapi/linux/bpf.h > index 464ca3f01fe7..44387b31cbde 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -1642,17 +1642,17 @@ union bpf_attr { > * Description > * This helper is a "printk()-like" facility for debugging. It > * prints a message defined by format *fmt* (of size *fmt_size*) > - * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if > + * to file *\/sys/kernel/tracing/trace* from TraceFS, if > * available. It can take up to three additional **u64** > * arguments (as an eBPF helpers, the total number of arguments is > * limited to five). > * > * Each time the helper is called, it appends a line to the trace. > - * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is > - * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this. > + * Lines are discarded while *\/sys/kernel/tracing/trace* is > + * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. > * The format of the trace is customizable, and the exact output > * one will get depends on the options set in > - * *\/sys/kernel/debug/tracing/trace_options* (see also the > + * *\/sys/kernel/tracing/trace_options* (see also the > * *README* file under the same directory). However, it usually > * defaults to something like: > * > -- > 2.39.1.581.gbfd45094c4-goog
On Mon, Feb 13, 2023 at 06:57:16PM -0800, Stanislav Fomichev wrote: > On 02/13, Ross Zwisler wrote: > > The canonical location for the tracefs filesystem is at > > /sys/kernel/tracing. > > > But, from Documentation/trace/ftrace.rst: > > > Before 4.1, all ftrace tracing control files were within the debugfs > > file system, which is typically located at /sys/kernel/debug/tracing. > > For backward compatibility, when mounting the debugfs file system, > > the tracefs file system will be automatically mounted at: > > > /sys/kernel/debug/tracing > > > Many comments and samples in the bpf code still refer to this older > > debugfs path, so let's update them to avoid confusion. There are a few > > spots where the bpf code explicitly checks both tracefs and debugfs > > (tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left > > those alone so that the tools can continue to work with both paths. > > Doesn't seem to apply cleanly to bpf-next? > > https://github.com/kernel-patches/bpf/pull/4584 Oh, apologies, I was using Linus's master branch as my baseline. I'll send out a v2.
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 464ca3f01fe7..44387b31cbde 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1642,17 +1642,17 @@ union bpf_attr { * Description * This helper is a "printk()-like" facility for debugging. It * prints a message defined by format *fmt* (of size *fmt_size*) - * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if + * to file *\/sys/kernel/tracing/trace* from TraceFS, if * available. It can take up to three additional **u64** * arguments (as an eBPF helpers, the total number of arguments is * limited to five). * * Each time the helper is called, it appends a line to the trace. - * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is - * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this. + * Lines are discarded while *\/sys/kernel/tracing/trace* is + * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. * The format of the trace is customizable, and the exact output * one will get depends on the options set in - * *\/sys/kernel/debug/tracing/trace_options* (see also the + * *\/sys/kernel/tracing/trace_options* (see also the * *README* file under the same directory). However, it usually * defaults to something like: * diff --git a/samples/bpf/cpustat_kern.c b/samples/bpf/cpustat_kern.c index 5aefd19cdfa1..944f13fe164a 100644 --- a/samples/bpf/cpustat_kern.c +++ b/samples/bpf/cpustat_kern.c @@ -76,8 +76,8 @@ struct { /* * The trace events for cpu_idle and cpu_frequency are taken from: - * /sys/kernel/debug/tracing/events/power/cpu_idle/format - * /sys/kernel/debug/tracing/events/power/cpu_frequency/format + * /sys/kernel/tracing/events/power/cpu_idle/format + * /sys/kernel/tracing/events/power/cpu_frequency/format * * These two events have same format, so define one common structure. */ diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c index 516fbac28b71..ff58ec43f56a 100644 --- a/samples/bpf/hbm.c +++ b/samples/bpf/hbm.c @@ -65,7 +65,7 @@ static void Usage(void); static void read_trace_pipe2(void); static void do_error(char *msg, bool errno_flag); -#define DEBUGFS "/sys/kernel/debug/tracing/" +#define TRACEFS "/sys/kernel/tracing/" static struct bpf_program *bpf_prog; static struct bpf_object *obj; @@ -77,7 +77,7 @@ static void read_trace_pipe2(void) FILE *outf; char *outFname = "hbm_out.log"; - trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0); + trace_fd = open(TRACEFS "trace_pipe", O_RDONLY, 0); if (trace_fd < 0) { printf("Error opening trace_pipe\n"); return; diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c index 9b193231024a..f07474c72525 100644 --- a/samples/bpf/ibumad_kern.c +++ b/samples/bpf/ibumad_kern.c @@ -39,8 +39,8 @@ struct { /* Taken from the current format defined in * include/trace/events/ib_umad.h * and - * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format - * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format + * /sys/kernel/tracing/events/ib_umad/ib_umad_read/format + * /sys/kernel/tracing/events/ib_umad/ib_umad_write/format */ struct ib_umad_rw_args { u64 pad; diff --git a/samples/bpf/lwt_len_hist.sh b/samples/bpf/lwt_len_hist.sh index 0eda9754f50b..11fa0a087db6 100755 --- a/samples/bpf/lwt_len_hist.sh +++ b/samples/bpf/lwt_len_hist.sh @@ -5,7 +5,7 @@ NS1=lwt_ns1 VETH0=tst_lwt1a VETH1=tst_lwt1b -TRACE_ROOT=/sys/kernel/debug/tracing +TRACE_ROOT=/sys/kernel/tracing function cleanup { # To reset saved histogram, remove pinned map diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c index eb4d94742e6b..23f12b47e9e5 100644 --- a/samples/bpf/offwaketime_kern.c +++ b/samples/bpf/offwaketime_kern.c @@ -110,7 +110,7 @@ static inline int update_counts(void *ctx, u32 pid, u64 delta) } #if 1 -/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ +/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */ struct sched_switch_args { unsigned long long pad; char prev_comm[TASK_COMM_LEN]; diff --git a/samples/bpf/task_fd_query_user.c b/samples/bpf/task_fd_query_user.c index a33d74bd3a4b..1e61f2180470 100644 --- a/samples/bpf/task_fd_query_user.c +++ b/samples/bpf/task_fd_query_user.c @@ -235,7 +235,7 @@ static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return) struct bpf_link *link; ssize_t bytes; - snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events", + snprintf(buf, sizeof(buf), "/sys/kernel/tracing/%s_events", event_type); kfd = open(buf, O_WRONLY | O_TRUNC, 0); CHECK_PERROR_RET(kfd < 0); @@ -252,7 +252,7 @@ static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return) close(kfd); kfd = -1; - snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id", + snprintf(buf, sizeof(buf), "/sys/kernel/tracing/events/%ss/%s/id", event_type, event_alias); efd = open(buf, O_RDONLY, 0); CHECK_PERROR_RET(efd < 0); diff --git a/samples/bpf/test_lwt_bpf.sh b/samples/bpf/test_lwt_bpf.sh index 65a976058dd3..db5691e6637f 100755 --- a/samples/bpf/test_lwt_bpf.sh +++ b/samples/bpf/test_lwt_bpf.sh @@ -19,7 +19,7 @@ IPVETH3="192.168.111.2" IP_LOCAL="192.168.99.1" -TRACE_ROOT=/sys/kernel/debug/tracing +TRACE_ROOT=/sys/kernel/tracing function lookup_mac() { diff --git a/samples/bpf/test_overhead_tp_kern.c b/samples/bpf/test_overhead_tp_kern.c index 80edadacb692..a1d53b0d8476 100644 --- a/samples/bpf/test_overhead_tp_kern.c +++ b/samples/bpf/test_overhead_tp_kern.c @@ -8,7 +8,7 @@ #include <uapi/linux/bpf.h> #include <bpf/bpf_helpers.h> -/* from /sys/kernel/debug/tracing/events/task/task_rename/format */ +/* from /sys/kernel/tracing/events/task/task_rename/format */ struct task_rename { __u64 pad; __u32 pid; @@ -22,7 +22,7 @@ int prog(struct task_rename *ctx) return 0; } -/* from /sys/kernel/debug/tracing/events/random/urandom_read/format */ +/* from /sys/kernel/tracing/events/random/urandom_read/format */ struct urandom_read { __u64 pad; int got_bits; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 464ca3f01fe7..44387b31cbde 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1642,17 +1642,17 @@ union bpf_attr { * Description * This helper is a "printk()-like" facility for debugging. It * prints a message defined by format *fmt* (of size *fmt_size*) - * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if + * to file *\/sys/kernel/tracing/trace* from TraceFS, if * available. It can take up to three additional **u64** * arguments (as an eBPF helpers, the total number of arguments is * limited to five). * * Each time the helper is called, it appends a line to the trace. - * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is - * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this. + * Lines are discarded while *\/sys/kernel/tracing/trace* is + * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. * The format of the trace is customizable, and the exact output * one will get depends on the options set in - * *\/sys/kernel/debug/tracing/trace_options* (see also the + * *\/sys/kernel/tracing/trace_options* (see also the * *README* file under the same directory). However, it usually * defaults to something like: *