Merge pull request #346 from brendangregg/master

biosnoop.py: use one map instead of two

tools/biosnoop.py

@@ -21,23 +21,21 @@ b = BPF(text="""
 #include <linux/blkdev.h>
 
 struct val_t {
+    u32 pid;
     char name[TASK_COMM_LEN];
 };
 
 BPF_HASH(start, struct request *);
-BPF_HASH(pidbyreq, struct request *, u32);
-BPF_HASH(commbyreq, struct request *, struct val_t);
+BPF_HASH(infobyreq, struct request *, struct val_t);
 
 // cache PID and comm by-req
 int trace_pid_start(struct pt_regs *ctx, struct request *req)
 {
-    u32 pid;
     struct val_t val = {};
 
-    pid = bpf_get_current_pid_tgid();
-    pidbyreq.update(&req, &pid);
     if (bpf_get_current_comm(&val.name, sizeof(val.name)) == 0) {
-        commbyreq.update(&req, &val);
+        val.pid = bpf_get_current_pid_tgid();
+        infobyreq.update(&req, &val);
     }
 
     return 0;
@@ -74,12 +72,11 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)
     // As bpf_trace_prink() is limited to a maximum of 1 string and 2
     // integers, we'll use more than one to output the data.
     //
-    valp = commbyreq.lookup(&req);
-    pidp = pidbyreq.lookup(&req);
-    if (pidp == 0 || valp == 0) {
+    valp = infobyreq.lookup(&req);
+    if (valp == 0) {
         bpf_trace_printk("0 0 ? %d\\n", req->__data_len);
     } else {
-        bpf_trace_printk("0 %d %s %d\\n", *pidp, valp->name,
+        bpf_trace_printk("0 %d %s %d\\n", valp->pid, valp->name,
             req->__data_len);
     }
 
@@ -93,8 +90,7 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)
     }
 
     start.delete(&req);
-    pidbyreq.delete(&req);
-    commbyreq.delete(&req);
+    infobyreq.delete(&req);
 
     return 0;
 }

tools/bitesize.py

@@ -4,8 +4,8 @@
 #               For Linux, uses BCC, eBPF. See .c file.
 #
 # USAGE: bitesize
-# Ctrl-C will print the partially gathered histogram then exit.
 #
+# Ctrl-C will print the partially gathered histogram then exit.
 #
 # Copyright (c) 2016 Allan McAleavy
 # Licensed under the Apache License, Version 2.0 (the "License")
@@ -19,7 +19,7 @@ bpf_text = """
 #include <uapi/linux/ptrace.h>
 #include <linux/blkdev.h>
 
-struct proc_key_t  {
+struct proc_key_t {
     char name[TASK_COMM_LEN];
     u64 slot;
 };
@@ -41,12 +41,12 @@ int trace_pid_start(struct pt_regs *ctx, struct request *req)
     return 0;
 }
 
-int do_count (struct pt_regs *ctx, struct request *req)
+int do_count(struct pt_regs *ctx, struct request *req)
 {
     struct val_t *valp;
 
     valp = commbyreq.lookup(&req);
-    if ( valp ==  0) {
+    if (valp == 0) {
        return 0;
     }
 
@@ -55,7 +55,7 @@ int do_count (struct pt_regs *ctx, struct request *req)
         bpf_probe_read(&key.name, sizeof(key.name),valp->name);
         dist.increment(key);
     }
-       return 0;
+    return 0;
 }
 """
 
@@ -72,4 +72,4 @@ dist = b.get_table("dist")
 try:
     sleep(99999999)
 except KeyboardInterrupt:
-    dist.print_log2_hist("Kbytes", "Process Name:")
+    dist.print_log2_hist("Kbytes", "Process Name")

tools/bitesize_example.txt

-Example of BCC tool bitesize.py
+Examples of bitesize.py, the Linux bcc/eBPF version.
+
 
 The aim of this tool is to show I/O distribution for requested block sizes, by process name.
 
@@ -6,13 +7,13 @@ The aim of this tool is to show I/O distribution for requested block sizes, by p
 Tracing... Hit Ctrl-C to end.
 ^C
 
-Process Name: = 'kworker/u128:1'
+Process Name = 'kworker/u128:1'
      Kbytes              : count     distribution
          0 -> 1          : 1        |********************                    |
          2 -> 3          : 0        |                                        |
          4 -> 7          : 2        |****************************************|
 
-Process Name: = 'bitesize.py'
+Process Name = 'bitesize.py'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
@@ -23,7 +24,7 @@ Process Name: = 'bitesize.py'
         64 -> 127        : 0        |                                        |
        128 -> 255        : 1        |****************************************|
 
-Process Name: = 'dd'
+Process Name = 'dd'
      Kbytes              : count     distribution
          0 -> 1          : 3        |                                        |
          2 -> 3          : 0        |                                        |
@@ -37,13 +38,13 @@ Process Name: = 'dd'
        512 -> 1023       : 0        |                                        |
       1024 -> 2047       : 488      |****************************************|
 
-Process Name: = 'jbd2/dm-1-8'
+Process Name = 'jbd2/dm-1-8'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
          4 -> 7          : 1        |****************************************|
 
-Process Name: = 'cat'
+Process Name = 'cat'
      Kbytes              : count     distribution
          0 -> 1          : 1        |                                        |
          2 -> 3          : 0        |                                        |
@@ -55,19 +56,19 @@ Process Name: = 'cat'
        128 -> 255        : 0        |                                        |
        256 -> 511        : 1924     |****************************************|
 
-Process Name: = 'ntpd'
+Process Name = 'ntpd'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
          4 -> 7          : 104      |****************************************|
 
-Process Name: = 'vmtoolsd'
+Process Name = 'vmtoolsd'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
          4 -> 7          : 1        |****************************************|
 
-Process Name: = 'bash'
+Process Name = 'bash'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
@@ -75,7 +76,7 @@ Process Name: = 'bash'
          8 -> 15         : 0        |                                        |
         16 -> 31         : 2        |****************************************|
 
-Process Name: = 'jbd2/sdb-8'
+Process Name = 'jbd2/sdb-8'
      Kbytes              : count     distribution
          0 -> 1          : 0        |                                        |
          2 -> 3          : 0        |                                        |
@@ -86,7 +87,3 @@ Process Name: = 'jbd2/sdb-8'
 
 We can see from above that there was a dd command being run which generated 488 IOPS between 1MB and 2MB, we can also see the
 cat command generating 1924 IOPS between 256Kb and 512Kb.
-
-
-See also systemtap version:
-https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp