get rid of dynamic memory allocation for scopedperf,

which allows moving initsperf() to before initkalloc().

get rid of dynamic memory allocation for scopedperf,
10a20d0c · Nickolai Zeldovich · 3ae1d7bd · 10a20d0c · 10a20d0c · 10a20d0c
--- a/include/scopedperf.hh
+++ b/include/scopedperf.hh
@@ -409,6 +409,7 @@ class tsc_ctr : public namedctr<64> {
    __asm __volatile("rdtsc" : "=a" (a), "=d" (d));
    return a | (d << 32);
  }
+  NEW_DELETE_OPS(tsc_ctr)
 };

 class tscp_ctr : public namedctr<64> {

--- a/include/sperf.hh
+++ b/include/sperf.hh
 #pragma once

 #include "scopedperf.hh"
-extern scopedperf::ctrgroup_chain<scopedperf::tsc_ctr> *perfgroup;
+extern scopedperf::ctrgroup_chain<scopedperf::tsc_ctr> perfgroup;

--- a/kernel/main.cc
+++ b/kernel/main.cc
@@ -76,11 +76,11 @@ cmain(u64 mbmagic, u64 mbaddr)
  inituart();
  initcga();
  initconsole();
+  initsperf();
  inittrap();
  initmp();
  initlapic();
  initkalloc(mbaddr);
-  initsperf();
  initproc();      // process table
  initsched();     // scheduler run queues
  initgc();        // gc epochs and threads

--- a/kernel/sperf.cc
+++ b/kernel/sperf.cc
@@ -7,11 +7,13 @@

 using namespace scopedperf;

-ctrgroup_chain<tsc_ctr> *perfgroup;
+static tsc_ctr tsc;
+ctrgroup_chain<tsc_ctr> perfgroup(&tsc);
+// but xv6 doesn't run static constructors, so call them explicitly below..

 void
 initsperf()
 {
-  static tsc_ctr tsc;
-  perfgroup = new ctrgroup_chain<tsc_ctr>(&tsc);
+  new (&tsc) tsc_ctr();
+  new (&perfgroup) ctrgroup_chain<tsc_ctr>(&tsc);
 }
--- a/kernel/sysproc.cc
+++ b/kernel/sysproc.cc
@@ -86,7 +86,7 @@ sys_uptime(void)
 long
 sys_map(uptr addr, u64 len)
 {
-  ANON_REGION(__func__, perfgroup);
+  ANON_REGION(__func__, &perfgroup);

  vmnode *vmn = new vmnode(PGROUNDUP(len) / PGSIZE);
  if (vmn == 0)
@@ -103,7 +103,7 @@ sys_map(uptr addr, u64 len)
 long
 sys_unmap(uptr addr, u64 len)
 {
-  ANON_REGION(__func__, perfgroup);
+  ANON_REGION(__func__, &perfgroup);

  uptr align_addr = PGROUNDDOWN(addr);
  uptr align_len = PGROUNDUP(addr + len) - align_addr;

--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -274,7 +274,7 @@ vmap::lookup(uptr start, uptr len)
 int
 vmap::insert(vmnode *n, uptr vma_start, int dotlb)
 {
-  ANON_REGION("vmap::insert", perfgroup);
+  ANON_REGION("vmap::insert", &perfgroup);

  vma *e;