Merge branch 'fix-perf-bug' into 'master'

Fix perf bug

See merge request projectn/nemu!113

src/cpu/tcache.c

@@ -15,7 +15,7 @@ typedef struct bb_t {
 static Decode tcache_pool[TCACHE_SIZE] = {};
 static int tc_idx = 0;
 static Decode tcache_tmp_pool[TCACHE_TMP_SIZE] = {};
-static bool tcache_tmp_bitmap[TCACHE_TMP_SIZE] = {};
+static Decode *tcache_tmp_freelist = NULL;
 static bb_t bb_pool[BB_POOL_SIZE] = {};
 static int bb_idx = 0;
 static bb_t bb_list [BB_LIST_SIZE] = {};
@@ -26,7 +26,7 @@ static const void* get_nemu_decode() {
 }
 
 static inline Decode* tcache_entry_init(Decode *s, vaddr_t pc) {
-  memset(s, 0, sizeof(*s));
+  s->tnext = s->ntnext = NULL;
   s->pc = pc;
   s->EHelper = get_nemu_decode();
   return s;
@@ -35,26 +35,37 @@ static inline Decode* tcache_entry_init(Decode *s, vaddr_t pc) {
 static inline Decode* tcache_new(vaddr_t pc) {
   if (tc_idx == TCACHE_SIZE) return NULL;
   assert(tc_idx < TCACHE_SIZE);
-  tcache_entry_init(&tcache_pool[tc_idx], pc);
-  return &tcache_pool[tc_idx ++];
+  Decode *s = &tcache_pool[tc_idx];
+  tc_idx ++;
+  return tcache_entry_init(s, pc);
 }
 
+#ifdef DEBUG
+#define tcache_tmp_check(s) do { \
+  int idx = s - tcache_tmp_pool; \
+  Assert(idx >= 0 && idx < TCACHE_TMP_SIZE, "idx = %d, s = %p", idx, s); \
+} while (0)
+#else
+#define tcache_tmp_check(s)
+#endif
+
 static inline Decode* tcache_tmp_new(vaddr_t pc) {
-  int i;
-  for (i = 0; i < TCACHE_TMP_SIZE; i ++) {
-    if (tcache_tmp_bitmap[i] == 0) {
-      tcache_tmp_bitmap[i] = 1;
-      return tcache_entry_init(&tcache_tmp_pool[i], pc);
-    }
-  }
-  assert(0);
-  return NULL;
+  Decode *s = tcache_tmp_freelist;
+  assert(s != NULL);
+  tcache_tmp_check(s);
+  tcache_tmp_check(tcache_tmp_freelist->tnext);
+  tcache_tmp_freelist = tcache_tmp_freelist->tnext;
+  tcache_tmp_check(tcache_tmp_freelist);
+  tcache_tmp_check(tcache_tmp_freelist->tnext);
+  return tcache_entry_init(s, pc);
 }
 
 static inline void tcache_tmp_free(Decode *s) {
-  int idx = s - tcache_tmp_pool;
-  assert(idx >= 0 && idx < TCACHE_TMP_SIZE);
-  tcache_tmp_bitmap[idx] = 0;
+  tcache_tmp_check(s);
+  tcache_tmp_check(tcache_tmp_freelist);
+  s->tnext = tcache_tmp_freelist;
+  tcache_tmp_freelist = s;
+  tcache_tmp_check(tcache_tmp_freelist->tnext);
 }
 
 
@@ -124,7 +135,13 @@ static void tcache_flush() {
   tc_idx = 0;
   bb_idx = 0;
   memset(bb_list, -1, sizeof(bb_list));
-  memset(tcache_tmp_bitmap, 0, sizeof(tcache_tmp_bitmap));
+
+  int i;
+  for (i = 0; i < TCACHE_TMP_SIZE - 1; i ++) {
+    tcache_tmp_pool[i].tnext = &tcache_tmp_pool[i + 1];
+  }
+  tcache_tmp_pool[TCACHE_TMP_SIZE - 1].tnext = NULL;
+  tcache_tmp_freelist = &tcache_tmp_pool[0];
 }
 
 enum { TCACHE_BB_BUILDING, TCACHE_RUNNING };
@@ -161,13 +178,14 @@ Decode* tcache_decode(Decode *s, const void **exec_table) {
   s->EHelper = exec_table[idx];
 
   if (bb_start) {
-    s = tcache_new(old->pc);
+    vaddr_t thispc = old->pc;
+    s = tcache_new(thispc);
     if (s == NULL) goto full;
-    bb_t *ret = bb_insert(old->pc, s);
+    bb_t *ret = bb_insert(thispc, s);
     if (ret == NULL) { // basic block list is full
-full: old->EHelper = get_nemu_decode(); // decode again
-      save_globals(old);
-      tcache_flush();
+full: tcache_flush();
+      s = tcache_tmp_new(thispc); // decode again
+      save_globals(s);
       longjmp_exec(NEMU_EXEC_AGAIN);
     }
 

src/isa/riscv64/clint.c

@@ -21,6 +21,11 @@ void update_clint() {
   mip->mtip = (clint_base[CLINT_MTIME] >= clint_base[CLINT_MTIMECMP]);
 }
 
+uint64_t clint_uptime() {
+  update_clint();
+  return clint_base[CLINT_MTIME];
+}
+
 static void clint_io_handler(uint32_t offset, int len, bool is_write) {
   update_clint();
 }

src/isa/riscv64/local-include/csr.h

@@ -16,7 +16,8 @@
   f(sscratch   , 0x140) f(sepc       , 0x141) f(scause     , 0x142) \
   f(stval      , 0x143) f(sip        , 0x144) \
   f(satp       , 0x180) \
-  f(fflags     , 0x001) f(frm        , 0x002) f(fcsr       , 0x003)
+  f(fflags     , 0x001) f(frm        , 0x002) f(fcsr       , 0x003) \
+  f(mtime      , 0xc01)
 
 #define CSR_STRUCT_START(name) \
   typedef union { \
@@ -220,6 +221,9 @@ CSR_STRUCT_START(fcsr)
   };
 CSR_STRUCT_END(fcsr)
 
+CSR_STRUCT_START(mtime)
+CSR_STRUCT_END(mtime)
+
 #define CSRS_DECL(name, addr) extern concat(name, _t)* const name;
 MAP(CSRS, CSRS_DECL)
 

src/isa/riscv64/system/priv.c

@@ -1,9 +1,9 @@
 #include "../local-include/csr.h"
 #include "../local-include/rtl.h"
-#include "../local-include/intr.h"
 #include <cpu/cpu.h>
 
 int update_mmu_state();
+uint64_t clint_uptime();
 
 static word_t csr_array[4096] = {};
 
@@ -39,6 +39,7 @@ static inline word_t csr_read(word_t *src) {
   else if (is_read(fcsr))   { return fcsr->val & FCSR_MASK; }
   else if (is_read(fflags)) { return fcsr->fflags.val; }
   else if (is_read(frm))    { return fcsr->frm; }
+  else if (is_read(mtime))  { return clint_uptime(); }
   return *src;
 }
 
@@ -76,7 +77,6 @@ word_t csrid_read(uint32_t csrid) {
 }
 
 static void csrrw(rtlreg_t *dest, const rtlreg_t *src, uint32_t csrid) {
-  if (csrid == 0xc01) { longjmp_exception(EX_II); } // time
   word_t *csr = csr_decode(csrid);
   word_t tmp = (src != NULL ? *src : 0);
   if (dest != NULL) { *dest = csr_read(csr); }