Commit 72fd2efb authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

tcg: distribute tcg_time into TCG contexts 



When we implemented per-vCPU TCG contexts, we forgot to also
distribute the tcg_time counter, which has remained as a global
accessed without any serialization, leading to potentially missed
counts.

Fix it by distributing the field over the TCG contexts, embedding
it into TCGProfile with a field called "cpu_exec_time", which is more
descriptive than "tcg_time". Add a function to query this value
directly, and for completeness, fill in the field in
tcg_profile_snapshot, even though its callers do not use it.

Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Message-Id: <20181010144853.13005-5-cota@braap.org>
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
parent dd1d7da2

cpus.c

+2 −1
Original line number Diff line number Diff line
@@ -1425,7 +1425,8 @@ static int tcg_cpu_exec(CPUState *cpu) 
    ret = cpu_exec(cpu);

    cpu_exec_end(cpu);

#ifdef CONFIG_PROFILER

    tcg_time += profile_getclock() - ti;

    atomic_set(&tcg_ctx->prof.cpu_exec_time,

               tcg_ctx->prof.cpu_exec_time + profile_getclock() - ti);

#endif

    return ret;

}

include/qemu/timer.h

+0 −1
Original line number Diff line number Diff line
@@ -1046,7 +1046,6 @@ static inline int64_t profile_getclock(void) 
    return get_clock();

}



extern int64_t tcg_time;

extern int64_t dev_time;

#endif

monitor.c

+10 −3
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ 
#include "sysemu/cpus.h"

#include "sysemu/iothread.h"

#include "qemu/cutils.h"

#include "tcg/tcg.h"



#if defined(TARGET_S390X)

#include "hw/s390x/storage-keys.h"
@@ -1966,16 +1967,22 @@ static void hmp_info_numa(Monitor *mon, const QDict *qdict) 


#ifdef CONFIG_PROFILER



int64_t tcg_time;

int64_t dev_time;



static void hmp_info_profile(Monitor *mon, const QDict *qdict)

{

    static int64_t last_cpu_exec_time;

    int64_t cpu_exec_time;

    int64_t delta;



    cpu_exec_time = tcg_cpu_exec_time();

    delta = cpu_exec_time - last_cpu_exec_time;



    monitor_printf(mon, "async time  %" PRId64 " (%0.3f)\n",

                   dev_time, dev_time / (double)NANOSECONDS_PER_SECOND);

    monitor_printf(mon, "qemu time   %" PRId64 " (%0.3f)\n",

                   tcg_time, tcg_time / (double)NANOSECONDS_PER_SECOND);

    tcg_time = 0;

                   delta, delta / (double)NANOSECONDS_PER_SECOND);

    last_cpu_exec_time = cpu_exec_time;

    dev_time = 0;

}

#else

tcg/tcg.c

+23 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
/* Define to jump the ELF file used to communicate with GDB.  */

#undef DEBUG_JIT



#include "qemu/error-report.h"

#include "qemu/cutils.h"

#include "qemu/host-utils.h"

#include "qemu/timer.h"
@@ -3361,6 +3362,7 @@ void tcg_profile_snapshot(TCGProfile *prof, bool counters, bool table) 
        const TCGProfile *orig = &s->prof;



        if (counters) {

            PROF_ADD(prof, orig, cpu_exec_time);

            PROF_ADD(prof, orig, tb_count1);

            PROF_ADD(prof, orig, tb_count);

            PROF_ADD(prof, orig, op_count);
@@ -3412,11 +3414,32 @@ void tcg_dump_op_count(FILE *f, fprintf_function cpu_fprintf) 
                    prof.table_op_count[i]);

    }

}



int64_t tcg_cpu_exec_time(void)

{

    unsigned int n_ctxs = atomic_read(&n_tcg_ctxs);

    unsigned int i;

    int64_t ret = 0;



    for (i = 0; i < n_ctxs; i++) {

        const TCGContext *s = atomic_read(&tcg_ctxs[i]);

        const TCGProfile *prof = &s->prof;



        ret += atomic_read(&prof->cpu_exec_time);

    }

    return ret;

}

#else

void tcg_dump_op_count(FILE *f, fprintf_function cpu_fprintf)

{

    cpu_fprintf(f, "[TCG profiler not compiled]\n");

}



int64_t tcg_cpu_exec_time(void)

{

    error_report("%s: TCG profiler not compiled", __func__);

    exit(EXIT_FAILURE);

}

#endif

tcg/tcg.h

+2 −0
Original line number Diff line number Diff line
@@ -629,6 +629,7 @@ typedef struct TCGOp { 
QEMU_BUILD_BUG_ON(NB_OPS > (1 << 8));



typedef struct TCGProfile {

    int64_t cpu_exec_time;

    int64_t tb_count1;

    int64_t tb_count;

    int64_t op_count; /* total insn count */
@@ -1002,6 +1003,7 @@ int tcg_check_temp_count(void); 
#define tcg_check_temp_count() 0

#endif



int64_t tcg_cpu_exec_time(void);

void tcg_dump_info(FILE *f, fprintf_function cpu_fprintf);

void tcg_dump_op_count(FILE *f, fprintf_function cpu_fprintf);