| Message ID | 20240618112649.76683-1-cleger@rivosinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] target/riscv: fix instructions count handling in icount mode | expand |
On Tue, Jun 18, 2024 at 4:27 AM Clément Léger <cleger@rivosinc.com> wrote: > > When icount is enabled, rather than returning the virtual CPU time, we > should return the instruction count itself. Add an instructions bool > parameter to get_ticks() to correctly return icount_get_raw() when > icount_enabled() == 1 and instruction count is queried. This will modify > the existing behavior which was returning an instructions count close to > the number of cycles (CPI ~= 1). > > Signed-off-by: Clément Léger <cleger@rivosinc.com> > > --- > > v2: > - Apply checkpatch and fixed missing braces > As the changes were minor, you can keep the RB tag. Anyways, Reviewed-by: Atish Patra <atishp@rivosinc.com> > --- > target/riscv/csr.c | 30 +++++++++++++++++------------- > 1 file changed, 17 insertions(+), 13 deletions(-) > > diff --git a/target/riscv/csr.c b/target/riscv/csr.c > index 58ef7079dc..b8915e32a2 100644 > --- a/target/riscv/csr.c > +++ b/target/riscv/csr.c > @@ -762,14 +762,18 @@ static RISCVException write_vcsr(CPURISCVState *env, int csrno, > } > > /* User Timers and Counters */ > -static target_ulong get_ticks(bool shift) > +static target_ulong get_ticks(bool shift, bool instructions) > { > int64_t val; > target_ulong result; > > #if !defined(CONFIG_USER_ONLY) > if (icount_enabled()) { > - val = icount_get(); > + if (instructions) { > + val = icount_get_raw(); > + } else { > + val = icount_get(); > + } > } else { > val = cpu_get_host_ticks(); > } > @@ -804,14 +808,14 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, > static RISCVException read_hpmcounter(CPURISCVState *env, int csrno, > target_ulong *val) > { > - *val = get_ticks(false); > + *val = get_ticks(false, (csrno == CSR_INSTRET)); > return RISCV_EXCP_NONE; > } > > static RISCVException read_hpmcounterh(CPURISCVState *env, int csrno, > target_ulong *val) > { > - *val = get_ticks(true); > + *val = get_ticks(true, (csrno == CSR_INSTRETH)); > return RISCV_EXCP_NONE; > } > > @@ -875,11 +879,11 @@ static RISCVException write_mhpmcounter(CPURISCVState *env, int csrno, > int ctr_idx = csrno - CSR_MCYCLE; > PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; > uint64_t mhpmctr_val = val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > counter->mhpmcounter_val = val; > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - counter->mhpmcounter_prev = get_ticks(false); > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + counter->mhpmcounter_prev = get_ticks(false, instr); > if (ctr_idx > 2) { > if (riscv_cpu_mxl(env) == MXL_RV32) { > mhpmctr_val = mhpmctr_val | > @@ -902,12 +906,12 @@ static RISCVException write_mhpmcounterh(CPURISCVState *env, int csrno, > PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; > uint64_t mhpmctr_val = counter->mhpmcounter_val; > uint64_t mhpmctrh_val = val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > counter->mhpmcounterh_val = val; > mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32); > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - counter->mhpmcounterh_prev = get_ticks(true); > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + counter->mhpmcounterh_prev = get_ticks(true, instr); > if (ctr_idx > 2) { > riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx); > } > @@ -926,6 +930,7 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, > counter->mhpmcounter_prev; > target_ulong ctr_val = upper_half ? counter->mhpmcounterh_val : > counter->mhpmcounter_val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > if (get_field(env->mcountinhibit, BIT(ctr_idx))) { > /* > @@ -946,9 +951,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, > * The kernel computes the perf delta by subtracting the current value from > * the value it initialized previously (ctr_val). > */ > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - *val = get_ticks(upper_half) - ctr_prev + ctr_val; > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + *val = get_ticks(upper_half, instr) - ctr_prev + ctr_val; > } else { > *val = ctr_val; > } > -- > 2.45.2 >
On Tue, Jun 18, 2024 at 9:28 PM Clément Léger <cleger@rivosinc.com> wrote: > > When icount is enabled, rather than returning the virtual CPU time, we > should return the instruction count itself. Add an instructions bool > parameter to get_ticks() to correctly return icount_get_raw() when > icount_enabled() == 1 and instruction count is queried. This will modify > the existing behavior which was returning an instructions count close to > the number of cycles (CPI ~= 1). > > Signed-off-by: Clément Léger <cleger@rivosinc.com> Thanks! Applied to riscv-to-apply.next Alistair > > --- > > v2: > - Apply checkpatch and fixed missing braces > > --- > target/riscv/csr.c | 30 +++++++++++++++++------------- > 1 file changed, 17 insertions(+), 13 deletions(-) > > diff --git a/target/riscv/csr.c b/target/riscv/csr.c > index 58ef7079dc..b8915e32a2 100644 > --- a/target/riscv/csr.c > +++ b/target/riscv/csr.c > @@ -762,14 +762,18 @@ static RISCVException write_vcsr(CPURISCVState *env, int csrno, > } > > /* User Timers and Counters */ > -static target_ulong get_ticks(bool shift) > +static target_ulong get_ticks(bool shift, bool instructions) > { > int64_t val; > target_ulong result; > > #if !defined(CONFIG_USER_ONLY) > if (icount_enabled()) { > - val = icount_get(); > + if (instructions) { > + val = icount_get_raw(); > + } else { > + val = icount_get(); > + } > } else { > val = cpu_get_host_ticks(); > } > @@ -804,14 +808,14 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, > static RISCVException read_hpmcounter(CPURISCVState *env, int csrno, > target_ulong *val) > { > - *val = get_ticks(false); > + *val = get_ticks(false, (csrno == CSR_INSTRET)); > return RISCV_EXCP_NONE; > } > > static RISCVException read_hpmcounterh(CPURISCVState *env, int csrno, > target_ulong *val) > { > - *val = get_ticks(true); > + *val = get_ticks(true, (csrno == CSR_INSTRETH)); > return RISCV_EXCP_NONE; > } > > @@ -875,11 +879,11 @@ static RISCVException write_mhpmcounter(CPURISCVState *env, int csrno, > int ctr_idx = csrno - CSR_MCYCLE; > PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; > uint64_t mhpmctr_val = val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > counter->mhpmcounter_val = val; > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - counter->mhpmcounter_prev = get_ticks(false); > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + counter->mhpmcounter_prev = get_ticks(false, instr); > if (ctr_idx > 2) { > if (riscv_cpu_mxl(env) == MXL_RV32) { > mhpmctr_val = mhpmctr_val | > @@ -902,12 +906,12 @@ static RISCVException write_mhpmcounterh(CPURISCVState *env, int csrno, > PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; > uint64_t mhpmctr_val = counter->mhpmcounter_val; > uint64_t mhpmctrh_val = val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > counter->mhpmcounterh_val = val; > mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32); > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - counter->mhpmcounterh_prev = get_ticks(true); > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + counter->mhpmcounterh_prev = get_ticks(true, instr); > if (ctr_idx > 2) { > riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx); > } > @@ -926,6 +930,7 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, > counter->mhpmcounter_prev; > target_ulong ctr_val = upper_half ? counter->mhpmcounterh_val : > counter->mhpmcounter_val; > + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); > > if (get_field(env->mcountinhibit, BIT(ctr_idx))) { > /* > @@ -946,9 +951,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, > * The kernel computes the perf delta by subtracting the current value from > * the value it initialized previously (ctr_val). > */ > - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || > - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { > - *val = get_ticks(upper_half) - ctr_prev + ctr_val; > + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { > + *val = get_ticks(upper_half, instr) - ctr_prev + ctr_val; > } else { > *val = ctr_val; > } > -- > 2.45.2 > >
diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 58ef7079dc..b8915e32a2 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -762,14 +762,18 @@ static RISCVException write_vcsr(CPURISCVState *env, int csrno, } /* User Timers and Counters */ -static target_ulong get_ticks(bool shift) +static target_ulong get_ticks(bool shift, bool instructions) { int64_t val; target_ulong result; #if !defined(CONFIG_USER_ONLY) if (icount_enabled()) { - val = icount_get(); + if (instructions) { + val = icount_get_raw(); + } else { + val = icount_get(); + } } else { val = cpu_get_host_ticks(); } @@ -804,14 +808,14 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, static RISCVException read_hpmcounter(CPURISCVState *env, int csrno, target_ulong *val) { - *val = get_ticks(false); + *val = get_ticks(false, (csrno == CSR_INSTRET)); return RISCV_EXCP_NONE; } static RISCVException read_hpmcounterh(CPURISCVState *env, int csrno, target_ulong *val) { - *val = get_ticks(true); + *val = get_ticks(true, (csrno == CSR_INSTRETH)); return RISCV_EXCP_NONE; } @@ -875,11 +879,11 @@ static RISCVException write_mhpmcounter(CPURISCVState *env, int csrno, int ctr_idx = csrno - CSR_MCYCLE; PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; uint64_t mhpmctr_val = val; + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); counter->mhpmcounter_val = val; - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { - counter->mhpmcounter_prev = get_ticks(false); + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { + counter->mhpmcounter_prev = get_ticks(false, instr); if (ctr_idx > 2) { if (riscv_cpu_mxl(env) == MXL_RV32) { mhpmctr_val = mhpmctr_val | @@ -902,12 +906,12 @@ static RISCVException write_mhpmcounterh(CPURISCVState *env, int csrno, PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; uint64_t mhpmctr_val = counter->mhpmcounter_val; uint64_t mhpmctrh_val = val; + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); counter->mhpmcounterh_val = val; mhpmctr_val = mhpmctr_val | (mhpmctrh_val << 32); - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { - counter->mhpmcounterh_prev = get_ticks(true); + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { + counter->mhpmcounterh_prev = get_ticks(true, instr); if (ctr_idx > 2) { riscv_pmu_setup_timer(env, mhpmctr_val, ctr_idx); } @@ -926,6 +930,7 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, counter->mhpmcounter_prev; target_ulong ctr_val = upper_half ? counter->mhpmcounterh_val : counter->mhpmcounter_val; + bool instr = riscv_pmu_ctr_monitor_instructions(env, ctr_idx); if (get_field(env->mcountinhibit, BIT(ctr_idx))) { /* @@ -946,9 +951,8 @@ static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, * The kernel computes the perf delta by subtracting the current value from * the value it initialized previously (ctr_val). */ - if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || - riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { - *val = get_ticks(upper_half) - ctr_prev + ctr_val; + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || instr) { + *val = get_ticks(upper_half, instr) - ctr_prev + ctr_val; } else { *val = ctr_val; }
When icount is enabled, rather than returning the virtual CPU time, we should return the instruction count itself. Add an instructions bool parameter to get_ticks() to correctly return icount_get_raw() when icount_enabled() == 1 and instruction count is queried. This will modify the existing behavior which was returning an instructions count close to the number of cycles (CPI ~= 1). Signed-off-by: Clément Léger <cleger@rivosinc.com> --- v2: - Apply checkpatch and fixed missing braces --- target/riscv/csr.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)