| Message ID | 20240701043430.66666-16-atrajeev@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | Add data type profiling support for powerpc | expand |
On Mon, Jul 01, 2024 at 10:04:28AM +0530, Athira Rajeev wrote: > There are cases where define a global register variable and associate it > with a specified register. Example, in powerpc, two registers are > defined to represent variable: > 1. r13: represents local_paca > register struct paca_struct *local_paca asm("r13"); > > 2. r1: represents stack_pointer > register void *__stack_pointer asm("r1"); > > These regs are present in dwarf debug as DW_OP_reg as part of variables > in the cu_die (compile unit). These are not present in die search done > in the list of nested scopes since these are global register variables. > > Example for local_paca represented by r13: > > <<>> > <1><18dc6b4>: Abbrev Number: 128 (DW_TAG_variable) > <18dc6b6> DW_AT_name : (indirect string, offset: 0x3861): local_paca > <18dc6ba> DW_AT_decl_file : 48 > <18dc6bb> DW_AT_decl_line : 36 > <18dc6bc> DW_AT_decl_column : 30 > <18dc6bd> DW_AT_type : <0x18dc6c3> > <18dc6c1> DW_AT_external : 1 > <18dc6c1> DW_AT_location : 1 byte block: 5d (DW_OP_reg13 (r13)) > > <1><18dc6c3>: Abbrev Number: 3 (DW_TAG_pointer_type) > <18dc6c4> DW_AT_byte_size : 8 > <18dc6c4> DW_AT_type : <0x18dc353> > > Where DW_AT_type : <0x18dc6c3> further points to : > > <1><18dc6c3>: Abbrev Number: 3 (DW_TAG_pointer_type) > <18dc6c4> DW_AT_byte_size : 8 > <18dc6c4> DW_AT_type : <0x18dc353> > > which belongs to: > > <1><18dc353>: Abbrev Number: 67 (DW_TAG_structure_type) > <18dc354> DW_AT_name : (indirect string, offset: 0x56cd): paca_struct > <18dc358> DW_AT_byte_size : 2944 > <18dc35a> DW_AT_alignment : 128 > <18dc35b> DW_AT_decl_file : 48 > <18dc35c> DW_AT_decl_line : 61 > <18dc35d> DW_AT_decl_column : 8 > <18dc35d> DW_AT_sibling : <0x18dc6b4> > <<>> > > Similar is case with "r1". > > <<>> > <1><18dd772>: Abbrev Number: 129 (DW_TAG_variable) > <18dd774> DW_AT_name : (indirect string, offset: 0x11ba): current_stack_pointer > <18dd778> DW_AT_decl_file : 51 > <18dd779> DW_AT_decl_line : 1468 > <18dd77b> DW_AT_decl_column : 24 > <18dd77c> DW_AT_type : <0x18da5cd> > <18dd780> DW_AT_external : 1 > <18dd780> DW_AT_location : 1 byte block: 51 (DW_OP_reg1 (r1)) > > where 18da5cd is: > > <1><18da5cd>: Abbrev Number: 47 (DW_TAG_base_type) > <18da5ce> DW_AT_byte_size : 8 > <18da5cf> DW_AT_encoding : 7 (unsigned) > <18da5d0> DW_AT_name : (indirect string, offset: 0x55c7): long unsigned int > <<>> > > To identify data type for these two special cases, iterate over > variables in the CU die (Compile Unit) and match it with the register. > If the variable is a base type, ie die_get_real_type will return NULL > here, set offset to zero. With the changes, data type for "paca_struct" > and "long unsigned int" for r1 is identified. > > Snippet from ./perf report -s type,type_off > > 12.85% long unsigned int long unsigned int +0 (no field) > 4.68% struct paca_struct struct paca_struct +2312 (__current) > 4.57% struct paca_struct struct paca_struct +2354 (irq_soft_mask) > > Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> > --- > tools/perf/util/annotate-data.c | 42 ++++++++++++++++++++++++++++ > tools/perf/util/annotate.c | 8 ++++++ > tools/perf/util/annotate.h | 1 + > tools/perf/util/include/dwarf-regs.h | 1 + > 4 files changed, 52 insertions(+) > > diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c > index 721235e1e6cf..c919b2259f54 100644 > --- a/tools/perf/util/annotate-data.c > +++ b/tools/perf/util/annotate-data.c > @@ -1175,6 +1175,42 @@ static int find_data_type_block(struct data_loc_info *dloc, > return ret; > } > > +/* > + * Handle cases where define a global register variable and > + * associate it with a specified register. These regs are > + * present in dwarf debug as DW_OP_reg as part of variables > + * in the cu_die (compile unit). Iterate over variables in the > + * cu_die and match with reg to identify data type die. > + */ > +static int find_data_type_global_reg(struct data_loc_info *dloc, int reg, Dwarf_Die *cu_die, > + Dwarf_Die *type_die) > +{ > + Dwarf_Die vr_die; > + int ret = -1; > + struct die_var_type *var_types = NULL; > + > + die_collect_vars(cu_die, &var_types); > + while (var_types) { > + if (var_types->reg == reg) { Reduce the indent level by using for and continue. Like for (vt = var_types ; vt != NULL; vt = vt->next) { if (vt->reg != reg) continue; ... } > + if (dwarf_offdie(dloc->di->dbg, var_types->die_off, &vr_die)) { > + if (die_get_real_type(&vr_die, type_die) == NULL) { > + dloc->type_offset = 0; > + dwarf_offdie(dloc->di->dbg, var_types->die_off, type_die); > + } > + pr_debug_type_name(type_die, TSR_KIND_TYPE); > + ret = 0; > + pr_debug_dtp("found by CU for %s (die:%#lx)\n", > + dwarf_diename(type_die), (long)dwarf_dieoffset(type_die)); > + } > + break; > + } > + var_types = var_types->next; > + } > + > + delete_var_types(var_types); You should remember the start of var_types to free them properly. Thanks, Namhyung > + return ret; > +} > + > /* The result will be saved in @type_die */ > static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) > { > @@ -1222,6 +1258,12 @@ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) > pr_debug_dtp("CU for %s (die:%#lx)\n", > dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die)); > > + if (loc->reg_type == DWARF_REG_GLOBAL) { > + ret = find_data_type_global_reg(dloc, reg, &cu_die, type_die); > + if (!ret) > + goto out; > + } > + > if (reg == DWARF_REG_PC) { > if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr, > &offset, type_die)) { > diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c > index ce99db291c5e..8db2f32700aa 100644 > --- a/tools/perf/util/annotate.c > +++ b/tools/perf/util/annotate.c > @@ -2425,6 +2425,14 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he) > op_loc->reg1 = DWARF_REG_PC; > } > > + /* Global reg variable 13 and 1 > + * assign to DWARF_REG_GLOBAL > + */ > + if (arch__is(arch, "powerpc")) { > + if ((op_loc->reg1 == 13) || (op_loc->reg1 == 1)) > + op_loc->reg_type = DWARF_REG_GLOBAL; > + } > + > mem_type = find_data_type(&dloc); > > if (mem_type == NULL && is_stack_canary(arch, op_loc)) { > diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h > index 9ba772f46270..ad69842a8ebc 100644 > --- a/tools/perf/util/annotate.h > +++ b/tools/perf/util/annotate.h > @@ -475,6 +475,7 @@ struct annotated_op_loc { > bool mem_ref; > bool multi_regs; > bool imm; > + int reg_type; > }; > > enum annotated_insn_ops { > diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h > index 8fb987818b1a..fda7098c13e1 100644 > --- a/tools/perf/util/include/dwarf-regs.h > +++ b/tools/perf/util/include/dwarf-regs.h > @@ -5,6 +5,7 @@ > > #define DWARF_REG_PC 0xd3af9c /* random number */ > #define DWARF_REG_FB 0xd3affb /* random number */ > +#define DWARF_REG_GLOBAL 0xd3affc /* random number */ > > #ifdef HAVE_DWARF_SUPPORT > const char *get_arch_regstr(unsigned int n); > -- > 2.43.0 >
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c index 721235e1e6cf..c919b2259f54 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -1175,6 +1175,42 @@ static int find_data_type_block(struct data_loc_info *dloc, return ret; } +/* + * Handle cases where define a global register variable and + * associate it with a specified register. These regs are + * present in dwarf debug as DW_OP_reg as part of variables + * in the cu_die (compile unit). Iterate over variables in the + * cu_die and match with reg to identify data type die. + */ +static int find_data_type_global_reg(struct data_loc_info *dloc, int reg, Dwarf_Die *cu_die, + Dwarf_Die *type_die) +{ + Dwarf_Die vr_die; + int ret = -1; + struct die_var_type *var_types = NULL; + + die_collect_vars(cu_die, &var_types); + while (var_types) { + if (var_types->reg == reg) { + if (dwarf_offdie(dloc->di->dbg, var_types->die_off, &vr_die)) { + if (die_get_real_type(&vr_die, type_die) == NULL) { + dloc->type_offset = 0; + dwarf_offdie(dloc->di->dbg, var_types->die_off, type_die); + } + pr_debug_type_name(type_die, TSR_KIND_TYPE); + ret = 0; + pr_debug_dtp("found by CU for %s (die:%#lx)\n", + dwarf_diename(type_die), (long)dwarf_dieoffset(type_die)); + } + break; + } + var_types = var_types->next; + } + + delete_var_types(var_types); + return ret; +} + /* The result will be saved in @type_die */ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) { @@ -1222,6 +1258,12 @@ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) pr_debug_dtp("CU for %s (die:%#lx)\n", dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die)); + if (loc->reg_type == DWARF_REG_GLOBAL) { + ret = find_data_type_global_reg(dloc, reg, &cu_die, type_die); + if (!ret) + goto out; + } + if (reg == DWARF_REG_PC) { if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr, &offset, type_die)) { diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index ce99db291c5e..8db2f32700aa 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -2425,6 +2425,14 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he) op_loc->reg1 = DWARF_REG_PC; } + /* Global reg variable 13 and 1 + * assign to DWARF_REG_GLOBAL + */ + if (arch__is(arch, "powerpc")) { + if ((op_loc->reg1 == 13) || (op_loc->reg1 == 1)) + op_loc->reg_type = DWARF_REG_GLOBAL; + } + mem_type = find_data_type(&dloc); if (mem_type == NULL && is_stack_canary(arch, op_loc)) { diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h index 9ba772f46270..ad69842a8ebc 100644 --- a/tools/perf/util/annotate.h +++ b/tools/perf/util/annotate.h @@ -475,6 +475,7 @@ struct annotated_op_loc { bool mem_ref; bool multi_regs; bool imm; + int reg_type; }; enum annotated_insn_ops { diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h index 8fb987818b1a..fda7098c13e1 100644 --- a/tools/perf/util/include/dwarf-regs.h +++ b/tools/perf/util/include/dwarf-regs.h @@ -5,6 +5,7 @@ #define DWARF_REG_PC 0xd3af9c /* random number */ #define DWARF_REG_FB 0xd3affb /* random number */ +#define DWARF_REG_GLOBAL 0xd3affc /* random number */ #ifdef HAVE_DWARF_SUPPORT const char *get_arch_regstr(unsigned int n);
There are cases where define a global register variable and associate it with a specified register. Example, in powerpc, two registers are defined to represent variable: 1. r13: represents local_paca register struct paca_struct *local_paca asm("r13"); 2. r1: represents stack_pointer register void *__stack_pointer asm("r1"); These regs are present in dwarf debug as DW_OP_reg as part of variables in the cu_die (compile unit). These are not present in die search done in the list of nested scopes since these are global register variables. Example for local_paca represented by r13: <<>> <1><18dc6b4>: Abbrev Number: 128 (DW_TAG_variable) <18dc6b6> DW_AT_name : (indirect string, offset: 0x3861): local_paca <18dc6ba> DW_AT_decl_file : 48 <18dc6bb> DW_AT_decl_line : 36 <18dc6bc> DW_AT_decl_column : 30 <18dc6bd> DW_AT_type : <0x18dc6c3> <18dc6c1> DW_AT_external : 1 <18dc6c1> DW_AT_location : 1 byte block: 5d (DW_OP_reg13 (r13)) <1><18dc6c3>: Abbrev Number: 3 (DW_TAG_pointer_type) <18dc6c4> DW_AT_byte_size : 8 <18dc6c4> DW_AT_type : <0x18dc353> Where DW_AT_type : <0x18dc6c3> further points to : <1><18dc6c3>: Abbrev Number: 3 (DW_TAG_pointer_type) <18dc6c4> DW_AT_byte_size : 8 <18dc6c4> DW_AT_type : <0x18dc353> which belongs to: <1><18dc353>: Abbrev Number: 67 (DW_TAG_structure_type) <18dc354> DW_AT_name : (indirect string, offset: 0x56cd): paca_struct <18dc358> DW_AT_byte_size : 2944 <18dc35a> DW_AT_alignment : 128 <18dc35b> DW_AT_decl_file : 48 <18dc35c> DW_AT_decl_line : 61 <18dc35d> DW_AT_decl_column : 8 <18dc35d> DW_AT_sibling : <0x18dc6b4> <<>> Similar is case with "r1". <<>> <1><18dd772>: Abbrev Number: 129 (DW_TAG_variable) <18dd774> DW_AT_name : (indirect string, offset: 0x11ba): current_stack_pointer <18dd778> DW_AT_decl_file : 51 <18dd779> DW_AT_decl_line : 1468 <18dd77b> DW_AT_decl_column : 24 <18dd77c> DW_AT_type : <0x18da5cd> <18dd780> DW_AT_external : 1 <18dd780> DW_AT_location : 1 byte block: 51 (DW_OP_reg1 (r1)) where 18da5cd is: <1><18da5cd>: Abbrev Number: 47 (DW_TAG_base_type) <18da5ce> DW_AT_byte_size : 8 <18da5cf> DW_AT_encoding : 7 (unsigned) <18da5d0> DW_AT_name : (indirect string, offset: 0x55c7): long unsigned int <<>> To identify data type for these two special cases, iterate over variables in the CU die (Compile Unit) and match it with the register. If the variable is a base type, ie die_get_real_type will return NULL here, set offset to zero. With the changes, data type for "paca_struct" and "long unsigned int" for r1 is identified. Snippet from ./perf report -s type,type_off 12.85% long unsigned int long unsigned int +0 (no field) 4.68% struct paca_struct struct paca_struct +2312 (__current) 4.57% struct paca_struct struct paca_struct +2354 (irq_soft_mask) Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> --- tools/perf/util/annotate-data.c | 42 ++++++++++++++++++++++++++++ tools/perf/util/annotate.c | 8 ++++++ tools/perf/util/annotate.h | 1 + tools/perf/util/include/dwarf-regs.h | 1 + 4 files changed, 52 insertions(+)