Re: [QUESTION] support perf record --call-graph dwarf for mips
From: Tiezhu Yang
Date: Thu Dec 17 2020 - 07:49:47 EST
On 12/16/2020 11:16 PM, Arnaldo Carvalho de Melo wrote:
Em Wed, Dec 16, 2020 at 11:30:47AM -0300, Arnaldo Carvalho de Melo escreveu:
Em Wed, Dec 16, 2020 at 07:14:02PM +0800, Jiaxun Yang escreveu:
在 2020/12/16 下午6:05, Tiezhu Yang 写道:
Hi,
In the current upstream mainline kernel, perf record --call-graph dwarf
is not supported for architecture mips64. I find the following related
patches about this feature by David Daney <david.daney@xxxxxxxxxx> and
Archer Yan <ayan@xxxxxxxxxxxx> in Sep 2019.
AFAIK ddaney left Cavium at 2018 and Wave Computing Shanghai is defuncted...
Feel free to take over if you like, there is no licenses issue, just
remember to credit
others properly.
Ralf, can you take a look at the kernel part? The user space part seems
ok.
I take that back, but made some progress in getting that old patch
closer to what we have now in tools/perf/, see below.
Someone with a mips system should try to refresh the kernel bits and
then see if the patch below works.
- Arnaldo
commit e59de40addb092d7167fa1dd7c6640d0fab41ede
Author: David Daney <david.daney@xxxxxxxxxx>
Date: Wed Sep 11 08:26:37 2019 +0000
perf mips: Support mips unwinding and dwarf-regs.
Map perf APIs(perf_reg_name/get_arch_regstr/unwind__arch_reg_id)
with MIPS specific registers.
[ayan@xxxxxxxxxxxx: repick this patch for unwinding userstack
backtrace by perf and libunwind on MIPS based CPU.]
Committer notes:
Some header fixups, replace CONFIG_LIBUNWIND with CONFIG_LOCAL_LIBUNWIND
to cope with:
9d8e14d306ef2f5d ("perf unwind: Separate local/remote libunwind config")
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20190911082548.31546-1-ayan@xxxxxxxxxxxx
Signed-off-by: Archer Yan <ayan@xxxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
diff --git a/tools/perf/arch/mips/Makefile b/tools/perf/arch/mips/Makefile
new file mode 100644
index 0000000000000000..6e1106fab26e4015
--- /dev/null
+++ b/tools/perf/arch/mips/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+endif
diff --git a/tools/perf/arch/mips/include/perf_regs.h b/tools/perf/arch/mips/include/perf_regs.h
new file mode 100644
index 0000000000000000..36a28bc1734787ce
--- /dev/null
+++ b/tools/perf/arch/mips/include/perf_regs.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_PERF_REGS_H
+#define ARCH_PERF_REGS_H
+
+#include <stdlib.h>
+#include <linux/types.h>
+#include <asm/perf_regs.h>
+
+#define PERF_REG_IP PERF_REG_MIPS_PC
+#define PERF_REG_SP PERF_REG_MIPS_R29
+
+#define PERF_REGS_MASK ((1ULL << PERF_REG_MIPS_MAX) - 1)
+
+static inline const char *perf_reg_name(int id)
+{
+ switch (id) {
+ case PERF_REG_MIPS_PC:
+ return "PC";
+ case PERF_REG_MIPS_R1:
+ return "$1";
+ case PERF_REG_MIPS_R2:
+ return "$2";
+ case PERF_REG_MIPS_R3:
+ return "$3";
+ case PERF_REG_MIPS_R4:
+ return "$4";
+ case PERF_REG_MIPS_R5:
+ return "$5";
+ case PERF_REG_MIPS_R6:
+ return "$6";
+ case PERF_REG_MIPS_R7:
+ return "$7";
+ case PERF_REG_MIPS_R8:
+ return "$8";
+ case PERF_REG_MIPS_R9:
+ return "$9";
+ case PERF_REG_MIPS_R10:
+ return "$10";
+ case PERF_REG_MIPS_R11:
+ return "$11";
+ case PERF_REG_MIPS_R12:
+ return "$12";
+ case PERF_REG_MIPS_R13:
+ return "$13";
+ case PERF_REG_MIPS_R14:
+ return "$14";
+ case PERF_REG_MIPS_R15:
+ return "$15";
+ case PERF_REG_MIPS_R16:
+ return "$16";
+ case PERF_REG_MIPS_R17:
+ return "$17";
+ case PERF_REG_MIPS_R18:
+ return "$18";
+ case PERF_REG_MIPS_R19:
+ return "$19";
+ case PERF_REG_MIPS_R20:
+ return "$20";
+ case PERF_REG_MIPS_R21:
+ return "$21";
+ case PERF_REG_MIPS_R22:
+ return "$22";
+ case PERF_REG_MIPS_R23:
+ return "$23";
+ case PERF_REG_MIPS_R24:
+ return "$24";
+ case PERF_REG_MIPS_R25:
+ return "$25";
+ case PERF_REG_MIPS_R28:
+ return "$28";
+ case PERF_REG_MIPS_R29:
+ return "$29";
+ case PERF_REG_MIPS_R30:
+ return "$30";
+ case PERF_REG_MIPS_R31:
+ return "$31";
+ default:
+ break;
+ }
+ return NULL;
+}
+
+#endif /* ARCH_PERF_REGS_H */
diff --git a/tools/perf/arch/mips/util/Build b/tools/perf/arch/mips/util/Build
new file mode 100644
index 0000000000000000..7b0c0457154a22c5
--- /dev/null
+++ b/tools/perf/arch/mips/util/Build
@@ -0,0 +1,2 @@
+perf-$(CONFIG_DWARF) += dwarf-regs.o
+perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
diff --git a/tools/perf/arch/mips/util/dwarf-regs.c b/tools/perf/arch/mips/util/dwarf-regs.c
new file mode 100644
index 0000000000000000..165e0179ea11d9b2
--- /dev/null
+++ b/tools/perf/arch/mips/util/dwarf-regs.c
@@ -0,0 +1,37 @@
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+static const char *mips_gpr_names[32] = {
+ "$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8", "$9",
+ "$10", "$11", "$12", "$13", "$14", "$15", "$16", "$17", "$18", "$19",
+ "$20", "$21", "$22", "$23", "$24", "$25", "$26", "$27", "$28", "$29",
+ "$30", "$31"
+};
+
+const char *get_arch_regstr(unsigned int n)
+{
+ if (n < 32)
+ return mips_gpr_names[n];
+ if (n == 64)
+ return "hi";
+ if (n == 65)
+ return "lo";
+ return NULL;
+}
diff --git a/tools/perf/arch/mips/util/unwind-libunwind.c b/tools/perf/arch/mips/util/unwind-libunwind.c
new file mode 100644
index 0000000000000000..7af25427943f451a
--- /dev/null
+++ b/tools/perf/arch/mips/util/unwind-libunwind.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <libunwind.h>
+#include "perf_regs.h"
+#include "../../util/unwind.h"
+
+int unwind__arch_reg_id(int regnum)
+{
+ switch (regnum) {
+ case UNW_MIPS_R1 ... UNW_MIPS_R25:
+ return regnum - UNW_MIPS_R1 + PERF_REG_MIPS_R1;
+ case UNW_MIPS_R28 ... UNW_MIPS_R31:
+ return regnum - UNW_MIPS_R28 + PERF_REG_MIPS_R28;
+ case UNW_MIPS_PC:
+ return PERF_REG_MIPS_PC;
+ default:
+ pr_err("unwind: invalid reg id %d\n", regnum);
+ return -EINVAL;
+ }
+}
(1)There exists build errors used with the above patch:
LINK perf
perf-in.o: In function `get_dwarf_regstr':
/home/loongson/linux-5.10-rc7/tools/perf/util/dwarf-regs.c:33: undefined
reference to `get_arch_regstr'
/home/loongson/linux-5.10-rc7/tools/perf/util/dwarf-regs.c:35: undefined
reference to `get_arch_regstr'
collect2: error: ld returned 1 exit status
Makefile.perf:659: recipe for target 'perf' failed
make[2]: *** [perf] Error 1
Makefile.perf:232: recipe for target 'sub-make' failed
make[1]: *** [sub-make] Error 2
Makefile:69: recipe for target 'all' failed
make: *** [all] Error 2
(2)We need to modify tools/perf/arch/mips/Build, then build successful.
diff --git a/tools/perf/arch/mips/Build b/tools/perf/arch/mips/Build
index 1bb8bf6d7fd4..54afe4a467e7 100644
--- a/tools/perf/arch/mips/Build
+++ b/tools/perf/arch/mips/Build
@@ -1 +1 @@
-# empty
+libperf-y += util/
(3)[loongson@linux perf]$ ./perf record --call-graph dwarf cd
Error:
The sys_perf_event_open() syscall returned with 89 (Function not
implemented) for event (cycles:u).
/bin/dmesg | grep -i perf may provide additional information.
Call Trace:
record__open
evsel__open()
evsel__open_cpu()
perf_event_open()
evsel__open_strerror
Maybe we need tools/perf/arch/mips/entry/syscalls/syscall.tbl?