From: guoren@kernel.org
To: anup@brainfault.org, paul.walmsley@sifive.com,
palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de,
rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com,
bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com,
andy.chiu@sifive.com, e.shatokhin@yadro.com, guoren@kernel.org
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH -next V6 2/7] riscv: ftrace: Remove wasted nops for !RISCV_ISA_C
Date: Sat, 7 Jan 2023 08:35:44 -0500 [thread overview]
Message-ID: <20230107133549.4192639-3-guoren@kernel.org> (raw)
In-Reply-To: <20230107133549.4192639-1-guoren@kernel.org>
From: Guo Ren <guoren@linux.alibaba.com>
When CONFIG_RISCV_ISA_C=n, -fpatchable-function-entry=8 would generate
more nops than we expect. Because it treat nop opcode as 0x00000013
instead of 0x0001.
Dump of assembler code for function dw_pcie_free_msi:
0xffffffff806fce94 <+0>: sd ra,-8(sp)
0xffffffff806fce98 <+4>: auipc ra,0xff90f
0xffffffff806fce9c <+8>: jalr -684(ra) # 0xffffffff8000bbec
<ftrace_caller>
0xffffffff806fcea0 <+12>: ld ra,-8(sp)
0xffffffff806fcea4 <+16>: nop /* wasted */
0xffffffff806fcea8 <+20>: nop /* wasted */
0xffffffff806fceac <+24>: nop /* wasted */
0xffffffff806fceb0 <+28>: nop /* wasted */
0xffffffff806fceb4 <+0>: addi sp,sp,-48
0xffffffff806fceb8 <+4>: sd s0,32(sp)
0xffffffff806fcebc <+8>: sd s1,24(sp)
0xffffffff806fcec0 <+12>: sd s2,16(sp)
0xffffffff806fcec4 <+16>: sd s3,8(sp)
0xffffffff806fcec8 <+20>: sd ra,40(sp)
0xffffffff806fcecc <+24>: addi s0,sp,48
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 12d91b0a73d8..ea5a91da6897 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -11,7 +11,11 @@ LDFLAGS_vmlinux :=
ifeq ($(CONFIG_DYNAMIC_FTRACE),y)
LDFLAGS_vmlinux := --no-relax
KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
+ifeq ($(CONFIG_RISCV_ISA_C),y)
CC_FLAGS_FTRACE := -fpatchable-function-entry=8
+else
+ CC_FLAGS_FTRACE := -fpatchable-function-entry=4
+endif
endif
ifeq ($(CONFIG_CMODEL_MEDLOW),y)
--
2.36.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2023-01-07 13:36 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-07 13:35 [PATCH -next V6 0/7] riscv: Optimize function trace guoren
2023-01-07 13:35 ` [PATCH -next V6 1/7] riscv: ftrace: Fixup panic by disabling preemption guoren
2023-01-09 17:19 ` Mark Rutland
2023-01-11 13:22 ` Guo Ren
2023-01-12 12:05 ` Mark Rutland
2023-01-28 10:00 ` Guo Ren
2023-01-29 5:36 ` Guo Ren
2023-01-30 11:17 ` Mark Rutland
2023-02-07 2:31 ` Guo Ren
2023-01-07 13:35 ` guoren [this message]
2023-01-07 13:35 ` [PATCH -next V6 3/7] riscv: ftrace: Reduce the detour code size to half guoren
2023-01-10 17:13 ` Evgenii Shatokhin
2023-01-11 9:58 ` Guo Ren
2023-01-07 13:35 ` [PATCH -next V6 4/7] riscv: ftrace: Add ftrace_graph_func guoren
2023-01-07 13:35 ` [PATCH -next V6 5/7] riscv: ftrace: Make ftrace_caller call ftrace_graph_func guoren
2023-01-10 17:16 ` Evgenii Shatokhin
2023-01-11 8:23 ` Guo Ren
2023-01-11 8:41 ` Guo Ren
2023-01-07 13:35 ` [PATCH -next V6 6/7] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support guoren
2023-01-07 13:35 ` [PATCH -next V6 7/7] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] guoren
2023-01-10 13:08 ` Evgenii Shatokhin
2023-01-10 13:50 ` Evgenii Shatokhin
2023-01-11 9:50 ` Song Shuai
2023-01-11 9:59 ` Guo Ren
2023-01-13 10:48 ` Song Shuai
2023-01-17 3:20 ` Guo Ren
2023-01-11 10:11 ` [PATCH -next V6 0/7] riscv: Optimize function trace Song Shuai
2023-01-11 14:03 ` Guo Ren
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230107133549.4192639-3-guoren@kernel.org \
--to=guoren@kernel.org \
--cc=andy.chiu@sifive.com \
--cc=anup@brainfault.org \
--cc=bp@suse.de \
--cc=conor.dooley@microchip.com \
--cc=e.shatokhin@yadro.com \
--cc=guoren@linux.alibaba.com \
--cc=heiko@sntech.de \
--cc=jolsa@redhat.com \
--cc=jpoimboe@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=mhiramat@kernel.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=rostedt@goodmis.org \
--cc=suagrfillet@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox