On Thu, 25 Apr 2019, Li, Aubrey wrote:
On 2019/4/25 5:18, Thomas Gleixner wrote:
quoted
On Mon, 22 Apr 2019, Aubrey Li wrote:
quoted
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5ad92419be19..d5a9c5ddd453 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -208,6 +208,7 @@ config X86
select USER_STACKTRACE_SUPPORT
select VIRT_TO_BUS
select X86_FEATURE_NAMES if PROC_FS
+ select PROC_PID_ARCH_STATUS if PROC_FS
Can you please stop mixing arch and proc code? There is no point in
enabling this on x86 right away.
quoted
+
+config PROC_PID_ARCH_STATUS
+ bool "Enable /proc/<pid>/arch_status file"
Why is this switchable? x86 selects it if PROC_FS is enabled and all other
architectures are absolutely not interested in this.
Above and this, I was trying to avoid an empty arch_file on other architectures.
In previous proposal the entry only exists on the platform with AVX512.
What's the benefit of having a conditional enabled empty file for all other
architectures? Nothing AFAICT.
quoted
quoted
+/*
+ * Add support for task architecture specific output in /proc/pid/arch_status.
+ * task_arch_status() must be defined in asm/processor.h
+ */
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+# ifndef task_arch_status
+# define task_arch_status(m, task)
+# endif
What exactly is the point of this macro mess? If an architecture selects
CONFIG_PROC_PID_ARCH_STATUS then it has to provide proc_task_arch_status()
and the prototype should be in include/linux/proc_fs.h.
I was trying to address Andy's last comments. If we have the prototype in
include/linux/proc_fs.h, we'll have a weak function definition in fs/proc/array.c,
which bloats other architectures.
In that way proc_task_arch_status() should be defined in asm/processor.h,
but proc_task_arch_status() has four parameters, I don't want unnecessary
"struct pid_namespace *ns" and "struct pid *pid" leaked into arch headers,
so I defined task_arch_status(m, task) to avoid that.
This #define mess is ugly and pointless. Let the arch select
CONFIG_PROC_PID_ARCH_STATUS and if it selects it it has to provide the
function. No waek function required at all.
Thanks,
tglx