On Sun, Sep 29, 2019 at 03:20:31PM +0800, jun.zh...@intel.com wrote:
> From: zhang jun <jun.zh...@intel.com>
>
> Documentation/x86/pat.txt says:
> set_memory_uc() or set_memory_wc() must use together with set_memory_wb()
I had to open that file to see what it actually says - btw, the filename
is pat.rst now - and you're very heavily paraphrasing what is there. So
try again explaining what the requirement is.
> if break the PAT attribute, there are tons of warning like:
> [ 45.846872] x86/PAT: NDK MediaCodec_:3753 map pfn RAM range req
That's some android NDK thing, it seems: "The Android NDK is a toolset
that lets you implement parts of your app in native code,... " lemme
guess, they have a kernel module?
> write-combining for [mem 0x1e7a80000-0x1e7a87fff], got write-back
> and in the extremely case, we see kernel panic unexpected like:
> list_del corruption. prev->next should be ffff88806dbe69c0,
> but was ffff888036f048c0
This is not really helpful. You need to explain what exactly you're
doing - not shortening the error messages.
> so it's better to priority the warn to error to highlight to
> remind the developer.
Whut?
>From reading what is trying hard to be a sentence, I can only guess what
you're trying to say here. And it doesn't make it clear why is pr_warn()
not enough and it has to be pr_err().
> Signed-off-by: zhang jun <jun.zh...@intel.com>
> Signed-off-by: he, bo <bo...@intel.com>
And this SOB chain is wrong.
> ---
> arch/x86/mm/pat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
> index d9fbd4f69920..43a4dfdcedc8 100644
> --- a/arch/x86/mm/pat.c
> +++ b/arch/x86/mm/pat.c
> @@ -897,7 +897,7 @@ static int reserve_pfn_range(u64 paddr, unsigned long
> size, pgprot_t *vma_prot,
>
> pcm = lookup_memtype(paddr);
> if (want_pcm != pcm) {
> - pr_warn("x86/PAT: %s:%d map pfn RAM range req %s for
> [mem %#010Lx-%#010Lx], got %s\n",
> + pr_err("x86/PAT: %s:%d map pfn RAM range req %s for
> [mem %#010Lx-%#010Lx], got %s!!!\n",
Three "!!!" would make this more urgent, huh?
How about you make the error message more informative and user-friendly,
instead?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
