Re: [PATCH v1 2/4] powerpc/mm: print warning in arch_remove_linear_mapping()
flat view
From: osalvador <osalvador@suse.de>
Date: 2020-11-04 09:43:08
Also in:
linux-mm, lkml
On Thu, Oct 29, 2020 at 05:27:16PM +0100, David Hildenbrand wrote:
quoted hunk ↗ jump to hunk
Let's print a warning similar to in arch_add_linear_mapping() instead of WARN_ON_ONCE() and eventually crashing the kernel. Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Rashmica Gupta <redacted> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <redacted> Signed-off-by: David Hildenbrand <redacted> --- arch/powerpc/mm/mem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 8a86d81f8df0..685028451dd2 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c@@ -145,7 +145,9 @@ void __ref arch_remove_linear_mapping(u64 start, u64 size) flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE); ret = remove_section_mapping(start, start + size); - WARN_ON_ONCE(ret); + if (ret) + pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n", + start, start + size, ret);
I guess the fear is to panic on systems that do have panic_on_warn (not sure how many productions systems have this out there). But anyway, being coherent with that, I think you should remove the WARN_ON in hash__remove_section_mapping as well. Besides that: Reviewed-by: Oscar Salvador <<redacted> Not sure if the functions below that also have any sort of WARN_ON. native_hpte_removebolted has a VM_WARN_ON, but that is on CONFIG_DEBUG_VM so does not really matter. -- Oscar Salvador SUSE L3