[Xen-devel] [PATCH 03/27] xen/x86: mm: Don't check alloc_boot_pages return

[Julien Grall <julien.grall@xxxxxxx>]

The only way alloc_boot_pages will return 0 is during the error case.
Although, Xen will panic in the error path. So the check in the caller
is pointless.

Looking at the loop, my understanding is it will try to allocate in
smaller chunk if a bigger chunk fail. Given that alloc_boot_pages can
never check, the loop seems unecessary.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---

Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

I haven't tested this code, only build test it. I can't see how
alloc_boot_pages would return 0 other than the error path.
---
 xen/arch/x86/mm.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index f53ca43554..66e337109d 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -200,11 +200,7 @@ static void __init init_frametable_chunk(void *start, void 
*end)
          */
         while ( step && s + (step << PAGE_SHIFT) > e + (4 << PAGE_SHIFT) )
             step >>= PAGETABLE_ORDER;
-        do {
-            mfn = alloc_boot_pages(step, step);
-        } while ( !mfn && (step >>= PAGETABLE_ORDER) );
-        if ( !mfn )
-            panic("Not enough memory for frame table");
+        mfn = alloc_boot_pages(step, step);
         map_pages_to_xen(s, mfn, step, PAGE_HYPERVISOR);
     }
 
-- 
2.11.0


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