Re: [kvm-unit-tests PATCH] lib/alloc_page: Revert to 'unsigned long' for @size params

From: Thomas Huth <thuth@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Andrew Jones <drjones@redhat.com>,
	Jim Mattson <jmattson@google.com>
Subject: Re: [kvm-unit-tests PATCH] lib/alloc_page: Revert to 'unsigned long' for @size params
Date: Tue, 14 Jul 2020 09:12:52 +0200	[thread overview]
Message-ID: <db6d8b2d-147b-d732-b638-b78a3fd980d2@redhat.com> (raw)
In-Reply-To: <20200714042046.13419-1-sean.j.christopherson@intel.com>

On 14/07/2020 06.20, Sean Christopherson wrote:
> Revert to using 'unsigned long' instead of 'size_t' for free_pages() and
> get_order().  The recent change to size_t for free_pages() breaks i386
> with -Werror as the assert_msg() formats expect unsigned longs, whereas
> size_t is an 'unsigned int' on i386 (though both longs and ints are 4
> bytes).
> 
> Message formatting aside, unsigned long is the correct choice given the
> current code base as alloc_pages() and free_pages_by_order() explicitly
> expect, work on, and/or assert on the size being an unsigned long.
> 
> Fixes: 73f4b202beb39 ("lib/alloc_page: change some parameter types")
> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Cc: Andrew Jones <drjones@redhat.com>
> Cc: Jim Mattson <jmattson@google.com>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
[...]
> diff --git a/lib/bitops.h b/lib/bitops.h
> index 308aa86..dd015e8 100644
> --- a/lib/bitops.h
> +++ b/lib/bitops.h
> @@ -79,7 +79,7 @@ static inline bool is_power_of_2(unsigned long n)
>  	return n && !(n & (n - 1));
>  }
>  
> -static inline unsigned int get_order(size_t size)
> +static inline unsigned int get_order(unsigned long size)
>  {
>  	return size ? fls(size) + !is_power_of_2(size) : 0;
>  }
> 

get_order() already used size_t when it was introduced in commit
f22e527df02ffaba ... is it necessary to switch it to unsigned long now?

Apart from that, this patch fixes the compilation problems, indeed, I
just checked it in the travis-CI.

Tested-by: Thomas Huth <thuth@redhat.com>