Re: [PATCH 1/2] Btrfs: cleanup duplicated division functions
From: David Sterba <hidden>
Date: 2012-09-17 16:31:21
On Mon, Sep 17, 2012 at 10:21:00AM +0800, Miao Xie wrote:
On fri, 14 Sep 2012 15:54:18 +0200, David Sterba wrote:quoted
On Thu, Sep 13, 2012 at 06:51:36PM +0800, Miao Xie wrote:quoted
div_factor{_fine} has been implemented for two times, cleanup it. And I move them into a independent file named math.h because they are common math functions.You removed the sanity checks: - if (factor <= 0) - return 0; - if (factor >= 100) - return num;As inline functions, they should not contain complex checks, the caller should make sure the parameters are right. I think.
It's compiler's job to decide whether a function should be inlined or not. The keyword/function attribute 'inline' is only a hint, unless always_inline is used and the author should be sure that it really has the expected outcome and that compiler is wrong here. I don't agree that each caller should do the checks, it only makes code harder to read and forces the authors to check for conditions that may not be apparent or are just ommitted. If we need a function that does not check the boundaries, then of course go for it, but I don't see such case yet.
quoted
in new version. And I don't think it's necessary to add an extra include with a rather generic name and trivial code. A separate .h/.c with non-filesystem related support code like this looks more suitable. Do you intend to use the functions out of extent-tree.c ?They are used in both extent-tree.c and volumes.c from the outset, but they were implemented in these two files severally.
Ah, I see. david