On Thu, 2018-04-12 at 08:22 +0200, Julia Lawall wrote: > On Wed, 11 Apr 2018, Joe Perches wrote: > > On Wed, 2018-04-11 at 09:29 -0700, Andrew Morton wrote: > > > We already have some 500 bools-in-structs > > > > I got at least triple that only in include/ > > so I expect there are at probably an order > > of magnitude more than 500 in the kernel. > > > > I suppose some cocci script could count the > > actual number of instances. A regex can not. > > I got 12667.
Could you please post the cocci script? > I'm not sure to understand the issue. Will using a bitfield help if there > are no other bitfields in the structure? IMO, not really. The primary issue is described by Linus here: https://lkml.org/lkml/2017/11/21/384 I personally do not find a significant issue with uncontrolled sizes of bool in kernel structs as all of the kernel structs are transitory and not written out to storage. I suppose bool bitfields are also OK, but for the RMW required. Using unsigned int :1 bitfield instead of bool :1 has the negative of truncation so that the uint has to be set with !! instead of a simple assign.