lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 13 Feb 2019 15:56:46 +0100 From: Frederic Weisbecker <frederic@...nel.org> To: Linus Torvalds <torvalds@...ux-foundation.org> Cc: LKML <linux-kernel@...r.kernel.org>, Sebastian Andrzej Siewior <bigeasy@...utronix.de>, Peter Zijlstra <peterz@...radead.org>, Mauro Carvalho Chehab <mchehab@...pensource.com>, "David S . Miller" <davem@...emloft.net>, Thomas Gleixner <tglx@...utronix.de>, "Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>, Frederic Weisbecker <fweisbec@...il.com>, Pavan Kondeti <pkondeti@...eaurora.org>, Ingo Molnar <mingo@...nel.org>, Joel Fernandes <joel@...lfernandes.org> Subject: Re: [PATCH 02/32] locking/lockdep: Introduce struct lock_usage On Tue, Feb 12, 2019 at 09:38:42AM -0800, Linus Torvalds wrote: > On Tue, Feb 12, 2019 at 9:14 AM Frederic Weisbecker <frederic@...nel.org> wrote: > > > > +static u64 lock_usage_mask(struct lock_usage *usage) > > +{ > > + return BIT(usage->bit); > > +} > > More insane "u64" - and it's *incorrect* too. > > #define BIT(nr) (1UL << (nr)) > > fundamentally means that "BIT()" can only work on up to "unsigned long". > > So this odd use of u64 seems to be a disease. It only uses more memory > (and more CPU) for no obvious reason. > > u64 is not some "default type". It's expensive and shouldn't be used > unless you have a *reason* for it. Right, I'll simply move "[PATCH 03/32] locking/lockdep: Convert usage_mask to u64" at the first position and follow up on that to justify its use. Thanks.
Powered by blists - more mailing lists