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, 11 Sep 2013 19:52:48 +0100 From: Al Viro <viro@...IV.linux.org.uk> To: "J. Bruce Fields" <bfields@...ldses.org> Cc: Waiman Long <waiman.long@...com>, Thomas Gleixner <tglx@...utronix.de>, Linus Torvalds <torvalds@...ux-foundation.org>, linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, "Chandramouleeswaran, Aswin" <aswin@...com>, "Norton, Scott J" <scott.norton@...com> Subject: Re: [PATCH 1/2] seqlock: Add a new blocking reader type On Wed, Sep 11, 2013 at 02:40:38PM -0400, J. Bruce Fields wrote: > On Wed, Sep 11, 2013 at 06:26:25PM +0100, Al Viro wrote: > > On Wed, Sep 11, 2013 at 12:33:35PM -0400, Waiman Long wrote: > > > > > >Folks, any suggestions on better names? The semantics we are getting is > > > > > > I will welcome any better name suggestion and will incorporate that > > > in the patch. > > > > FWIW, the suggestions I've seen so far had been > > > > seq_exreadlock() [ex for exclusive] > > seq_exclreadlock() [ditto, and IMO fails the "easily read over the phone" > > test - /sekv-excre...ARRGH/] > > seq_prot_readlock() [prot for protected, as in DLM protected read] > > Though the DLM protected read doesn't self-conflict either so that's a > poor analogy, my bad. > > (Do the users really require that the read be exclusive?) We want to exclude writers and since the writer is lock: spin_lock(&sl->lock), bump sl->sequence by 1, smp_wmb() unlock: smp_wmb(), bump sl->sequence by 1, spin_unlock(&sl->lock) the obvious implementation for this new primitive is simply spin_{lock,unlock} on the same spinlock... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists