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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sat, 10 Aug 2019 18:22:20 -0700
From:   Matthew Wilcox <>
To:     Christoph Hellwig <>
Cc:     Thomas Gleixner <>,
        LKML <>,
        Peter Zijlstra <>,
        Ingo Molnar <>,
        Sebastian Siewior <>,
        Anna-Maria Gleixner <>,
        Steven Rostedt <>,
        Julia Cartwright <>, Jan Kara <>,
        Theodore Tso <>,
        Alexander Viro <>,,,
        Jan Kara <>, Mark Fasheh <>,
        Joseph Qi <>,
        Joel Becker <>
Subject: Re: [patch V2 0/7] fs: Substitute bit-spinlocks for PREEMPT_RT and

On Sat, Aug 10, 2019 at 01:18:34AM -0700, Christoph Hellwig wrote:
> On Thu, Aug 08, 2019 at 09:54:03AM +0200, Thomas Gleixner wrote:
> > > I know.  But the problem here is that normally PG_locked is used together 
> > > with wait_on_page_bit_*, but this one instances uses the bit spinlock
> > > helpers.  This is the equivalent of calling spin_lock on a struct mutex
> > > rather than having a mutex_lock_spin helper for this case.
> > 
> > Yes, I know :(
> But this means we should exclude slub from the bit_spin_lock removal.
> It really should use it's own version of it anyhow insted of pretending
> that the page lock is a bit spinlock.

But PG_locked isn't used as a mutex _when the page is allocated by slab_.
Yes, every other user uses PG_locked as a mutex, but I don't see why that
should constrain slub's usage of PG_locked.

Powered by blists - more mailing lists