linux-kernel - Re: [PATCH] percpu_counter : add percpu_counter_add

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.00.1010211807280.3431@router.home>
Date:	Thu, 21 Oct 2010 18:10:13 -0500 (CDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
cc:	Eric Dumazet <eric.dumazet@...il.com>,
	Nick Piggin <npiggin@...nel.dk>,
	Dave Chinner <david@...morbit.com>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] percpu_counter : add percpu_counter_add_fast()

On Thu, 21 Oct 2010, Andrew Morton wrote:

> That isn't actually what I was suggesting.  I was suggesting the use of
> an inlined, this_cpu_add()-using percpu_counter_add() variant which
> still does the batched spilling into ->count.  IOW, just speed up the
> current implementation along the lines of
>
> {
> 	val = this_cpu_add_return(*fbc->counters, amount);

this_cpu_add_return() is not in the kernel but could be realized using a
variant offshoot of cmpxchg_local. I had something like that initially but
omitted it since there was no use case.

--
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/