linux-kernel - Re: [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast

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: <546B694D.3080604@redhat.com>
Date:	Tue, 18 Nov 2014 07:44:13 -0800
From:	Alexander Duyck <alexander.h.duyck@...hat.com>
To:	David Laight <David.Laight@...LAB.COM>,
	"linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	"mathieu.desnoyers@...ymtl.ca" <mathieu.desnoyers@...ymtl.ca>,
	"peterz@...radead.org" <peterz@...radead.org>,
	"benh@...nel.crashing.org" <benh@...nel.crashing.org>,
	"heiko.carstens@...ibm.com" <heiko.carstens@...ibm.com>,
	"mingo@...nel.org" <mingo@...nel.org>,
	"mikey@...ling.org" <mikey@...ling.org>,
	"linux@....linux.org.uk" <linux@....linux.org.uk>,
	"donald.c.skidmore@...el.com" <donald.c.skidmore@...el.com>,
	"matthew.vick@...el.com" <matthew.vick@...el.com>,
	"geert@...ux-m68k.org" <geert@...ux-m68k.org>,
	"jeffrey.t.kirsher@...el.com" <jeffrey.t.kirsher@...el.com>,
	"romieu@...zoreil.com" <romieu@...zoreil.com>,
	"paulmck@...ux.vnet.ibm.com" <paulmck@...ux.vnet.ibm.com>,
	"nic_swsd@...ltek.com" <nic_swsd@...ltek.com>,
	"will.deacon@....com" <will.deacon@....com>,
	"michael@...erman.id.au" <michael@...erman.id.au>,
	"tony.luck@...el.com" <tony.luck@...el.com>,
	"torvalds@...ux-foundation.org" <torvalds@...ux-foundation.org>,
	"oleg@...hat.com" <oleg@...hat.com>,
	"schwidefsky@...ibm.com" <schwidefsky@...ibm.com>,
	"fweisbec@...il.com" <fweisbec@...il.com>,
	"davem@...emloft.net" <davem@...emloft.net>
Subject: Re: [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast_wmb()


On 11/18/2014 01:57 AM, David Laight wrote:
> From: Alexander Duyck
>> These patches introduce two new primitives for synchronizing cache-enabled
>> memory writes and reads.  These two new primitives are:
>>
>> 	fast_rmb()
>> 	fast_wmb()
> Not sure I like the names.
> If the aim is to sync data into the local cache so that hardware
> that is doing cache-snooping accesses sees the data then maybe
> 	local_rmb() and local_wmb()

Yeah, that is the general consensus.  I am planning to change them to 
coherent_rmb() and coherent_wmb().

> IIRC read_barrier_depends() is a nop on everything except alpha.
> Maybe add the default if it isn't defined by the MD file?
>
> 	David
>   

 From my patch the only two I saw define it were alpha and blackfin. It 
is already defined in asm-generic, the rest is just clean-up since I 
suspect some of the arch tree barrier.h calls just borrowed from 
asm-generic without sorting out what became redundancies.

Thanks,

Alex
--
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/