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  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, 18 Aug 2007 15:41:13 -0700 (PDT)
From:	Linus Torvalds <>
To:	"Paul E. McKenney" <>
cc:	Satyam Sharma <>,
	Christoph Lameter <>,
	Herbert Xu <>,
	Nick Piggin <>,
	Paul Mackerras <>,
	Segher Boessenkool <>,,,,,,,,,,,,,
	Chris Snook <>,,,
Subject: Re: [PATCH 0/24] make atomic_read() behave consistently across all

On Sat, 18 Aug 2007, Paul E. McKenney wrote:
> One of the gcc guys claimed that he thought that the two-instruction
> sequence would be faster on some x86 machines.  I pointed out that
> there might be a concern about code size.  I chose not to point out
> that people might also care about the other x86 machines.  ;-)

Some (very few) x86 uarchs do tend to prefer "load-store" like code 
generation, and doing a "mov [mem],reg + op reg" instead of "op [mem]" can 
actually be faster on some of them. Not any that are relevant today, 

Also, that has nothing to do with volatile, and should be controlled by 
optimization flags (like -mtune). In fact, I thought there was a separate 
flag to do that (ie something like "-mload-store"), but I can't find it, 
so maybe that's just my fevered brain..

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists