Thread (8 messages) 8 messages, 4 authors, 2012-01-09

[RFC PATCH 0/9] Remove useless on_each_cpu return value

From: Michal Nazarewicz <hidden>
Date: 2012-01-03 14:26:18
Also in: dri-devel, linux-alpha, linux-devicetree, linuxppc-dev, lkml

On Tue, 03 Jan 2012 15:19:04 +0100, Gilad Ben-Yossef [off-list ref] wrote:
on_each_cpu() returns as its own return value the return value of
smp_call_function(). smp_call_function() in turn returns a hard
coded value of zero.

Some callers to on_each_cpu() waste cycles and bloat code space
by checking the return value to on_each_cpu(), probably for
historical reasons.

This patch set refactors callers to not test on_each_cpu()
(fixed) return value and then refactors on_each_cpu to
return void to avoid confusing future users.

In other words, this patch aims to delete 18 source code lines
while not changing any functionality :-)

I tested as best as I could the x86 changes and compiled some
of the others, but I don't have access to all the needed hardware
for testing. Reviewers and testers welcome!
Other then the lack of Signed-off-by in the patches, looks good to me,
even though personally I'd choose a bottom-up approach, ie. make
smp_call_function() return void and from that conclude that
on_each_cpu() can return void.  With those patches, we have a situation,
where smp_call_function() has a return value which is then lost for no
immediately apparent reason lost in on_each_cpu().

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Micha? ?mina86? Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo--
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help