From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: gcc inlining heuristics was Re: [PATCH -v7][RFC]: mutex: implement adaptive spinning Date: Sun, 11 Jan 2009 12:51:31 -0800 (PST) Message-ID: References: <20090109231227.GA25070@elte.hu> <20090110010125.GA31031@elte.hu> <20090109174158.096dee70.akpm@linux-foundation.org> <20090110030216.GW26290@one.firstfloor.org> <1231676801.25018.150.camel@macbook.infradead.org> <20090111181307.GM26290@one.firstfloor.org> <20090111201427.GP26290@one.firstfloor.org> <1231704939.25018.548.camel@macbook.infradead.org> <20090111203441.GQ26290@one.firstfloor.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: David Woodhouse , Andrew Morton , Ingo Molnar , Harvey Harrison , "H. Peter Anvin" , Chris Mason , Peter Zijlstra , Steven Rostedt , paulmck@linux.vnet.ibm.com, Gregory Haskins , Matthew Wilcox , Linux Kernel Mailing List , linux-fsdevel , linux-btrfs , Thomas Gleixner , Nick Piggin , Peter Morreale , Sven Dietrich , jh@suse.cz To: Andi Kleen Return-path: In-Reply-To: <20090111203441.GQ26290@one.firstfloor.org> List-ID: On Sun, 11 Jan 2009, Andi Kleen wrote: > > Was -- i think that got fixed in gcc. But again only in newer versions. I doubt it. People have said that about a million times, it has never gotten fixed, and I've never seen any actual proof. I think that what got fixed was that gcc now at least re-uses stack slots for temporary spills. But only for things that fit in registers - not if you actually had variables that are big enough to be of type MEM. And the latter is what tends to eat stack-space (ie structures etc on stack). But hey, maybe it really did get fixed. But the last big stack user wasn't that long ago, and I saw it and I have a pretty recent gcc (gcc-4.3.2 right now, it could obviously have been slightly older back a few months ago). Linus