Hello Linus, On Thu, May 29, 2014 at 08:24:49AM -0700, Linus Torvalds wrote: > On Thu, May 29, 2014 at 12:26 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > What concerns me about both __alloc_pages_nodemask() and > > kernel_map_pages is that when I look at the code I see functions > > that have no obvious stack usage problem. However, the compiler is > > producing functions with huge stack footprints and it's not at all > > obvious when I read the code. So in this case I'm more concerned > > that we have a major disconnect between the source code structure > > and the code that the compiler produces... > > I agree. In fact, this is the main reason that Minchan's call trace > and this thread has actually convinced me that yes, we really do need > to make x86-64 have a 16kB stack (well, 16kB allocation - there's > still the thread info etc too). > > Usually when we see the stack-smashing traces, they are because > somebody did something stupid. In this case, there are certainly > stupid details, and things I think we should fix, but there is *not* > the usual red flag of "Christ, somebody did something _really_ wrong". > > So I'm not in fact arguing against Minchan's patch of upping > THREAD_SIZE_ORDER to 2 on x86-64, but at the same time stack size does > remain one of my "we really need to be careful" issues, so while I am > basically planning on applying that patch, I _also_ want to make sure > that we fix the problems we do see and not just paper them over. So, should I resend a patch w/o RFC in subject but with Acked-by from Dave? Or, you will do it by yourself? > > The 8kB stack has been somewhat restrictive and painful for a while, > and I'm ok with admitting that it is just getting _too_ damn painful, > but I don't want to just give up entirely when we have a known deep > stack case. > > Linus > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>