Scott Bennett wrote: > On Tue, 13 Apr 2010 19:10:37 +0200 Arjan > <n6bc23cpc...@list.nospam.xutrox.com> wrote: >> Scott Bennett wrote: >>> BTW, I know that there are *lots* of tor relays running on LINUX >>> systems whose operators are subscribed to this list. Don't leave Olaf and >>> me here swinging in the breeze. Please jump in with your LINUX expertise >>> and straighten us out. >> I'm not an expert, but I managed to perform some google searches. >> >> http://libhugetlbfs.ozlabs.org/ >> >From that website: >> libhugetlbfs is a library which provides easy access to huge pages of >> memory. It is a wrapper for the hugetlbfs file system. Applications can >> use huge pages to fulfill malloc() requests without being recompiled by >> using LD_PRELOAD. > > [Aside to Olaf: oh. So forcing the use of OpenBSD's malloc() might > prevent the libhugetlbfs stuff from ever knowing that it was supposed to > do something. :-( I wonder how hard it would be to fix the malloc() in > libhugetlbfs, which is most likely derived from the buggy LINUX version. > Does libhugetlbfs come as source code? Or is the use of LD_PRELOAD simply > causing LINUX's libc to appear ahead of the OpenBSD version, in which case > forcing reordering of the libraries might work? --SB]
If Olafs test shows that CPU usage is reduced and throughput stays the same or improves, modifying Tor to support linux huge pages might be an option. Part 2 of this article contains some information about the available interfaces: http://lwn.net/Articles/374424/ Getting the wrapper to work with (or like) the OpenBSD version will probably be easier. >> Someone is working on transparent hugepage support: >> http://thread.gmane.org/gmane.linux.kernel.mm/40182 > > I've now had time to get through that entire thread. I found it > kind of frustrating reading at times. It seemed to me that in one of > the very first few messages, the author described how they had long > since shot themselves in the feet (i.e., by rejecting the algorithm of > Navarro et al. (2002), which had already been demonstrated to work on an early > FreeBSD 5 system modified by Navarro's team) on emotional grounds (i.e., > "we didn't feel its [Navarro's method's] heuristics were right"). <snipped the remainder of the analysis> Thanks for your analysis of the thread and the reference to the Navarro paper. I've located the paper and will read it when time permits: http://www.usenix.org/events/osdi02/tech/full_papers/navarro/ *********************************************************************** To unsubscribe, send an e-mail to majord...@torproject.org with unsubscribe or-talk in the body. http://archives.seul.org/or/talk/