![]() | |||||||||||||
Messages in this thread |
Rusty Russell a écrit : > On Tue, 2006-10-31 at 15:09 -0800, akpm@osdl.org wrote: >> From: Andrew Morton <akpm@osdl.org> >> >> Apparently FUTEX_FD is unfixably racy and nothing uses it (or if it does, it >> shouldn't). >> >> Add a warning printk, give any remaining users six months to migrate off it. > > This makes sense. FUTEX_FD was for the NGPT project which did userspace > threading, and hence couldn't block. It was always kind of a hack > (although unfixably racy isn't quite right, it depends on usage). > > However, the existence of FUTEX_FD is what made Ingo complain that we > couldn't simply pin the futex page in memory, because now a process > could pin one page per fd. Removing it would seem to indicate that we > can return to a much simpler scheme of (1) pinning a page when someone > does futex_wait, and (2) simply comparing futexes by physical address. > > Now, I realize with some dismay that simplicity is no longer a futex > feature, but it might be worth considering? Hum... I am not sure playing MM games is good... really... This discussion reminds me I posted a patch some time ago that got no comments from the community. http://lkml.org/lkml/2006/8/9/26 Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2006-11-01 11:23 [from the cache] ©2003-2008 | |||||||||||||