Re: Strong kernel lock with linux-2.5.59 : futex in Huge Pages

• Next message: Anders Gustafsson: "Re: Cryptoloop in Linux 2.5"
• Previous message: Denis Vlasenko: "lk maintainers with first 2003 entry :)"
• In reply to: dada1: "Strong kernel lock with linux-2.5.59 : futex in Huge Pages"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

"dada1" <dada1@cosmosbay.com> wrote:
>
> Hello
>
> I found a way to lock a linux-2.5.59 in all cases, in using futexes landing
> in a HugeTLB page.
>
> You need to be root to be able to obtain HugePages (or CAP_IPC_LOCK
> capability)
>
> I suspect that the kernel/futex.c:__pin_page(unsigned long addr) or
> mm/memory.c:follow_page() are not HugeTLB page aware.
>
> How you can reproduce it. (dont do it of course, unless you really want to
> debug the thing)

Yup, futexes and direct-io against hugepages are bust. I was going to fix
that up this week, but got distracted.

-
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/

• Next message: Anders Gustafsson: "Re: Cryptoloop in Linux 2.5"
• Previous message: Denis Vlasenko: "lk maintainers with first 2003 entry :)"
• In reply to: dada1: "Strong kernel lock with linux-2.5.59 : futex in Huge Pages"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This archive was generated by hypermail 2b29 : Thu Jan 23 2003 - 22:00:31 EST