[lkml]   [2005]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 1/1] Implement shared page tables
On Wed, 31 Aug 2005, Martin J. Bligh wrote:
> --Hugh Dickins <> wrote (on Wednesday, August 31, 2005 14:42:38 +0100):
> >
> > Which is indeed a further disincentive against shared page tables.
> Or shared pagetables a disincentive to randomizing the mmap space ;-)

Fair point!

> They're incompatible, but you could be left to choose one or the other
> via config option.

Wouldn't need config option: there's /proc/sys/kernel/randomize_va_space
for the whole running system, compatibility check on the ELFs run, and
the infinite stack rlimit: enough ways to suppress randomization if it
doesn't suit you.

> 3% on "a certain industry-standard database benchmark" (cough) is huge,
> and we expect the benefit for PPC64 will be larger as we can share the
> underlying hardware PTEs without TLB flushing as well.

Okay - and you're implying that 3% comes from _using_ the shared page
tables, rather than from avoiding the fork/exit overhead of setting
them up and tearing them down. And it can't use huge TLB pages
because... fragmentation?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-08-31 17:06    [W:0.040 / U:6.844 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site