Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 22 Aug 2003 09:39:00 -0700 | From | "David S. Miller" <> | Subject | Re: [parisc-linux] Re: Problems with kernel mmap (failing tst-mmap-eofsync in glibc on parisc) |
| |
On Fri, 22 Aug 2003 17:34:29 +0100 Matthew Wilcox <willy@debian.org> wrote:
> On Fri, Aug 22, 2003 at 09:14:47AM -0700, David S. Miller wrote: > > On 22 Aug 2003 09:40:37 -0500 > > flush_dcache_page() checks both the shared and non-shared mmap lists, > > so if it is on _either_ list it is flushed. It does not check only > > the shared list. > > Gah, that's going to get really inefficient. I still think we want to > split flush_dcache_page() into two operations -- flush_dcache_user() and > flush_dcache_kernel(). flush_dcache_user() would flush this specific > user mapping back to ram and flush_dcache_kernel() would flush the > kernel mapping. Obviously we'd still want to have flush_dcache_page() > as there are instances when you want to flush all user mappings and the > kernel mapping back to ram.
flush_dcache_page() works only on kernel pages.
It is defined to execute when the kernel executes store instructions into a page.
Therefore splitting it into a "user" part makes absolutely no sense.
> > The VM_SHARED change you are proposing is definitely wrong. > > Why is it wrong? Why should whether-or-not a mapping is read-only affect > whether it's mapped shared? I can't see anything in SuS v3 that suggests > we should do this.
MAP_SHARED has no meaning if the mapping isn't writable. - 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/
| ![\](/images/icornerr.gif) |