[lkml]   [2007]   [Feb]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] update ctime and mtime for mmaped write
> > Inspired by Peter Staubach's patch and the resulting comments.
> >
> >
> An updated version of the original patch was submitted to LKML
> yesterday... :-)

Strange coincidence :)

> > file = vma->vm_file;
> > start = vma->vm_end;
> > + mapping_update_time(file);
> > if ((flags & MS_SYNC) && file &&
> > (vma->vm_flags & VM_SHARED)) {
> > get_file(file);
> >
> It seems to me that this might lead to file times being updated for
> non-MAP_SHARED mappings.

In theory no, because the COW-ed pages become anonymous and are not
part of the original mapping any more.

> > +int set_page_dirty_mapping(struct page *page);
> >
> This aspect of the design seems intrusive to me. I didn't see a strong
> reason to introduce new versions of many of the routines just to handle
> these semantics. What motivated this part of your design? Why the new
> _mapping versions of routines?

Because there's no way to know inside the set_page_dirty() functions
if the dirtying comes from a memory mapping or from a modification
through a normal write(). And they have different semantics, for
write() the modification times are updated immediately.

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: 2007-02-21 19:27    [W:0.087 / U:1.968 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site