Messages in this thread | | | Date | Wed, 18 Mar 2009 16:54:33 -0700 | Subject | Re: ftruncate-mmap: pages are lost after writing to mmaped file. | From | Ying Han <> |
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On Wed, Mar 18, 2009 at 4:36 PM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > > On Wed, 18 Mar 2009, Ying Han wrote: >> > >> > Can you say what filesystem, and what mount-flags you use? Iirc, last time >> > we had MAP_SHARED lost writes it was at least partly triggered by the >> > filesystem doing its own flushing independently of the VM (ie ext3 with >> > "data=journal", I think), so that kind of thing does tend to matter. >> >> /etc/fstab >> "/dev/hda1 / ext2 defaults 1 0" > > Sadly, /etc/fstab is not necessarily accurate for the root filesystem. At > least Fedora will ignore the flags in it. > > What does /proc/mounts say? That should be a more reliable indication of > what the kernel actually does.
"/dev/root / ext2 rw,errors=continue 0 0"
> > That said, I assume the ext2 part is accurate. Maybe that's why people > haven't seen it - I guess most testing was done on ext3. It certainly was > for me. > >> > Ying Han - since you're all set up for testing this and have reproduced it >> > on multiple kernels, can you try it on a few more kernel versions? It >> > would be interesting to both go further back in time (say 2.6.15-ish), >> > _and_ check something like 2.6.21 which had the exact dirty accounting >> > fix. Maybe it's not really an old bug - maybe we re-introduced a bug that >> > was fixed for a while. >> >> I will give a try. > > Thanks, > > Linus >
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