Hi, I was wondering about the ARC and its interaction with the VM pagecache... When a file on a ZFS filesystem is mmaped, does the ARC cache get mapped to the process'' virtual memory? Or is there another copy? -Manoj
Manoj Joseph writes: > Hi, > > I was wondering about the ARC and its interaction with the VM > pagecache... When a file on a ZFS filesystem is mmaped, does the ARC > cache get mapped to the process'' virtual memory? Or is there another copy? > My understanding is, The ARC does not get mapped to user space. The data ends up in the ARC (recordsize chunks) and in the page cache (in page chunks). Both copies are updated on writes. -r > -Manoj > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
On 5/4/07, Roch - PAE <Roch.Bourbonnais at sun.com> wrote:> > Manoj Joseph writes: > > Hi, > > > > I was wondering about the ARC and its interaction with the VM > > pagecache... When a file on a ZFS filesystem is mmaped, does the ARC > > cache get mapped to the process'' virtual memory? Or is there another copy? > > > > My understanding is, > > The ARC does not get mapped to user space. The data ends up in the ARC > (recordsize chunks) and in the page cache (in page chunks). > Both copies are updated on writes.If that is the case, are there any plans to unify the ARC and the page cache? Thanks, - Ryan -- UNIX Administrator http://prefetch.net