On Tue, Mar 13, 2012 at 01:17:41PM +0530, Kautuk Consul wrote: > On Tue, Mar 13, 2012 at 1:13 PM, Kautuk Consul <consul.kautuk@xxxxxxxxx> wrote: > > Hi, > > > > I noticed this discussion and decided to pitch in one small idea from my side. > > > > It would be nice to range lock an inode's pages by storing those > > ranges which would be locked. > > This could also add some good routines for the kernel in terms of > > range locking for a single inode. > > However, wouldn't this add some overhead to shrink_page_list() since > > that code would need to go through > > all these ranges while trying to reclaim a single page ? > > > > One small suggestion from my side is: > > Why don't we implement something like : "Complete page-cache reclaim > > control from usermode"? > > In this, we can set/unset the mapping to AS_UNEVICTABLE (as Konstantin > > mentioned) for a file's > > inode from usermode by using ioctl or fcntl or maybe even go as far as > > implementing an O_NORECL > > option to the open system call. > > > > Of course, only an application executing with root privileges should > be allowed to set the inode's > mapping flags in this manner. Hi Kautuk, IMHO, running application with root privilege is too dangerous. We should avoid it. Regards, Zheng > > > > After setting the AS_UNEVICTABLE, the usermode application can choose > > to keep and remove pages by > > using the fadvise(WILLNEED) and fadvise(DONTNEED). > > > > ( I think maybe the presence of any VMA is might not really be > > required for this idea. ) > > > > Thanks, > > Kautuk. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>