Cc linux-kernel mailing list. On Sat, Feb 18, 2012 at 12:20:05AM +0400, Konstantin Khlebnikov wrote: > Zheng Liu wrote: > >Hi all, > > > >Currently, we encounter a problem about page reclaim. In our product system, > >there is a lot of applictions that manipulate a number of files. In these > >files, they can be divided into two categories. One is index file, another is > >block file. The number of index files is about 15,000, and the number of > >block files is about 23,000 in a 2TB disk. The application accesses index > >file using mmap(2), and read/write block file using pread(2)/pwrite(2). We hope > >to hold index file in memory as much as possible, and it works well in Redhat > >2.6.18-164. It is about 60-70% of index files that can be hold in memory. > >However, it doesn't work well in Redhat 2.6.32-133. I know in 2.6.18 that the > >linux uses an active list and an inactive list to handle page reclaim, and in > >2.6.32 that they are divided into anonymous list and file list. So I am > >curious about why most of index files can be hold in 2.6.18? The index file > >should be replaced because mmap doesn't impact the lru list. > > There was my patch for fixing similar problem with shared/executable mapped pages > "vmscan: promote shared file mapped pages" commit 34dbc67a644f and commit c909e99364c > maybe it will help in your case. Hi Konstantin, Thank you for your reply. I have tested it in upstream kernel. These patches are useful for multi-processes applications. But, in our product system, there are some applications that are multi-thread. So 'references_ptes > 1' cannot help these applications to hold the data in memory. Regards, Zheng > > > > >BTW, I have some problems that need to be discussed. > > > >1. I want to let index and block files are separately reclaimed. Is there any > >ways to satisify me in current upstream? > > > >2. Maybe we can provide a mechansim to let different files to be mapped into > >differnet nodes. we can provide a ioctl(2) to tell kernel that this file should > >be mapped into a specific node id. A nid member is added into addpress_space > >struct. When alloc_page is called, the page can be allocated from that specific > >node id. > > > >3. Currently the page can be reclaimed according to pid in memcg. But it is too > >coarse. I don't know whether memcg could provide a fine granularity page > >reclaim mechansim. For example, the page is reclaimed according to inode number. > > > >I don't subscribe this mailing list, So please Cc me. Thank you. > > > >Regards, > >Zheng > > > >-- > >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>