On Fri, Feb 17, 2012 at 1:22 AM, Zheng Liu <gnehzuil.liu@xxxxxxxxx> 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? One of changes after the split-lru is different scan ratio (active vs inactive) for file-lru and anon-lru. You can check the following two functions: inactive_anon_is_low_global() inactive_file_is_low_global() Depends on your machine size, we might end of scanning more pages on file lru. --Ying The index file > should be replaced because mmap doesn't impact the lru list. > > 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