On Fri, Aug 21, 2015 at 10:12 AM, Roman Gushchin <klamm@xxxxxxxxxxxxxx> wrote: > > There are devices, which require custom readahead limit. > For instance, for RAIDs it's calculated as number of devices > multiplied by chunk size times 2. So afaik, the default read-ahead size is 128kB, which is actually smaller than the old 512-page limit. Which means that you probably changed "ra_pages" somehow. Is it some system tool that does that automatically, and if so based on what, exactly? I'm also slightly worried about the fact that now the max read-ahead may actually be zero, and/or basically infinite (there's a ioctl to set it that only tests that it's not negative). Does everything react ok to that? Linus -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>