On Tue, Oct 25, 2016 at 12:21:22AM -0700, Christoph Hellwig wrote: > On Tue, Oct 25, 2016 at 03:13:17AM +0300, Kirill A. Shutemov wrote: > > We are going to do IO a huge page a time. So we need BIO_MAX_PAGES to be > > at least HPAGE_PMD_NR. For x86-64, it's 512 pages. > > NAK. The maximum bio size should not depend on an obscure vm config, > please send a standalone patch increasing the size to the block list, > with a much long explanation. Also you can't simply increase the size > of the largers pool, we'll probably need more pools instead, or maybe > even implement a similar chaining scheme as we do for struct > scatterlist. The size of required pool depends on architecture: different architectures has different (huge page size)/(base page size). Would it be okay if I add one more pool with size equal to HPAGE_PMD_NR, if it's bigger than than BIO_MAX_PAGES and huge pages are enabled? -- Kirill A. Shutemov -- 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>