On Wed, 2012-09-05 at 17:13 +0200, Paolo Bonzini wrote: > Hi all, > > while testing PSCSI I noticed that even requests for a smallish amount > of data (approximately 700 KB) failed due to an excessive number of > segments in the request. In fact, using alloc_page resulted in a > completely fragmented request, with no merging of consecutive pages > at all. > > This patch series fixes this problem by using higher-order allocations > to build the data scatterlist. The problem is that iscsi assumes that the > scatterlist consists of single pages, which is not true anymore. So > patch 2 has to introduce some relatively complicated changes to > iscsi_map_iovec and iscsi_unmap_iovec. > So enabling multi-page per SGL support is a feature that has been dormant within target core for a long time. It's about time that we start taking advantage of it again. ;) > While doing this, I noticed something strange in iscsit_do_crypto_hash_sg. > Patch 1 adds a warning about it. > Mmmmm, looks like a separate bug with DataDigest enabled. > The approach may be completely wrong and it needs more testing anyway. > Please review! > Adding my comments inline. Thanks Paolo! --nab > Paolo > > Paolo Bonzini (3): > tcm_iscsi: warn on incorrect precondition for iscsit_do_crypto_hash_sg > tcm_iscsi: support multiple sizes in the scatterlist > target: try satisfying memory requests with contiguous blocks > > drivers/target/iscsi/iscsi_target.c | 106 +++++++++++++++++++++++++----- > drivers/target/iscsi/iscsi_target_core.h | 2 +- > drivers/target/target_core_transport.c | 58 ++++++++++++++--- > 3 files changed, 138 insertions(+), 28 deletions(-) > > -- > To unsubscribe from this list: send the line "unsubscribe target-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
