From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andres Lagar-Cavilla Subject: [PATCH 0 of 2] x86/mm: Switch paging/sharing/access per-page ops to memops Date: Wed, 01 Feb 2012 15:09:38 -0500 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: ian.campbell@citrix.com, andres@gridcentric.ca, tim@xen.org, keir.xen@gmail.com, JBeulich@suse.com, ian.jackson@citrix.com, adin@gridcentric.ca List-Id: xen-devel@lists.xenproject.org Per page operations in the paging, sharing, and access tracking subsystems are all implemented with domctls (e.g. a domctl to evict one page, or to share one page). Under heavy load, the domctl path reveals a lack of scalability. The domctl lock serializes dom0's vcpus in the hypervisor. When performing thousands of per-page operations on dozens of domains, these vcpus will spin in the hypervisor. Beyond the aggressive locking, an added inefficiency of blocking vcpus in the domctl lock is that dom0 is prevented from re-scheduling any of its other work-starved processes. We retain the domctl interface for setting up and tearing down paging/sharing/mem access for a domain. But we migrate all the per page operations to use the memory_op hypercalls (e.g XENMEM_*). A new tools-only section is added to the public memory.h header. This is a backwards-incompatible ABI change. It's been floating on the list for a couple weeks now, with no nacks thus far. Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Adin Scannell tools/libxc/xc_mem_access.c | 12 +- tools/libxc/xc_mem_event.c | 23 +++- tools/libxc/xc_mem_paging.c | 44 ++++---- tools/libxc/xc_memshr.c | 182 ++++++++++++++++------------------ tools/libxc/xenctrl.h | 6 +- tools/memshr/interface.c | 4 +- tools/tests/mem-sharing/memshrtool.c | 4 +- xen/arch/x86/domctl.c | 1 - xen/arch/x86/mm/mem_access.c | 7 +- xen/arch/x86/mm/mem_event.c | 68 ++++++++++-- xen/arch/x86/mm/mem_paging.c | 13 +- xen/arch/x86/mm/mem_sharing.c | 99 +++++++++++------- xen/arch/x86/x86_64/compat/mm.c | 23 ++++ xen/arch/x86/x86_64/mm.c | 23 ++++ xen/include/asm-x86/mem_access.h | 3 +- xen/include/asm-x86/mem_event.h | 2 + xen/include/asm-x86/mem_paging.h | 3 +- xen/include/asm-x86/mem_sharing.h | 3 + xen/include/public/domctl.h | 90 +++------------- xen/include/public/memory.h | 87 ++++++++++++++++ tools/libxc/xc_memshr.c | 11 ++ tools/libxc/xenctrl.h | 1 + tools/tests/mem-sharing/memshrtool.c | 11 ++ xen/arch/x86/mm/mem_sharing.c | 13 +- xen/arch/x86/x86_64/compat/mm.c | 3 + xen/arch/x86/x86_64/mm.c | 2 + xen/include/asm-x86/mem_sharing.h | 3 +- xen/include/public/memory.h | 1 + 28 files changed, 458 insertions(+), 284 deletions(-)