From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60089) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WIFA9-0002rB-TZ for qemu-devel@nongnu.org; Tue, 25 Feb 2014 05:23:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WIFA5-0002mg-A2 for qemu-devel@nongnu.org; Tue, 25 Feb 2014 05:22:57 -0500 Received: from [222.73.24.84] (port=54376 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WIFA4-0002lu-Re for qemu-devel@nongnu.org; Tue, 25 Feb 2014 05:22:53 -0500 Date: Tue, 25 Feb 2014 18:20:59 +0800 From: Hu Tao Message-ID: <20140225102059.GA20627@G08FNSTD100614.fnst.cn.fujitsu.com> References: <53047351.80300@redhat.com> <20140219103657.4daed264@nial.usersys.redhat.com> MIME-Version: 1.0 In-Reply-To: <20140219103657.4daed264@nial.usersys.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Subject: Re: [Qemu-devel] [PATCH v18 13/14] memory backend: fill memory backend ram fields List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: Paolo Bonzini , lersek@redhat.com, qemu-devel@nongnu.org, Wanlong Gao On Wed, Feb 19, 2014 at 10:36:57AM +0100, Igor Mammedov wrote: > On Wed, 19 Feb 2014 10:03:13 +0100 > Paolo Bonzini wrote: > > > 19/02/2014 08:54, Hu Tao ha scritto: > > > Thus makes user control how to allocate memory for ram backend. > > > > > > Signed-off-by: Hu Tao > > > --- > > > backends/hostmem-ram.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++ > > > include/sysemu/sysemu.h | 2 + > > > 2 files changed, 160 insertions(+) > > > > > > diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c > [...] > > > > static int > > > ram_backend_memory_init(HostMemoryBackend *backend, Error **errp) > > > { > > > + HostMemoryBackendRam *ram_backend = MEMORY_BACKEND_RAM(backend); > > > + int mode = ram_backend->policy; > > > + void *p; > > > + unsigned long maxnode; > > > + > > > if (!memory_region_size(&backend->mr)) { > > > memory_region_init_ram(&backend->mr, OBJECT(backend), > > > object_get_canonical_path(OBJECT(backend)), > > > backend->size); > > > + > > > + p = memory_region_get_ram_ptr(&backend->mr); > > > + maxnode = find_last_bit(ram_backend->host_nodes, MAX_NODES); > > > + > > > + mode |= ram_backend->relative ? MPOL_F_RELATIVE_NODES : > > > + MPOL_F_STATIC_NODES; > > > + /* This is a workaround for a long standing bug in Linux' > > > + * mbind implementation, which cuts off the last specified > > > + * node. To stay compatible should this bug be fixed, we > > > + * specify one more node and zero this one out. > > > + */ > > > + if (syscall(SYS_mbind, p, backend->size, mode, > > > + ram_backend->host_nodes, maxnode + 2, 0)) { > > > > This does not compile on non-Linux; also, does libnuma include the > > workaround? If so, this is a hint that we should be using libnuma > > instead... > > > > Finally, all this code should be in hostmem.c, not hostmem-ram.c, > > because the same policies can be applied to hugepage-backed memory. > > > > Currently host_memory_backend_get_memory is calling bc->memory_init. > > Probably the call should be replaced by something like > I've pushed to github updated version of memdev, where > host_memory_backend_get_memory() is just convenience wrapper to get > access to memdev's internal MemoryRegion. > > All initialization now is done in user_creatable->complete() method > which calls ram_backend_memory_init() so leaving it as is should be fine. There is a problem that user_creatable_complete() is called before adding object to "/objects" (see object_create()), which triggers a assert failure when calling object_get_canonical_path() in ram_backend_memory_init(). Any ideas?