From patchwork Mon Oct 10 09:11:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13002378 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3CFCDC433F5 for ; Mon, 10 Oct 2022 09:14:12 +0000 (UTC) Received: from localhost ([::1]:50104 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ohorT-0006QO-AZ for qemu-devel@archiver.kernel.org; Mon, 10 Oct 2022 05:14:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41942) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ohopC-0003ad-BB for qemu-devel@nongnu.org; Mon, 10 Oct 2022 05:11:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:53252) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ohop4-00011L-ID for qemu-devel@nongnu.org; Mon, 10 Oct 2022 05:11:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665393101; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/iUqoR3jSAOwGR+0kZWjYXliTHkpXJJ3VhSOj1j8buc=; b=TKiaPZT4WUPBFyYalmsoqrGwdf17W1wfVY4OFsrDsCZzNj2oEXbYrn8K31D/9VSzSqhXE4 /w3Efm8tMHhUx/uysofvFmhnfoT25VS9EZOGuheZvTO9je3jZHDIHQmh9KKpBUa2fj8Iv2 GQJBACLfaRrP2XEIMKxfACAUHQdJ6+k= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-618-fwNnnmCfMleiGJzDjyYz5w-1; Mon, 10 Oct 2022 05:11:38 -0400 X-MC-Unique: fwNnnmCfMleiGJzDjyYz5w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8191E185A7A4; Mon, 10 Oct 2022 09:11:38 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.119]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4B80F1121314; Mon, 10 Oct 2022 09:11:36 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: David Hildenbrand , Michal Privoznik , Igor Mammedov , "Michael S. Tsirkin" , Paolo Bonzini , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Eduardo Habkost , "Dr . David Alan Gilbert" , Eric Blake , Markus Armbruster , Richard Henderson , Stefan Weil Subject: [PATCH v2 6/7] hostmem: Allow for specifying a ThreadContext for preallocation Date: Mon, 10 Oct 2022 11:11:16 +0200 Message-Id: <20221010091117.88603-7-david@redhat.com> In-Reply-To: <20221010091117.88603-1-david@redhat.com> References: <20221010091117.88603-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Let's allow for specifying a thread context via the "prealloc-context" property. When set, preallcoation threads will be crated via the thread context -- inheriting the same CPU affinity as the thread context. Pinning preallcoation threads to CPUs can heavily increase performance in NUMA setups, because, preallocation from a CPU close to the target NUMA node(s) is faster then preallocation from a CPU further remote, simply because of memory bandwidth for initializing memory with zeroes. This is especially relevant for very large VMs backed by huge/gigantic pages, whereby preallocation is mandatory. Reviewed-by: Michal Privoznik Signed-off-by: David Hildenbrand --- backends/hostmem.c | 12 +++++++++--- include/sysemu/hostmem.h | 2 ++ qapi/qom.json | 4 ++++ 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/backends/hostmem.c b/backends/hostmem.c index 76f0394490..8640294c10 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -232,8 +232,8 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value, void *ptr = memory_region_get_ram_ptr(&backend->mr); uint64_t sz = memory_region_size(&backend->mr); - qemu_prealloc_mem(fd, ptr, sz, backend->prealloc_threads, NULL, - &local_err); + qemu_prealloc_mem(fd, ptr, sz, backend->prealloc_threads, + backend->prealloc_context, &local_err); if (local_err) { error_propagate(errp, local_err); return; @@ -385,7 +385,8 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp) */ if (backend->prealloc) { qemu_prealloc_mem(memory_region_get_fd(&backend->mr), ptr, sz, - backend->prealloc_threads, NULL, &local_err); + backend->prealloc_threads, + backend->prealloc_context, &local_err); if (local_err) { goto out; } @@ -493,6 +494,11 @@ host_memory_backend_class_init(ObjectClass *oc, void *data) NULL, NULL); object_class_property_set_description(oc, "prealloc-threads", "Number of CPU threads to use for prealloc"); + object_class_property_add_link(oc, "prealloc-context", + TYPE_THREAD_CONTEXT, offsetof(HostMemoryBackend, prealloc_context), + object_property_allow_set_link, OBJ_PROP_LINK_STRONG); + object_class_property_set_description(oc, "prealloc-context", + "Context to use for creating CPU threads for preallocation"); object_class_property_add(oc, "size", "int", host_memory_backend_get_size, host_memory_backend_set_size, diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h index 9ff5c16963..39326f1d4f 100644 --- a/include/sysemu/hostmem.h +++ b/include/sysemu/hostmem.h @@ -18,6 +18,7 @@ #include "qom/object.h" #include "exec/memory.h" #include "qemu/bitmap.h" +#include "qemu/thread-context.h" #define TYPE_MEMORY_BACKEND "memory-backend" OBJECT_DECLARE_TYPE(HostMemoryBackend, HostMemoryBackendClass, @@ -66,6 +67,7 @@ struct HostMemoryBackend { bool merge, dump, use_canonical_path; bool prealloc, is_mapped, share, reserve; uint32_t prealloc_threads; + ThreadContext *prealloc_context; DECLARE_BITMAP(host_nodes, MAX_NODES + 1); HostMemPolicy policy; diff --git a/qapi/qom.json b/qapi/qom.json index cb6f700c0c..efa74f9799 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -578,6 +578,9 @@ # # @prealloc-threads: number of CPU threads to use for prealloc (default: 1) # +# @prealloc-context: thread context to use for creation of preallocation threads +# (default: none) (since 7.2) +# # @share: if false, the memory is private to QEMU; if true, it is shared # (default: false) # @@ -608,6 +611,7 @@ '*policy': 'HostMemPolicy', '*prealloc': 'bool', '*prealloc-threads': 'uint32', + '*prealloc-context': 'str', '*share': 'bool', '*reserve': 'bool', 'size': 'size',