From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URG_BIZ autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11396C5ACAE for ; Wed, 11 Sep 2019 19:11:13 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DEB2F2075C for ; Wed, 11 Sep 2019 19:11:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DEB2F2075C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55666 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i881I-0000Hq-0e for qemu-devel@archiver.kernel.org; Wed, 11 Sep 2019 15:11:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54091) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i87wk-0003yy-Pq for qemu-devel@nongnu.org; Wed, 11 Sep 2019 15:06:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i87wj-0006bH-Kz for qemu-devel@nongnu.org; Wed, 11 Sep 2019 15:06:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35462) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i87wj-0006an-C9 for qemu-devel@nongnu.org; Wed, 11 Sep 2019 15:06:29 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B3A015AFE3 for ; Wed, 11 Sep 2019 19:06:28 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-243.ams2.redhat.com [10.36.117.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 874F860167; Wed, 11 Sep 2019 19:06:27 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, pbonzini@redhat.com, ehabkost@redhat.com, berrange@redhat.com, quintela@redhat.com Date: Wed, 11 Sep 2019 20:06:19 +0100 Message-Id: <20190911190622.7629-3-dgilbert@redhat.com> In-Reply-To: <20190911190622.7629-1-dgilbert@redhat.com> References: <20190911190622.7629-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 11 Sep 2019 19:06:28 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/5] migration: Use automatic rcu_read unlock in ram.c X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 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" From: "Dr. David Alan Gilbert" Use the automatic read unlocker in migration/ram.c; only for the cases where the unlock is at the end of the function. Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index b2bd618a89..1bb82acfe0 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -181,14 +181,14 @@ int foreach_not_ignored_block(RAMBlockIterFunc func= , void *opaque) RAMBlock *block; int ret =3D 0; =20 - rcu_read_lock(); + RCU_READ_LOCK_AUTO; + RAMBLOCK_FOREACH_NOT_IGNORED(block) { ret =3D func(block, opaque); if (ret) { break; } } - rcu_read_unlock(); return ret; } =20 @@ -2398,13 +2398,12 @@ static void migration_page_queue_free(RAMState *r= s) /* This queue generally should be empty - but in the case of a faile= d * migration might have some droppings in. */ - rcu_read_lock(); + RCU_READ_LOCK_AUTO; QSIMPLEQ_FOREACH_SAFE(mspr, &rs->src_page_requests, next_req, next_m= spr) { memory_region_unref(mspr->rb->mr); QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); g_free(mspr); } - rcu_read_unlock(); } =20 /** @@ -2425,7 +2424,8 @@ int ram_save_queue_pages(const char *rbname, ram_ad= dr_t start, ram_addr_t len) RAMState *rs =3D ram_state; =20 ram_counters.postcopy_requests++; - rcu_read_lock(); + RCU_READ_LOCK_AUTO; + if (!rbname) { /* Reuse last RAMBlock */ ramblock =3D rs->last_req_rb; @@ -2467,12 +2467,10 @@ int ram_save_queue_pages(const char *rbname, ram_= addr_t start, ram_addr_t len) QSIMPLEQ_INSERT_TAIL(&rs->src_page_requests, new_entry, next_req); migration_make_urgent_request(); qemu_mutex_unlock(&rs->src_page_req_mutex); - rcu_read_unlock(); =20 return 0; =20 err: - rcu_read_unlock(); return -1; } =20 @@ -2712,7 +2710,8 @@ static uint64_t ram_bytes_total_common(bool count_i= gnored) RAMBlock *block; uint64_t total =3D 0; =20 - rcu_read_lock(); + RCU_READ_LOCK_AUTO; + if (count_ignored) { RAMBLOCK_FOREACH_MIGRATABLE(block) { total +=3D block->used_length; @@ -2722,7 +2721,6 @@ static uint64_t ram_bytes_total_common(bool count_i= gnored) total +=3D block->used_length; } } - rcu_read_unlock(); return total; } =20 @@ -3086,7 +3084,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState= *ms) RAMBlock *block; int ret; =20 - rcu_read_lock(); + RCU_READ_LOCK_AUTO; =20 /* This should be our last sync, the src is now paused */ migration_bitmap_sync(rs); @@ -3107,13 +3105,11 @@ int ram_postcopy_send_discard_bitmap(MigrationSta= te *ms) * point. */ error_report("migration ram resized during precopy phase"); - rcu_read_unlock(); return -EINVAL; } /* Deal with TPS !=3D HPS and huge pages */ ret =3D postcopy_chunk_hostpages(ms, block); if (ret) { - rcu_read_unlock(); return ret; } =20 @@ -3128,7 +3124,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState= *ms) trace_ram_postcopy_send_discard_bitmap(); =20 ret =3D postcopy_each_ram_send_discard(ms); - rcu_read_unlock(); =20 return ret; } @@ -3149,7 +3144,7 @@ int ram_discard_range(const char *rbname, uint64_t = start, size_t length) =20 trace_ram_discard_range(rbname, start, length); =20 - rcu_read_lock(); + RCU_READ_LOCK_AUTO; RAMBlock *rb =3D qemu_ram_block_by_name(rbname); =20 if (!rb) { @@ -3169,8 +3164,6 @@ int ram_discard_range(const char *rbname, uint64_t = start, size_t length) ret =3D ram_block_discard_range(rb, start, length); =20 err: - rcu_read_unlock(); - return ret; } =20 --=20 2.21.0