From nobody Sat Feb 7 06:49:18 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1486982166555297.7666813413118; Mon, 13 Feb 2017 02:36:06 -0800 (PST) Received: from localhost ([::1]:55663 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdDzJ-0006QD-9a for importer@patchew.org; Mon, 13 Feb 2017 05:36:05 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53680) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdDZf-0008Cg-0t for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cdDZd-0007dc-BF for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42570) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cdDZd-0007dT-2z for qemu-devel@nongnu.org; Mon, 13 Feb 2017 05:09:33 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 55B558046C for ; Mon, 13 Feb 2017 10:09:33 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-196.ams2.redhat.com [10.36.117.196]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1DA934s009201; Mon, 13 Feb 2017 05:09:32 -0500 From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 13 Feb 2017 11:09:05 +0100 Message-Id: <20170213100906.23486-18-pbonzini@redhat.com> In-Reply-To: <20170213100906.23486-1-pbonzini@redhat.com> References: <20170213100906.23486-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 13 Feb 2017 10:09:33 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 17/18] async: remove unnecessary inc/dec pairs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: famz@redhat.com, stefanha@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Pull the increment/decrement pair out of aio_bh_poll and into the callers. Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini --- util/aio-posix.c | 8 +++----- util/aio-win32.c | 8 ++++---- util/async.c | 12 ++++++------ 3 files changed, 13 insertions(+), 15 deletions(-) diff --git a/util/aio-posix.c b/util/aio-posix.c index e53434d..77cacdf 100644 --- a/util/aio-posix.c +++ b/util/aio-posix.c @@ -425,9 +425,8 @@ static bool aio_dispatch_handlers(AioContext *ctx) =20 void aio_dispatch(AioContext *ctx) { - aio_bh_poll(ctx); - qemu_lockcnt_inc(&ctx->list_lock); + aio_bh_poll(ctx); aio_dispatch_handlers(ctx); qemu_lockcnt_dec(&ctx->list_lock); =20 @@ -679,16 +678,15 @@ bool aio_poll(AioContext *ctx, bool blocking) } =20 npfd =3D 0; - qemu_lockcnt_dec(&ctx->list_lock); =20 progress |=3D aio_bh_poll(ctx); =20 if (ret > 0) { - qemu_lockcnt_inc(&ctx->list_lock); progress |=3D aio_dispatch_handlers(ctx); - qemu_lockcnt_dec(&ctx->list_lock); } =20 + qemu_lockcnt_dec(&ctx->list_lock); + progress |=3D timerlistgroup_run_timers(&ctx->tlg); =20 return progress; diff --git a/util/aio-win32.c b/util/aio-win32.c index 442a179..bca496a 100644 --- a/util/aio-win32.c +++ b/util/aio-win32.c @@ -253,8 +253,6 @@ static bool aio_dispatch_handlers(AioContext *ctx, HAND= LE event) bool progress =3D false; AioHandler *tmp; =20 - qemu_lockcnt_inc(&ctx->list_lock); - /* * We have to walk very carefully in case aio_set_fd_handler is * called while we're walking. @@ -305,14 +303,15 @@ static bool aio_dispatch_handlers(AioContext *ctx, HA= NDLE event) } } =20 - qemu_lockcnt_dec(&ctx->list_lock); return progress; } =20 void aio_dispatch(AioContext *ctx) { + qemu_lockcnt_inc(&ctx->list_lock); aio_bh_poll(ctx); aio_dispatch_handlers(ctx, INVALID_HANDLE_VALUE); + qemu_lockcnt_dec(&ctx->list_lock); timerlistgroup_run_timers(&ctx->tlg); } =20 @@ -349,7 +348,6 @@ bool aio_poll(AioContext *ctx, bool blocking) } } =20 - qemu_lockcnt_dec(&ctx->list_lock); first =3D true; =20 /* ctx->notifier is always registered. */ @@ -392,6 +390,8 @@ bool aio_poll(AioContext *ctx, bool blocking) progress |=3D aio_dispatch_handlers(ctx, event); } while (count > 0); =20 + qemu_lockcnt_dec(&ctx->list_lock); + progress |=3D timerlistgroup_run_timers(&ctx->tlg); return progress; } diff --git a/util/async.c b/util/async.c index cc40735..9c3ce6a 100644 --- a/util/async.c +++ b/util/async.c @@ -90,15 +90,16 @@ void aio_bh_call(QEMUBH *bh) bh->cb(bh->opaque); } =20 -/* Multiple occurrences of aio_bh_poll cannot be called concurrently */ +/* Multiple occurrences of aio_bh_poll cannot be called concurrently. + * The count in ctx->list_lock is incremented before the call, and is + * not affected by the call. + */ int aio_bh_poll(AioContext *ctx) { QEMUBH *bh, **bhp, *next; int ret; bool deleted =3D false; =20 - qemu_lockcnt_inc(&ctx->list_lock); - ret =3D 0; for (bh =3D atomic_rcu_read(&ctx->first_bh); bh; bh =3D next) { next =3D atomic_rcu_read(&bh->next); @@ -123,11 +124,10 @@ int aio_bh_poll(AioContext *ctx) =20 /* remove deleted bhs */ if (!deleted) { - qemu_lockcnt_dec(&ctx->list_lock); return ret; } =20 - if (qemu_lockcnt_dec_and_lock(&ctx->list_lock)) { + if (qemu_lockcnt_dec_if_lock(&ctx->list_lock)) { bhp =3D &ctx->first_bh; while (*bhp) { bh =3D *bhp; @@ -138,7 +138,7 @@ int aio_bh_poll(AioContext *ctx) bhp =3D &bh->next; } } - qemu_lockcnt_unlock(&ctx->list_lock); + qemu_lockcnt_inc_and_unlock(&ctx->list_lock); } return ret; } --=20 2.9.3