From nobody Tue Nov 11 05:01:02 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1563528514; cv=none; d=zoho.com; s=zohoarc; b=FWZlVmFp3+2TQLDgpRwKO8ApJRS5wAl9tdW4vohcygP5bK6hl9D36p1mE09vgRH/yfPGBHcDan2lIX6xjSYjXvw1NDJEUwgutD7iQ9LXdeTE3ViUwtVMPtVAkUwrEH/vof775kT/rbovrvuilGUiisb3PA4ClfNEfdfxu0wqN6c= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1563528514; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=Ew3mW4cFj/dXJHcRYKZwaBamngUG+uNHFRUVkpBtr2M=; b=gHVh3k3rItbMasxn7pXo6wJfCbQ4anpzXYYcTOeNuVhssRXrPT84zZsv6ocMzjGZ21FX+km3FM3HGo8Mwhp9Gk6l95QHQaxtbZr2iehd7EFa87jPYb28JGPKVl6NmnjSYW15JM4TZQwT6oRK7c+oG02teYbAqa7TSZ4jlQKzRzM= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1563528514170419.3534457502906; Fri, 19 Jul 2019 02:28:34 -0700 (PDT) Received: from localhost ([::1]:43368 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoPBo-0001eJ-PI for importer@patchew.org; Fri, 19 Jul 2019 05:28:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37720) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoPA3-0002gV-RB for qemu-devel@nongnu.org; Fri, 19 Jul 2019 05:26:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hoPA2-000608-39 for qemu-devel@nongnu.org; Fri, 19 Jul 2019 05:26:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42112) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hoP9y-0005wv-Ra; Fri, 19 Jul 2019 05:26:39 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2EA7C30C5843; Fri, 19 Jul 2019 09:26:38 +0000 (UTC) Received: from localhost (unknown [10.40.205.128]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 835D261B6A; Fri, 19 Jul 2019 09:26:32 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Fri, 19 Jul 2019 11:26:11 +0200 Message-Id: <20190719092618.24891-4-mreitz@redhat.com> In-Reply-To: <20190719092618.24891-1-mreitz@redhat.com> References: <20190719092618.24891-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 19 Jul 2019 09:26:38 +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 v3 03/10] block: Add @drained_end_counter 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: , Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Callers can now pass a pointer to an integer that bdrv_drain_invoke() (and its recursive callees) will increment for every bdrv_drain_invoke_entry() operation they schedule. bdrv_drain_invoke_entry() in turn will decrement it once it has invoked BlockDriver.bdrv_co_drain_end(). We use atomic operations to access the pointee, because the bdrv_do_drained_end() caller may wish to end drained sections for multiple nodes in different AioContexts (bdrv_drain_all_end() does, for example). This is the first step to moving the polling for BdrvCoDrainData.done to become true out of bdrv_drain_invoke() and into the root drained_end function. Signed-off-by: Max Reitz --- block/io.c | 58 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 18 deletions(-) diff --git a/block/io.c b/block/io.c index 1e618f9a37..c42e18b068 100644 --- a/block/io.c +++ b/block/io.c @@ -194,6 +194,7 @@ typedef struct { bool poll; BdrvChild *parent; bool ignore_bds_parents; + int *drained_end_counter; } BdrvCoDrainData; =20 static void coroutine_fn bdrv_drain_invoke_entry(void *opaque) @@ -211,13 +212,18 @@ static void coroutine_fn bdrv_drain_invoke_entry(void= *opaque) atomic_mb_set(&data->done, true); bdrv_dec_in_flight(bs); =20 - if (data->begin) { + if (data->drained_end_counter) { + atomic_dec(data->drained_end_counter); + } + + if (data->begin || data->drained_end_counter) { g_free(data); } } =20 /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */ -static void bdrv_drain_invoke(BlockDriverState *bs, bool begin) +static void bdrv_drain_invoke(BlockDriverState *bs, bool begin, + int *drained_end_counter) { BdrvCoDrainData *data; =20 @@ -230,16 +236,25 @@ static void bdrv_drain_invoke(BlockDriverState *bs, b= ool begin) *data =3D (BdrvCoDrainData) { .bs =3D bs, .done =3D false, - .begin =3D begin + .begin =3D begin, + .drained_end_counter =3D drained_end_counter, }; =20 + if (!begin && drained_end_counter) { + atomic_inc(drained_end_counter); + } + /* Make sure the driver callback completes during the polling phase for * drain_begin. */ bdrv_inc_in_flight(bs); data->co =3D qemu_coroutine_create(bdrv_drain_invoke_entry, data); aio_co_schedule(bdrv_get_aio_context(bs), data->co); =20 - if (!begin) { + /* + * TODO: Drop this and make callers pass @drained_end_counter and poll + * themselves + */ + if (!begin && !drained_end_counter) { BDRV_POLL_WHILE(bs, !data->done); g_free(data); } @@ -281,7 +296,8 @@ static void bdrv_do_drained_begin(BlockDriverState *bs,= bool recursive, BdrvChild *parent, bool ignore_bds_paren= ts, bool poll); static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, - BdrvChild *parent, bool ignore_bds_parents= ); + BdrvChild *parent, bool ignore_bds_parents, + int *drained_end_counter); =20 static void bdrv_co_drain_bh_cb(void *opaque) { @@ -308,7 +324,8 @@ static void bdrv_co_drain_bh_cb(void *opaque) data->ignore_bds_parents, data->poll); } else { bdrv_do_drained_end(bs, data->recursive, data->parent, - data->ignore_bds_parents); + data->ignore_bds_parents, + data->drained_end_counter); } if (ctx =3D=3D co_ctx) { aio_context_release(ctx); @@ -326,7 +343,8 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDr= iverState *bs, bool begin, bool recursive, BdrvChild *parent, bool ignore_bds_parents, - bool poll) + bool poll, + int *drained_end_counter) { BdrvCoDrainData data; =20 @@ -343,7 +361,9 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDr= iverState *bs, .parent =3D parent, .ignore_bds_parents =3D ignore_bds_parents, .poll =3D poll, + .drained_end_counter =3D drained_end_counter, }; + if (bs) { bdrv_inc_in_flight(bs); } @@ -367,7 +387,7 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, } =20 bdrv_parent_drained_begin(bs, parent, ignore_bds_parents); - bdrv_drain_invoke(bs, true); + bdrv_drain_invoke(bs, true, NULL); } =20 static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, @@ -378,7 +398,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs,= bool recursive, =20 if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_par= ents, - poll); + poll, NULL); return; } =20 @@ -419,20 +439,21 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs) } =20 static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, - BdrvChild *parent, bool ignore_bds_parents) + BdrvChild *parent, bool ignore_bds_parents, + int *drained_end_counter) { BdrvChild *child, *next; int old_quiesce_counter; =20 if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_pa= rents, - false); + false, drained_end_counter); return; } assert(bs->quiesce_counter > 0); =20 /* Re-enable things in child-to-parent order */ - bdrv_drain_invoke(bs, false); + bdrv_drain_invoke(bs, false, drained_end_counter); bdrv_parent_drained_end(bs, parent, ignore_bds_parents); =20 old_quiesce_counter =3D atomic_fetch_dec(&bs->quiesce_counter); @@ -444,19 +465,20 @@ static void bdrv_do_drained_end(BlockDriverState *bs,= bool recursive, assert(!ignore_bds_parents); bs->recursive_quiesce_counter--; QLIST_FOREACH_SAFE(child, &bs->children, next, next) { - bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents= ); + bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents, + drained_end_counter); } } } =20 void bdrv_drained_end(BlockDriverState *bs) { - bdrv_do_drained_end(bs, false, NULL, false); + bdrv_do_drained_end(bs, false, NULL, false, NULL); } =20 void bdrv_subtree_drained_end(BlockDriverState *bs) { - bdrv_do_drained_end(bs, true, NULL, false); + bdrv_do_drained_end(bs, true, NULL, false, NULL); } =20 void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_pare= nt) @@ -473,7 +495,7 @@ void bdrv_unapply_subtree_drain(BdrvChild *child, Block= DriverState *old_parent) int i; =20 for (i =3D 0; i < old_parent->recursive_quiesce_counter; i++) { - bdrv_do_drained_end(child->bs, true, child, false); + bdrv_do_drained_end(child->bs, true, child, false, NULL); } } =20 @@ -543,7 +565,7 @@ void bdrv_drain_all_begin(void) BlockDriverState *bs =3D NULL; =20 if (qemu_in_coroutine()) { - bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true); + bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL); return; } =20 @@ -579,7 +601,7 @@ void bdrv_drain_all_end(void) AioContext *aio_context =3D bdrv_get_aio_context(bs); =20 aio_context_acquire(aio_context); - bdrv_do_drained_end(bs, false, NULL, true); + bdrv_do_drained_end(bs, false, NULL, true, NULL); aio_context_release(aio_context); } =20 --=20 2.21.0