From patchwork Tue Oct 25 08:49:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1694324 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Q+Whu1bD; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MxR814P1Lz23lH for ; Tue, 25 Oct 2022 20:13:53 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1onFmA-0004F5-V5; Tue, 25 Oct 2022 04:59:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1onFdW-0007Xo-0G for qemu-devel@nongnu.org; Tue, 25 Oct 2022 04:50:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1onFdL-0007Vq-7T for qemu-devel@nongnu.org; Tue, 25 Oct 2022 04:50:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666687802; 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=WMPMKxRdFZc5XVi8BCyru4Ab+xE+tdDqXkClIl0h75E=; b=Q+Whu1bDtmHo3l1X1p6Fq2yg2q0k5w8lPUyuLUK4oHw8G8Cn14C8zxx1ClYDYI0mlAJMsN ll7aUmNCPGrG5xGj/zTqyKtfPzNrYT/YGNh0j583sW8eWTiYBvOVqj/IfF/YZB6fKJ5H/M 9kwwg3gqYeT+VYVE/+0ATL53uCT4uS0= 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-613-wY3N2oL0MG--Ks5c6V9PUQ-1; Tue, 25 Oct 2022 04:49:55 -0400 X-MC-Unique: wY3N2oL0MG--Ks5c6V9PUQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 64A30858F13; Tue, 25 Oct 2022 08:49:55 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1F88935429; Tue, 25 Oct 2022 08:49:55 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Cc: Kevin Wolf , Hanna Reitz , Paolo Bonzini , John Snow , Vladimir Sementsov-Ogievskiy , Markus Armbruster , Stefan Hajnoczi , qemu-devel@nongnu.org, Emanuele Giuseppe Esposito Subject: [PATCH v3 03/10] bdrv_change_aio_context: use hash table instead of list of visited nodes Date: Tue, 25 Oct 2022 04:49:45 -0400 Message-Id: <20221025084952.2139888-4-eesposit@redhat.com> In-Reply-To: <20221025084952.2139888-1-eesposit@redhat.com> References: <20221025084952.2139888-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.503, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Minor performance improvement, but given that we have hash tables available, avoid iterating in the visited nodes list every time just to check if a node has been already visited. The data structure is not actually a proper hash map, but an hash set, as we are just adding nodes and not key,value pairs. Suggested-by: Hanna Reitz Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Kevin Wolf --- block.c | 28 ++++++++++++++++------------ include/block/block-global-state.h | 2 +- include/block/block_int-common.h | 3 ++- 3 files changed, 19 insertions(+), 14 deletions(-) diff --git a/block.c b/block.c index 4da7526674..56c57d07fa 100644 --- a/block.c +++ b/block.c @@ -105,7 +105,7 @@ static void bdrv_reopen_abort(BDRVReopenState *reopen_state); static bool bdrv_backing_overridden(BlockDriverState *bs); static bool bdrv_change_aio_context(BlockDriverState *bs, AioContext *ctx, - GSList **visited, Transaction *tran, + GHashTable *visited, Transaction *tran, Error **errp); /* If non-zero, use only whitelisted block drivers */ @@ -7315,14 +7315,15 @@ typedef struct BdrvStateSetAioContext { } BdrvStateSetAioContext; static bool bdrv_parent_change_aio_context(BdrvChild *c, AioContext *ctx, - GSList **visited, Transaction *tran, + GHashTable *visited, + Transaction *tran, Error **errp) { GLOBAL_STATE_CODE(); - if (g_slist_find(*visited, c)) { + if (g_hash_table_contains(visited, c)) { return true; } - *visited = g_slist_prepend(*visited, c); + g_hash_table_add(visited, c); /* * A BdrvChildClass that doesn't handle AioContext changes cannot @@ -7353,14 +7354,14 @@ bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx, } bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx, - GSList **visited, Transaction *tran, + GHashTable *visited, Transaction *tran, Error **errp) { GLOBAL_STATE_CODE(); - if (g_slist_find(*visited, c)) { + if (g_hash_table_contains(visited, c)) { return true; } - *visited = g_slist_prepend(*visited, c); + g_hash_table_add(visited, c); return bdrv_change_aio_context(c->bs, ctx, visited, tran, errp); } @@ -7445,7 +7446,7 @@ static TransactionActionDrv set_aio_context = { * responsible for freeing the list afterwards. */ static bool bdrv_change_aio_context(BlockDriverState *bs, AioContext *ctx, - GSList **visited, Transaction *tran, + GHashTable *visited, Transaction *tran, Error **errp) { BdrvChild *c; @@ -7524,7 +7525,7 @@ int bdrv_child_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, BdrvChild *ignore_child, Error **errp) { Transaction *tran; - GSList *visited; + GHashTable *visited; int ret; AioContext *old_context = bdrv_get_aio_context(bs); GLOBAL_STATE_CODE(); @@ -7536,9 +7537,12 @@ int bdrv_child_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, * is successful (the transaction itself). */ tran = tran_new(); - visited = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL; - ret = bdrv_change_aio_context(bs, ctx, &visited, tran, errp); - g_slist_free(visited); + visited = g_hash_table_new(NULL, NULL); + if (ignore_child) { + g_hash_table_add(visited, ignore_child); + } + ret = bdrv_change_aio_context(bs, ctx, visited, tran, errp); + g_hash_table_destroy(visited); /* * Linear phase: go through all callbacks collected in the transaction. diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index 7b0095b419..e7372ec541 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -233,7 +233,7 @@ bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx, AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c); bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx, - GSList **visited, Transaction *tran, + GHashTable *visited, Transaction *tran, Error **errp); int bdrv_child_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, BdrvChild *ignore_child, Error **errp); diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 9067a99249..7ccbbdae05 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -911,7 +911,8 @@ struct BdrvChildClass { void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore); bool (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, - GSList **visited, Transaction *tran, Error **errp); + GHashTable *visited, Transaction *tran, + Error **errp); AioContext *(*get_parent_aio_context)(BdrvChild *child);