From patchwork Tue Mar 11 16:00:05 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 14012245 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 A6296C282EC for ; Tue, 11 Mar 2025 16:07:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ts27K-0000yC-N4; Tue, 11 Mar 2025 12:06:08 -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 1ts22B-00041a-Ia for qemu-devel@nongnu.org; Tue, 11 Mar 2025 12:00:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ts226-0005hj-JQ for qemu-devel@nongnu.org; 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Tue, 11 Mar 2025 16:00:38 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.44.33.18]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D788F1800373; Tue, 11 Mar 2025 16:00:36 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 06/22] aio-posix: Factor out adjust_polling_time() Date: Tue, 11 Mar 2025 17:00:05 +0100 Message-ID: <20250311160021.349761-7-kwolf@redhat.com> In-Reply-To: <20250311160021.349761-1-kwolf@redhat.com> References: <20250311160021.349761-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=0.01 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org Signed-off-by: Kevin Wolf Message-ID: <20250307221634.71951-5-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- util/aio-posix.c | 77 ++++++++++++++++++++++++++---------------------- 1 file changed, 41 insertions(+), 36 deletions(-) diff --git a/util/aio-posix.c b/util/aio-posix.c index 95bddb9e4b..259827c7ad 100644 --- a/util/aio-posix.c +++ b/util/aio-posix.c @@ -600,6 +600,46 @@ static bool try_poll_mode(AioContext *ctx, AioHandlerList *ready_list, return false; } +static void adjust_polling_time(AioContext *ctx, AioPolledEvent *poll, + int64_t block_ns) +{ + if (block_ns <= poll->ns) { + /* This is the sweet spot, no adjustment needed */ + } else if (block_ns > ctx->poll_max_ns) { + /* We'd have to poll for too long, poll less */ + int64_t old = poll->ns; + + if (ctx->poll_shrink) { + poll->ns /= ctx->poll_shrink; + } else { + poll->ns = 0; + } + + trace_poll_shrink(ctx, old, poll->ns); + } else if (poll->ns < ctx->poll_max_ns && + block_ns < ctx->poll_max_ns) { + /* There is room to grow, poll longer */ + int64_t old = poll->ns; + int64_t grow = ctx->poll_grow; + + if (grow == 0) { + grow = 2; + } + + if (poll->ns) { + poll->ns *= grow; + } else { + poll->ns = 4000; /* start polling at 4 microseconds */ + } + + if (poll->ns > ctx->poll_max_ns) { + poll->ns = ctx->poll_max_ns; + } + + trace_poll_grow(ctx, old, poll->ns); + } +} + bool aio_poll(AioContext *ctx, bool blocking) { AioHandlerList ready_list = QLIST_HEAD_INITIALIZER(ready_list); @@ -682,42 +722,7 @@ bool aio_poll(AioContext *ctx, bool blocking) /* Adjust polling time */ if (ctx->poll_max_ns) { int64_t block_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - start; - - if (block_ns <= ctx->poll.ns) { - /* This is the sweet spot, no adjustment needed */ - } else if (block_ns > ctx->poll_max_ns) { - /* We'd have to poll for too long, poll less */ - int64_t old = ctx->poll.ns; - - if (ctx->poll_shrink) { - ctx->poll.ns /= ctx->poll_shrink; - } else { - ctx->poll.ns = 0; - } - - trace_poll_shrink(ctx, old, ctx->poll.ns); - } else if (ctx->poll.ns < ctx->poll_max_ns && - block_ns < ctx->poll_max_ns) { - /* There is room to grow, poll longer */ - int64_t old = ctx->poll.ns; - int64_t grow = ctx->poll_grow; - - if (grow == 0) { - grow = 2; - } - - if (ctx->poll.ns) { - ctx->poll.ns *= grow; - } else { - ctx->poll.ns = 4000; /* start polling at 4 microseconds */ - } - - if (ctx->poll.ns > ctx->poll_max_ns) { - ctx->poll.ns = ctx->poll_max_ns; - } - - trace_poll_grow(ctx, old, ctx->poll.ns); - } + adjust_polling_time(ctx, &ctx->poll, block_ns); } progress |= aio_bh_poll(ctx);