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 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 7B157C25B47 for ; Wed, 25 Oct 2023 09:23:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qva6z-00024T-Lh; Wed, 25 Oct 2023 05:23:37 -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 1qva6s-000205-FI for qemu-devel@nongnu.org; Wed, 25 Oct 2023 05:23:32 -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 1qva6q-0000eL-Ed for qemu-devel@nongnu.org; Wed, 25 Oct 2023 05:23:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698225807; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=a3+Zs8MPib5PI3yOQRaHqAMWdUFbGgWHftPTH8mMLuY=; b=AVcXol2V+SsLh0mdEZd6/Yh/1cwawpmcWwOfV62akBddTprLVvFDktLoW/8/U9X7QgsLUK +CwR9JyjYuiNZjOtT+SQ7JPB/VfHziI/1f9PRUSwtawuwuk/m/1iD+kat5FWAv0N1pk4yC OvvEtFjLEXYtN6xkW11S/fUOLjd8ry8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-402-z_6iYE8CPH6jBPWexsMCxA-1; Wed, 25 Oct 2023 05:23:18 -0400 X-MC-Unique: z_6iYE8CPH6jBPWexsMCxA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6EC65881B6D; Wed, 25 Oct 2023 09:23:18 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 41E4C2026D4C; Wed, 25 Oct 2023 09:23:17 +0000 (UTC) Date: Wed, 25 Oct 2023 10:23:14 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: qemu-devel@nongnu.org, armbru@redhat.com, Juan Quintela , Peter Xu , Leonardo Bras , Claudio Fontana Subject: Re: [PATCH v2 25/29] migration/multifd: Support outgoing fixed-ram stream format Message-ID: References: <20231023203608.26370-1-farosas@suse.de> <20231023203608.26370-26-farosas@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20231023203608.26370-26-farosas@suse.de> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Oct 23, 2023 at 05:36:04PM -0300, Fabiano Rosas wrote: > The new fixed-ram stream format uses a file transport and puts ram > pages in the migration file at their respective offsets and can be > done in parallel by using the pwritev system call which takes iovecs > and an offset. > > Add support to enabling the new format along with multifd to make use > of the threading and page handling already in place. > > This requires multifd to stop sending headers and leaving the stream > format to the fixed-ram code. When it comes time to write the data, we > need to call a version of qio_channel_write that can take an offset. > > Usage on HMP is: > > (qemu) stop > (qemu) migrate_set_capability multifd on > (qemu) migrate_set_capability fixed-ram on > (qemu) migrate_set_parameter max-bandwidth 0 > (qemu) migrate_set_parameter multifd-channels 8 > (qemu) migrate file:migfile > > Signed-off-by: Fabiano Rosas > --- > include/qemu/bitops.h | 13 ++++++++++ > migration/multifd.c | 55 +++++++++++++++++++++++++++++++++++++++++-- > migration/options.c | 6 ----- > migration/ram.c | 2 +- > 4 files changed, 67 insertions(+), 9 deletions(-) > > diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h > index cb3526d1f4..2c0a2fe751 100644 > --- a/include/qemu/bitops.h > +++ b/include/qemu/bitops.h > @@ -67,6 +67,19 @@ static inline void clear_bit(long nr, unsigned long *addr) > *p &= ~mask; > } > > +/** > + * clear_bit_atomic - Clears a bit in memory atomically > + * @nr: Bit to clear > + * @addr: Address to start counting from > + */ > +static inline void clear_bit_atomic(long nr, unsigned long *addr) > +{ > + unsigned long mask = BIT_MASK(nr); > + unsigned long *p = addr + BIT_WORD(nr); > + > + return qatomic_and(p, ~mask); > +} > + > /** > * change_bit - Toggle a bit in memory > * @nr: Bit to change > diff --git a/migration/multifd.c b/migration/multifd.c > index 20e8635740..3f95a41ee9 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -260,6 +260,19 @@ static void multifd_pages_clear(MultiFDPages_t *pages) > g_free(pages); > } > > +static void multifd_set_file_bitmap(MultiFDSendParams *p) > +{ > + MultiFDPages_t *pages = p->pages; > + > + if (!pages->block) { > + return; > + } > + > + for (int i = 0; i < p->normal_num; i++) { > + ramblock_set_shadow_bmap_atomic(pages->block, pages->offset[i]); > + } > +} > + > static void multifd_send_fill_packet(MultiFDSendParams *p) > { > MultiFDPacket_t *packet = p->packet; > @@ -606,6 +619,29 @@ int multifd_send_sync_main(QEMUFile *f) > } > } > > + if (!migrate_multifd_packets()) { > + /* > + * There's no sync packet to send. Just make sure the sending > + * above has finished. > + */ > + for (i = 0; i < migrate_multifd_channels(); i++) { > + qemu_sem_wait(&multifd_send_state->channels_ready); > + } > + > + /* sanity check and release the channels */ > + for (i = 0; i < migrate_multifd_channels(); i++) { > + MultiFDSendParams *p = &multifd_send_state->params[i]; > + > + qemu_mutex_lock(&p->mutex); > + assert(!p->pending_job || p->quit); > + qemu_mutex_unlock(&p->mutex); > + > + qemu_sem_post(&p->sem); > + } > + > + return 0; > + } > + > /* > * When using zero-copy, it's necessary to flush the pages before any of > * the pages can be sent again, so we'll make sure the new version of the > @@ -689,6 +725,8 @@ static void *multifd_send_thread(void *opaque) > > if (p->pending_job) { > uint32_t flags; > + uint64_t write_base; > + > p->normal_num = 0; > > if (!use_packets || use_zero_copy_send) { > @@ -713,6 +751,16 @@ static void *multifd_send_thread(void *opaque) > if (use_packets) { > multifd_send_fill_packet(p); > p->num_packets++; > + write_base = 0; > + } else { > + multifd_set_file_bitmap(p); > + > + /* > + * If we subtract the host page now, we don't need to > + * pass it into qio_channel_write_full_all() below. > + */ > + write_base = p->pages->block->pages_offset - > + (uint64_t)p->pages->block->host; > } > > flags = p->flags; > @@ -738,8 +786,9 @@ static void *multifd_send_thread(void *opaque) > p->iov[0].iov_base = p->packet; > } > > - ret = qio_channel_writev_full_all(p->c, p->iov, p->iovs_num, NULL, > - 0, p->write_flags, &local_err); > + ret = qio_channel_write_full_all(p->c, p->iov, p->iovs_num, > + write_base, NULL, 0, > + p->write_flags, &local_err); > if (ret != 0) { > break; > } > @@ -969,6 +1018,8 @@ int multifd_save_setup(Error **errp) > > if (migrate_zero_copy_send()) { > p->write_flags = QIO_CHANNEL_WRITE_FLAG_ZERO_COPY; > + } else if (!use_packets) { > + p->write_flags |= QIO_CHANNEL_WRITE_FLAG_WITH_OFFSET; > } else { > p->write_flags = 0; > } Ah, so this is why you had the wierd overloaded design for qio_channel_write_full_all in patch 22 that I queried. I'd still prefer the simpler design at the QIO level, and just calling the appropriate function above. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|