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 4AB96C0032E for ; Wed, 25 Oct 2023 14:22:24 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qvelk-0002x5-0W; Wed, 25 Oct 2023 10:22:00 -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 1qvele-0002ua-EI for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:21:56 -0400 Received: from smtp-out2.suse.de ([2001:67c:2178:6::1d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qvela-0001Yb-AZ for qemu-devel@nongnu.org; Wed, 25 Oct 2023 10:21:53 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id D26471FF65; Wed, 25 Oct 2023 14:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1698243703; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vC5GX6ObTzx39u+URDw80MEIvdKnYFDiljcwBcmK9bI=; b=OSehQ7mg/Li6F3oQYq8YkDSQbI+wYDXCBQk/+lyZN8Ln+05dX5qWYbtmOLrUyKzKPx1BDx T63s+5s5efymY3u3iimkZ+yU/dPGwMUt7S9Zo3e9NL8GsI1E5De6HHF/eYjaLMSAHIf7H8 Jq+MW3ryhoSgfGPw6CuYiSy6mP92HOg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1698243703; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vC5GX6ObTzx39u+URDw80MEIvdKnYFDiljcwBcmK9bI=; b=f63pOPObm58fsHNe4oXf6lxCEMtVh6K6z1lL+Fr42RgJpwfqB21q05X1FLmAkfkjvYnFN2 VlFpG8BCuJ9fpNBQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 6210B138E9; Wed, 25 Oct 2023 14:21:43 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id rXS3C3ckOWXOGgAAMHmgww (envelope-from ); Wed, 25 Oct 2023 14:21:43 +0000 From: Fabiano Rosas To: =?utf-8?Q?Daniel_P=2E_Berrang=C3=A9?= 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 In-Reply-To: References: <20231023203608.26370-1-farosas@suse.de> <20231023203608.26370-26-farosas@suse.de> Date: Wed, 25 Oct 2023 11:21:41 -0300 Message-ID: <87h6meeqa2.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [-7.10 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; BAYES_HAM(-3.00)[100.00%]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-3.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RCPT_COUNT_SEVEN(0.00)[7]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[] Received-SPF: pass client-ip=2001:67c:2178:6::1d; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Daniel P. Berrang=C3=A9 writes: > 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. >>=20 >> Add support to enabling the new format along with multifd to make use >> of the threading and page handling already in place. >>=20 >> 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. >>=20 >> Usage on HMP is: >>=20 >> (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 >>=20 >> 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(-) >>=20 >> 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 &=3D ~mask; >> } >>=20=20 >> +/** >> + * 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 =3D BIT_MASK(nr); >> + unsigned long *p =3D 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 *pag= es) >> g_free(pages); >> } >>=20=20 >> +static void multifd_set_file_bitmap(MultiFDSendParams *p) >> +{ >> + MultiFDPages_t *pages =3D p->pages; >> + >> + if (!pages->block) { >> + return; >> + } >> + >> + for (int i =3D 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 =3D p->packet; >> @@ -606,6 +619,29 @@ int multifd_send_sync_main(QEMUFile *f) >> } >> } >>=20=20 >> + if (!migrate_multifd_packets()) { >> + /* >> + * There's no sync packet to send. Just make sure the sending >> + * above has finished. >> + */ >> + for (i =3D 0; i < migrate_multifd_channels(); i++) { >> + qemu_sem_wait(&multifd_send_state->channels_ready); >> + } >> + >> + /* sanity check and release the channels */ >> + for (i =3D 0; i < migrate_multifd_channels(); i++) { >> + MultiFDSendParams *p =3D &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 a= ny 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) >>=20=20 >> if (p->pending_job) { >> uint32_t flags; >> + uint64_t write_base; >> + >> p->normal_num =3D 0; >>=20=20 >> 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 =3D 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 =3D p->pages->block->pages_offset - >> + (uint64_t)p->pages->block->host; >> } >>=20=20 >> flags =3D p->flags; >> @@ -738,8 +786,9 @@ static void *multifd_send_thread(void *opaque) >> p->iov[0].iov_base =3D p->packet; >> } >>=20=20 >> - ret =3D qio_channel_writev_full_all(p->c, p->iov, p->iovs_n= um, NULL, >> - 0, p->write_flags, &local= _err); >> + ret =3D qio_channel_write_full_all(p->c, p->iov, p->iovs_nu= m, >> + write_base, NULL, 0, >> + p->write_flags, &local_err= ); >> if (ret !=3D 0) { >> break; >> } >> @@ -969,6 +1018,8 @@ int multifd_save_setup(Error **errp) >>=20=20 >> if (migrate_zero_copy_send()) { >> p->write_flags =3D QIO_CHANNEL_WRITE_FLAG_ZERO_COPY; >> + } else if (!use_packets) { >> + p->write_flags |=3D QIO_CHANNEL_WRITE_FLAG_WITH_OFFSET; >> } else { >> p->write_flags =3D 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.=20 Yes, I didn't want to have multifd choosing between different IO functions during (multifd) runtime. Here we set the flag at setup time and forget about it. I now understand multifd a bit more so I'm more confident changing the code, let's see how your suggestion looks like. > > With regards, > Daniel