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 X-Spam-Level: X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53315C433E2 for ; Tue, 8 Sep 2020 09:19:44 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C04DC21741 for ; Tue, 8 Sep 2020 09:19:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UnhHZP6C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C04DC21741 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37584 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kFZmw-0007np-NH for qemu-devel@archiver.kernel.org; Tue, 08 Sep 2020 05:19:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45206) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kFZlf-0006Nc-95 for qemu-devel@nongnu.org; Tue, 08 Sep 2020 05:18:23 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:50450 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kFZld-0000HV-EE for qemu-devel@nongnu.org; Tue, 08 Sep 2020 05:18:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599556700; h=from:from: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=cRhWHZGMxi7rNLQcj6ZdFavscTq/f5FpHzKS8L8V5Dk=; b=UnhHZP6CGDupV+R0bRrsQfBfxHKQ6+TbI8BPotFe8hjvOcQFXUcd2OseKB4UNYltRC8ey1 S9Jh0S4GF+bDlIUrnoCtc4VI+E/6Duj9toDeEGSJs79ukUeWaAWT7Xjwzu/r+vmMW4fi86 UPVtlAXtE1xAcjCSQ7BpN68mayJIpwA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-434-MccDWk0vOrGu07_Z_2VggQ-1; Tue, 08 Sep 2020 05:18:18 -0400 X-MC-Unique: MccDWk0vOrGu07_Z_2VggQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 62BF7801F9A for ; Tue, 8 Sep 2020 09:18:12 +0000 (UTC) Received: from work-vm (ovpn-114-204.ams2.redhat.com [10.36.114.204]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F270D7ED85; Tue, 8 Sep 2020 09:18:07 +0000 (UTC) Date: Tue, 8 Sep 2020 10:18:05 +0100 From: "Dr. David Alan Gilbert" To: Peter Xu Subject: Re: [PATCH 1/5] migration: Rework migrate_send_rp_req_pages() function Message-ID: <20200908091805.GC3295@work-vm> References: <20200903152646.93336-1-peterx@redhat.com> <20200903152646.93336-2-peterx@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200903152646.93336-2-peterx@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0.003 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/08 02:10:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.1, 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=ham autolearn_force=no X-Spam_action: no action 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: Xiaohui Li , qemu-devel@nongnu.org, Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Peter Xu (peterx@redhat.com) wrote: > We duplicated the logic of maintaining the last_rb variable at both callers of > this function. Pass *rb pointer into the function so that we can avoid > duplicating the logic. Also, when we have the rb pointer, it's also easier to > remove the original 2nd & 4th parameters, because both of them (name of the > ramblock when needed, or the page size) can be fetched from the ramblock > pointer too. > > Signed-off-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert > --- > migration/migration.c | 26 ++++++++++++++++++-------- > migration/migration.h | 4 ++-- > migration/postcopy-ram.c | 24 ++---------------------- > 3 files changed, 22 insertions(+), 32 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index 58a5452471..6761e3f233 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -311,25 +311,35 @@ error: > return ret; > } > > -/* Request a range of pages from the source VM at the given > - * start address. > - * rbname: Name of the RAMBlock to request the page in, if NULL it's the same > - * as the last request (a name must have been given previously) > +/* Request one page from the source VM at the given start address. > + * rb: the RAMBlock to request the page in > * Start: Address offset within the RB > * Len: Length in bytes required - must be a multiple of pagesize > */ > -int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, > - ram_addr_t start, size_t len) > +int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb, > + ram_addr_t start) > { > uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */ > size_t msglen = 12; /* start + len */ > + size_t len = qemu_ram_pagesize(rb); > enum mig_rp_message_type msg_type; > + const char *rbname; > + int rbname_len; > > *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); > *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); > > - if (rbname) { > - int rbname_len = strlen(rbname); > + /* > + * We maintain the last ramblock that we requested for page. Note that we > + * don't need locking because this function will only be called within the > + * postcopy ram fault thread. > + */ > + if (rb != mis->last_rb) { > + mis->last_rb = rb; > + > + rbname = qemu_ram_get_idstr(rb); > + rbname_len = strlen(rbname); > + > assert(rbname_len < 256); > > bufc[msglen++] = rbname_len; > diff --git a/migration/migration.h b/migration/migration.h > index ae497bd45a..ca8dc4c773 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -328,8 +328,8 @@ void migrate_send_rp_shut(MigrationIncomingState *mis, > uint32_t value); > void migrate_send_rp_pong(MigrationIncomingState *mis, > uint32_t value); > -int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname, > - ram_addr_t start, size_t len); > +int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb, > + ram_addr_t start); > void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, > char *block_name); > void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value); > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 1bb22f2b6c..11a70441a6 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -684,14 +684,7 @@ int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb, > qemu_ram_get_idstr(rb), rb_offset); > return postcopy_wake_shared(pcfd, client_addr, rb); > } > - if (rb != mis->last_rb) { > - mis->last_rb = rb; > - migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb), > - aligned_rbo, pagesize); > - } else { > - /* Save some space */ > - migrate_send_rp_req_pages(mis, NULL, aligned_rbo, pagesize); > - } > + migrate_send_rp_req_pages(mis, rb, aligned_rbo); > return 0; > } > > @@ -986,20 +979,7 @@ retry: > * Send the request to the source - we want to request one > * of our host page sizes (which is >= TPS) > */ > - if (rb != mis->last_rb) { > - mis->last_rb = rb; > - ret = migrate_send_rp_req_pages(mis, > - qemu_ram_get_idstr(rb), > - rb_offset, > - qemu_ram_pagesize(rb)); > - } else { > - /* Save some space */ > - ret = migrate_send_rp_req_pages(mis, > - NULL, > - rb_offset, > - qemu_ram_pagesize(rb)); > - } > - > + ret = migrate_send_rp_req_pages(mis, rb, rb_offset); > if (ret) { > /* May be network failure, try to wait for recovery */ > if (ret == -EIO && postcopy_pause_fault_thread(mis)) { > -- > 2.26.2 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK