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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]:57024 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kBDKN-0004eU-KB for qemu-devel@archiver.kernel.org; Thu, 27 Aug 2020 04:32:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45596) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kBDJf-00048l-PG for qemu-devel@nongnu.org; Thu, 27 Aug 2020 04:31:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47286) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kBDJc-0005QV-Ch for qemu-devel@nongnu.org; Thu, 27 Aug 2020 04:31:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1598517082; 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=50JwlYsOoKlnXhnX8uabo4g5zjmEMtcgMYx2ZQXTbTE=; b=h5Sb32SmavcDhbX67ShrWXkESDfEAmK8vWDd/B3LksxgKsojNvSYhCyQTG/cJYc4HLific ym31qeXscY6LsHWZadFnee8EqHtwdNa6iBFmf0R2H9phWTS3dCAKTknKMXOEZlFKgvbwmk wvvR2FzXOxZQY75q6c4JUQRxNMqQzGY= 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-16-r8MDsRBHPEax6s7xFz991g-1; Thu, 27 Aug 2020 04:31:20 -0400 X-MC-Unique: r8MDsRBHPEax6s7xFz991g-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7404D1008558; Thu, 27 Aug 2020 08:31:19 +0000 (UTC) Received: from work-vm (ovpn-114-163.ams2.redhat.com [10.36.114.163]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 15A251944D; Thu, 27 Aug 2020 08:31:16 +0000 (UTC) Date: Thu, 27 Aug 2020 09:31:14 +0100 From: "Dr. David Alan Gilbert" To: Zheng Chuan Subject: Re: [PATCH v5 06/12] migration/dirtyrate: Record hash results for each sampled page Message-ID: <20200827083114.GA2837@work-vm> References: <1598319650-36762-1-git-send-email-zhengchuan@huawei.com> <1598319650-36762-7-git-send-email-zhengchuan@huawei.com> <20200826123501.GG2726@work-vm> <3a61c786-ca80-5658-d307-4ae638ad9de0@huawei.com> MIME-Version: 1.0 In-Reply-To: <3a61c786-ca80-5658-d307-4ae638ad9de0@huawei.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/27 02:54:02 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.959, 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_H5=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: berrange@redhat.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, qemu-devel@nongnu.org, xiexiangyou@huawei.com, alex.chen@huawei.com, ann.zhuangyanying@huawei.com, fangying1@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Zheng Chuan (zhengchuan@huawei.com) wrote: > > > On 2020/8/26 20:35, Dr. David Alan Gilbert wrote: > > * Chuan Zheng (zhengchuan@huawei.com) wrote: > >> Record hash results for each sampled page, crc32 is taken to calculate > >> hash results for each sampled 4K-page. > >> > >> Signed-off-by: Chuan Zheng > >> Signed-off-by: YanYing Zhuang > >> --- > >> migration/dirtyrate.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++ > >> migration/dirtyrate.h | 15 ++++++ > >> 2 files changed, 151 insertions(+) > >> > >> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c > >> index f6a94d8..66de426 100644 > >> --- a/migration/dirtyrate.c > >> +++ b/migration/dirtyrate.c > >> @@ -10,6 +10,7 @@ > >> * See the COPYING file in the top-level directory. > >> */ > >> > >> +#include > >> #include "qemu/osdep.h" > >> #include "qapi/error.h" > >> #include "crypto/hash.h" > >> @@ -66,6 +67,141 @@ static void update_dirtyrate(uint64_t msec) > >> DirtyStat.dirty_rate = dirtyrate; > >> } > >> > >> +/* > >> + * get hash result for the sampled memory with length of 4K byte in ramblock, > >> + * which starts from ramblock base address. > >> + */ > >> +static uint32_t get_ramblock_vfn_hash(struct RamblockDirtyInfo *info, > >> + uint64_t vfn) > >> +{ > >> + struct iovec iov_array; > >> + uint32_t crc; > >> + > >> + iov_array.iov_base = info->ramblock_addr + > >> + vfn * DIRTYRATE_SAMPLE_PAGE_SIZE; > >> + iov_array.iov_len = DIRTYRATE_SAMPLE_PAGE_SIZE; > >> + > >> + crc = crc32(0, iov_array.iov_base, iov_array.iov_len); > >> + > >> + return crc; > >> +} > >> + > >> +static int save_ramblock_hash(struct RamblockDirtyInfo *info) > >> +{ > >> + unsigned int sample_pages_count; > >> + int i; > >> + int ret = -1; > >> + GRand *rand = g_rand_new(); > >> + > >> + sample_pages_count = info->sample_pages_count; > >> + > >> + /* ramblock size less than one page, return success to skip this ramblock */ > >> + if (unlikely(info->ramblock_pages == 0 || sample_pages_count == 0)) { > >> + ret = 0; > >> + goto out; > >> + } > >> + > >> + info->hash_result = g_try_malloc0_n(sample_pages_count, > >> + sizeof(uint32_t)); > >> + if (!info->hash_result) { > >> + ret = -1; > >> + goto out; > >> + } > >> + > >> + info->sample_page_vfn = g_try_malloc0_n(sample_pages_count, > >> + sizeof(uint64_t)); > >> + if (!info->sample_page_vfn) { > >> + g_free(info->hash_result); > >> + ret = -1; > >> + goto out; > >> + } > >> + > >> + for (i = 0; i < sample_pages_count; i++) { > >> + info->sample_page_vfn[i] = g_rand_int_range(rand, 0, > >> + info->ramblock_pages - 1); > >> + info->hash_result[i] = get_ramblock_vfn_hash(info, > >> + info->sample_page_vfn[i]); > >> + } > >> + ret = 0; > >> + > >> +out: > >> + g_rand_free(rand); > >> + return ret; > >> +} > >> + > >> +static void get_ramblock_dirty_info(RAMBlock *block, > >> + struct RamblockDirtyInfo *info, > >> + struct DirtyRateConfig *config) > >> +{ > >> + uint64_t sample_pages_per_gigabytes = config->sample_pages_per_gigabytes; > >> + > >> + /* Right shift 30 bits to calc block size in GB */ > >> + info->sample_pages_count = (qemu_ram_get_used_length(block) * > >> + sample_pages_per_gigabytes) >> > >> + DIRTYRATE_PAGE_SHIFT_GB; > >> + > >> + /* Right shift 12 bits to calc page count in 4KB */ > >> + info->ramblock_pages = qemu_ram_get_used_length(block) >> > >> + DIRTYRATE_PAGE_SHIFT_KB; > >> + info->ramblock_addr = qemu_ram_get_host_addr(block); > >> + strcpy(info->idstr, qemu_ram_get_idstr(block)); > >> +} > >> + > >> +static struct RamblockDirtyInfo * > >> +alloc_ramblock_dirty_info(int *block_index, > >> + struct RamblockDirtyInfo *block_dinfo) > >> +{ > >> + struct RamblockDirtyInfo *info = NULL; > >> + int index = *block_index; > >> + > >> + if (!block_dinfo) { > >> + index = 0; > >> + block_dinfo = g_try_new(struct RamblockDirtyInfo, 1); > >> + } else { > >> + index++; > >> + block_dinfo = g_try_realloc(block_dinfo, (index + 1) * > >> + sizeof(struct RamblockDirtyInfo)); > >> + } > >> + if (!block_dinfo) { > >> + return NULL; > >> + } > >> + > >> + info = &block_dinfo[index]; > >> + *block_index = index; > >> + memset(info, 0, sizeof(struct RamblockDirtyInfo)); > >> + > >> + return block_dinfo; > >> +} > >> + > >> +static int record_ramblock_hash_info(struct RamblockDirtyInfo **block_dinfo, > >> + struct DirtyRateConfig config, > >> + int *block_index) > >> +{ > >> + struct RamblockDirtyInfo *info = NULL; > >> + struct RamblockDirtyInfo *dinfo = NULL; > >> + RAMBlock *block = NULL; > >> + int index = 0; > >> + > >> + RAMBLOCK_FOREACH_MIGRATABLE(block) { > >> + dinfo = alloc_ramblock_dirty_info(&index, dinfo); > >> + if (dinfo == NULL) { > >> + return -1; > >> + } > >> + info = &dinfo[index]; > >> + get_ramblock_dirty_info(block, info, &config); > >> + if (save_ramblock_hash(info) < 0) { > >> + *block_dinfo = dinfo; > >> + *block_index = index; > >> + return -1; > >> + } > >> + } > >> + > >> + *block_dinfo = dinfo; > >> + *block_index = index; > >> + > >> + return 0; > >> +} > >> + > >> static void calculate_dirtyrate(struct DirtyRateConfig config) > >> { > >> /* todo */ > >> diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h > >> index 8e25d93..e3adead 100644 > >> --- a/migration/dirtyrate.h > >> +++ b/migration/dirtyrate.h > >> @@ -24,6 +24,21 @@ > >> */ > >> #define RAMBLOCK_INFO_MAX_LEN 256 > >> > >> +/* > >> + * Sample page size 4K as default. > >> + */ > >> +#define DIRTYRATE_SAMPLE_PAGE_SIZE 4096 > >> + > >> +/* > >> + * Sample page size 4K shift > >> + */ > >> +#define DIRTYRATE_PAGE_SHIFT_KB 12 > >> + > >> +/* > >> + * Sample page size 1G shift > >> + */ > >> +#define DIRTYRATE_PAGE_SHIFT_GB 30 > > > > Your naming is really odd here; 'PAGE_SHIFT_KB' divides > > by 4KB, where as 'PAGE_SHIFT_GB' divices by 1KB. > > > > Simplify this; you can just do >>30 for GB because it's well known; > > you don't need a #define constant for simple KB,MB,GB since > > we all know them. > > > Hi, Dave. > Thank you for review. > OK, i will fix that in V6:) > > Also, I've asked before - do you really want 4KB explicitly - or > > should you just use TARGET_PAGE_SIZE and TARGET_PAGE_BITS ? > > > > Dave > > > TARGET_PAGE_SIZE will be 2M or 1G for HugePage. > As you see, what we get is hash result of every 'virtual' 4K-page. > We care about if it is dirty within 4K length in ramblock, which would be more > accurate than TARGET_PAGE_SIZE which could be 2M or 1G. > On the other hand, the hugepage will be broken up into 4K during migration. > > I think it is better we do hash at 'virtual' 4K-page granularity. TARGET_PAGE_SIZE is never 2M or 1G; it's always based on the smallest MMU page on the platform; on x86 it's always 4kB; it's the unit that the migration code works in when dealing with pages. (use TARGET_PAGE_BITS to shift by). Dave > >> + > >> /* Take 1s as default for calculation duration */ > >> #define DEFAULT_FETCH_DIRTYRATE_TIME_SEC 1 > >> > >> -- > >> 1.8.3.1 > >> > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK