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 3459EC30653 for ; Sun, 7 Jul 2024 03:57:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sQJ0M-00078G-Ld; Sat, 06 Jul 2024 23:56:02 -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 1sQJ0J-00077P-ND for qemu-devel@nongnu.org; Sat, 06 Jul 2024 23:55:59 -0400 Received: from smtpnm6-01.21cn.com ([182.42.159.233] helo=chinatelecom.cn) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sQJ04-00058b-5n for qemu-devel@nongnu.org; Sat, 06 Jul 2024 23:55:59 -0400 HMM_SOURCE_IP: 192.168.137.232:0.1157604967 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-112.44.131.222 (unknown [192.168.137.232]) by chinatelecom.cn (HERMES) with SMTP id 0D511100105AC; Sun, 7 Jul 2024 11:48:05 +0800 (CST) X-189-SAVE-TO-SEND: +tugy@chinatelecom.cn Received: from ([112.44.131.222]) by gateway-ssl-dep-67bdc54df-b7md5 with ESMTP id 1a1a4769622d46b38aff24ffb226bbc9 for dave@treblig.org; Sun, 07 Jul 2024 11:48:13 CST X-Transaction-ID: 1a1a4769622d46b38aff24ffb226bbc9 X-Real-From: tugy@chinatelecom.cn X-Receive-IP: 112.44.131.222 X-MEDUSA-Status: 0 Message-ID: <1cdea76d-cac1-4060-9f8e-7bb7a1f37432@chinatelecom.cn> Date: Sun, 7 Jul 2024 11:48:03 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: tugy@chinatelecom.cn, qemu-devel@nongnu.org, dengpc12@chinatelecom.cn, zhangl161@chinatelecom.cn Subject: Re: [PATCH] misc: introduce strim-memory qapi to support free memory trimming To: "Dr. David Alan Gilbert" , Markus Armbruster , Eric Blake References: <0370576b-0660-4fb0-ac70-5b31ad6e3dbf@chinatelecom.cn> Content-Language: en-US From: Guoyi Tu In-Reply-To: <0370576b-0660-4fb0-ac70-5b31ad6e3dbf@chinatelecom.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=182.42.159.233; envelope-from=tugy@chinatelecom.cn; helo=chinatelecom.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-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 Hi there, please review this patch，any comments are welcome. On 2024/6/28 18:22, Guoyi Tu wrote: > In the test environment, we conducted IO stress tests on all storage disks > within a virtual machine that had five storage devices mounted.During > testing, > we found that the qemu process allocated a large amount of memory (~800MB) > to handle these IO operations. > > When the test ended, although qemu called free() to release the allocated > memory, the memory was not actually returned to the operating system, as > observed via the top command. > > Upon researching the glibc memory management mechanism, we found that when > small chunks of memory are allocated in user space and then released with > free(),  the glibc memory management mechanism does not necessarily return > this memory to the operating system. Instead, it retains the memory until > certain conditions are met for release. > > For virtual machines that only have business operations during specific > periods,  they remain idle most of the time. However, the qemu process > still occupies a large amount of memory resources, leading to significant > memory resource waste. > > To address this issue, this patch introduces an API to actively reclaim > idle memory within the qemu process. This API effectively calls > malloc_trim() > to notify glibc to trim free memory. With this api, the management tool > can monitor the virtual machine's state and call this API during idle times > to free up the memory occupied by the virtual machine, thereby allowing > more > virtual machines to be provisioned. > > Signed-off-by: Guoyi Tu > Signed-off-by: dengpengcheng > --- >  hmp-commands.hx       | 13 +++++++++++++ >  include/monitor/hmp.h |  1 + >  monitor/hmp-cmds.c    | 14 ++++++++++++++ >  monitor/qmp-cmds.c    | 18 ++++++++++++++++++ >  qapi/misc.json        | 13 +++++++++++++ >  5 files changed, 59 insertions(+) > > diff --git a/hmp-commands.hx b/hmp-commands.hx > index 06746f0afc..0fde22fc71 100644 > --- a/hmp-commands.hx > +++ b/hmp-commands.hx > @@ -1858,4 +1858,17 @@ SRST >  ``xen-event-list`` >    List event channels in the guest >  ERST > + > +    { > +        .name       = "trim-memory", > +        .args_type  = "reserved:l?", > +        .params     = "[reserved]", > +        .help       = "trim momory", > +        .cmd        = hmp_trim_memory, > +    }, > + > +SRST > +``trim-memory`` *reserved* > +  try to release free memory and keep reserved bytes of free memory > untrimmed > +ERST >  #endif > diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h > index 954f3c83ad..547cde0056 100644 > --- a/include/monitor/hmp.h > +++ b/include/monitor/hmp.h > @@ -181,5 +181,6 @@ void hmp_boot_set(Monitor *mon, const QDict *qdict); >  void hmp_info_mtree(Monitor *mon, const QDict *qdict); >  void hmp_info_cryptodev(Monitor *mon, const QDict *qdict); >  void hmp_dumpdtb(Monitor *mon, const QDict *qdict); > +void hmp_trim_memory(Monitor *mon, const QDict *qdict); > >  #endif > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c > index ea79148ee8..f842e43315 100644 > --- a/monitor/hmp-cmds.c > +++ b/monitor/hmp-cmds.c > @@ -460,3 +460,17 @@ void hmp_dumpdtb(Monitor *mon, const QDict *qdict) >      monitor_printf(mon, "dtb dumped to %s", filename); >  } >  #endif > + > +void hmp_trim_memory(Monitor *mon, const QDict *qdict) > +{ > +    int64_t reserved; > +    bool has_reserved = qdict_haskey(qdict, "reserved"); > +    Error *err = NULL; > + > +    if (has_reserved) { > +        reserved = qdict_get_int(qdict, "reserved"); > +    } > + > +    qmp_trim_memory(has_reserved, reserved, &err); > +    hmp_handle_error(mon, err); > +} > diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c > index f84a0dc523..878a7a646a 100644 > --- a/monitor/qmp-cmds.c > +++ b/monitor/qmp-cmds.c > @@ -31,6 +31,7 @@ >  #include "qapi/type-helpers.h" >  #include "hw/mem/memory-device.h" >  #include "hw/intc/intc.h" > +#include > >  NameInfo *qmp_query_name(Error **errp) >  { > @@ -161,6 +162,23 @@ void qmp_add_client(const char *protocol, const > char *fdname, >      } >  } > > +void qmp_trim_memory(bool has_reserved, int64_t reserved, Error **errp) > +{ > +#if defined(CONFIG_MALLOC_TRIM) > +    if (!has_reserved) { > +        reserved = 1024 * 1024; > +    } > +    if (reserved < 0) { > +        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, > +                   "reserved", "a >0 reserved"); > +        return; > +    } > +    malloc_trim(reserved); > +#else > +    error_setg(errp, "malloc_trim feature not configured"); > +#endif > +} > + >  char *qmp_human_monitor_command(const char *command_line, bool > has_cpu_index, >                                  int64_t cpu_index, Error **errp) >  { > diff --git a/qapi/misc.json b/qapi/misc.json > index ec30e5c570..00e6f2f650 100644 > --- a/qapi/misc.json > +++ b/qapi/misc.json > @@ -605,3 +605,16 @@ >  { 'event': 'VFU_CLIENT_HANGUP', >    'data': { 'vfu-id': 'str', 'vfu-qom-path': 'str', >              'dev-id': 'str', 'dev-qom-path': 'str' } } > + > +## > +# @trim-memory: > +# > +# try to release free memory > +# > +# @reserved: specifies the amount of free space to leave untrimmed. > +#            default to 1MB if not specified. > +# > +# Since: 9.0 > +## > +{'command': 'trim-memory', > + 'data': {'*reserved': 'int'} } -- 涂国义 云网产品事业部-弹性计算-G1组-虚拟化 18030537745 成都市武侯区益州大道1666号中国电信西部信息中心