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Wysocki" References: <20220830081736.119281-1-aneesh.kumar@linux.ibm.com> <87tu5rzigc.fsf@yhuang6-desk2.ccr.corp.intel.com> <87pmgezkhp.fsf@yhuang6-desk2.ccr.corp.intel.com> <87fshaz63h.fsf@yhuang6-desk2.ccr.corp.intel.com> <698120ce-d4df-3d13-dea9-a8f5c298783c@linux.ibm.com> <87bkryz4nh.fsf@yhuang6-desk2.ccr.corp.intel.com> <2b4ddc45-74ae-27df-d973-6724f61f4e18@linux.ibm.com> <877d2mz3c1.fsf@yhuang6-desk2.ccr.corp.intel.com> From: Aneesh Kumar K V In-Reply-To: <877d2mz3c1.fsf@yhuang6-desk2.ccr.corp.intel.com> Content-Type: text/plain; charset=UTF-8 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: id3h1xHQI30Uq9IFIfXdbOVYH4Nu8qtS X-Proofpoint-GUID: Vy__WMwFUcpmib_RCUdVcQyq-Vg3vas3 Content-Transfer-Encoding: 7bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-09-01_12,2022-08-31_03,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 malwarescore=0 lowpriorityscore=0 suspectscore=0 impostorscore=0 clxscore=1015 phishscore=0 mlxscore=0 bulkscore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2209020029 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662101094; h=from:from:sender:reply-to:subject:subject: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:dkim-signature; bh=oXfhblV9Gn509Y6lsGhV9mLyu7HT0FI0E4q3AT34Jts=; b=74S55vLV0ukD9Y5KVPPQdvFsXj/eKploYEYoXC76ZvdDXiiJhvSJkrbbfp0fG+4efOAl2W BnDpyY7WkirZSViQK0PyBaOF8RpNwkwYahTsi6iXtSMP5Brt0DIvjVfijdtYKw4eZR+BaL H/0cd++Ee4KekH8KqjuyRkQ+iwO2QuE= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=r2je0uCU; spf=pass (imf25.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662101094; a=rsa-sha256; cv=none; b=tLJoqojF2zwHZSw848tG3gp2iqE1bd1Qwcd6DJf6hV7y6u5ZX4aZI7dkW1+FGvWube8S0W z2GfWpO1IJkpl9sLvOZVRkoWeLfF80huwUdW4e8S+AUrb2igS7iXOXwSLYMZbcX5+BVfrG 8I7qYKoi8hYad8HTqLJ/W7g/gPVbtTA= Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=r2je0uCU; spf=pass (imf25.hostedemail.com: domain of aneesh.kumar@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=aneesh.kumar@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com X-Rspamd-Server: rspam11 X-Stat-Signature: o859ytccjph7zee7e3fp8sonjgs51ggj X-Rspamd-Queue-Id: 6DDCFA0061 X-Rspam-User: X-HE-Tag: 1662101094-83889 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 9/2/22 12:10 PM, Huang, Ying wrote: > Aneesh Kumar K V writes: > >> On 9/2/22 11:42 AM, Huang, Ying wrote: >>> Aneesh Kumar K V writes: >>> >>>> On 9/2/22 11:10 AM, Huang, Ying wrote: >>>>> Aneesh Kumar K V writes: >>>>> >>>>>> On 9/2/22 10:39 AM, Wei Xu wrote: >>>>>>> On Thu, Sep 1, 2022 at 5:33 PM Huang, Ying wrote: >>>>>>>> >>>>>>>> Aneesh Kumar K V writes: >>>>>>>> >>>>>>>>> On 9/1/22 12:31 PM, Huang, Ying wrote: >>>>>>>>>> "Aneesh Kumar K.V" writes: >>>>>>>>>> >>>>>>>>>>> This patch adds /sys/devices/virtual/memory_tiering/ where all memory tier >>>>>>>>>>> related details can be found. All allocated memory tiers will be listed >>>>>>>>>>> there as /sys/devices/virtual/memory_tiering/memory_tierN/ >>>>>>>>>>> >>>>>>>>>>> The nodes which are part of a specific memory tier can be listed via >>>>>>>>>>> /sys/devices/virtual/memory_tiering/memory_tierN/nodes >>>>>>>>>> >>>>>>>>>> I think "memory_tier" is a better subsystem/bus name than >>>>>>>>>> memory_tiering. Because we have a set of memory_tierN devices inside. >>>>>>>>>> "memory_tier" sounds more natural. I know this is subjective, just my >>>>>>>>>> preference. >>>>>>>>>> >>>>>> >>>>>> >>>>>> I missed replying to this earlier. I will keep memory_tiering as subsystem name in v4 >>>>>> because we would want it to a susbsystem where all memory tiering related details can be found >>>>>> including memory type in the future. This is as per discussion >>>>>> >>>>>> https://lore.kernel.org/linux-mm/CAAPL-u9TKbHGztAF=r-io3gkX7gorUunS2UfstudCWuihrA=0g@mail.gmail.com >>>>> >>>>> I don't think that it's a good idea to mix 2 types of devices in one >>>>> subsystem (bus). If my understanding were correct, that breaks the >>>>> driver core convention. >>>>> >>>> >>>> All these are virtual devices .I am not sure i follow what you mean by 2 types of devices. >>>> memory_tiering is a subsystem that represents all the details w.r.t memory tiering. It shows >>>> details of memory tiers and can possibly contain details of different memory types . >>> >>> IMHO, memory_tier and memory_type are 2 kind of devices. They have >>> almost totally different attributes (sysfs file). So, we should create >>> 2 buses for them. Each has its own attribute group. "virtual" itself >>> isn't a subsystem. >> >> Considering both the details are related to memory tiering, wouldn't it be much simpler we consolidate >> them within the same subdirectory? I am still not clear why you are suggesting they need to be in different >> sysfs hierarchy. It doesn't break any driver core convention as you mentioned earlier. >> >> /sys/devices/virtual/memory_tiering/memory_tierN >> /sys/devices/virtual/memory_tiering/memory_typeN > > I think we should add > > /sys/devices/virtual/memory_tier/memory_tierN > /sys/devices/virtual/memory_type/memory_typeN > I am trying to find if there is a technical reason to do the same? > I don't think this is complex. Devices of same bus/subsystem should > have mostly same attributes. This is my understanding of driver core > convention. > I was not looking at this from code complexity point. Instead of having multiple directories with details w.r.t memory tiering, I was looking at consolidating the details within the directory /sys/devices/virtual/memory_tiering. (similar to all virtual devices are consolidated within /sys/devics/virtual/). -aneesh