> -----Original Message----- > From: yulei.kernel@xxxxxxxxx [mailto:yulei.kernel@xxxxxxxxx] > Sent: Thursday, October 08, 2020 3:54 PM > To: akpm@xxxxxxxxxxxxxxxxxxxx; naoya.horiguchi@xxxxxxx; > viro@xxxxxxxxxxxxxxxxxx; pbonzini@xxxxxxxxxx > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; xiaoguangrong.eric@xxxxxxxxx; > kernellwp@xxxxxxxxx; lihaiwei.kernel@xxxxxxxxx; Yulei Zhang > Subject: [PATCH 00/35] Enhance memory utilization with DMEMFS > > From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx> > > In current system each physical memory page is assocaited with > a page structure which is used to track the usage of this page. > But due to the memory usage rapidly growing in cloud environment, > we find the resource consuming for page structure storage becomes > highly remarkable. So is it an expense that we could spare? > > This patchset introduces an idea about how to save the extra > memory through a new virtual filesystem -- dmemfs. > > Dmemfs (Direct Memory filesystem) is device memory or reserved > memory based filesystem. This kind of memory is special as it > is not managed by kernel and most important it is without 'struct page'. > Therefore we can leverage the extra memory from the host system > to support more tenants in our cloud service. > > We uses a kernel boot parameter 'dmem=' to reserve the system > memory when the host system boots up, the details can be checked > in /Documentation/admin-guide/kernel-parameters.txt. > > Theoretically for each 4k physical page it can save 64 bytes if > we drop the 'struct page', so for guest memory with 320G it can > save about 5G physical memory totally. Sounds interesting, but seems your patch only support x86, have you considered aarch64? Regards Zengtao
