On Mon, Oct 12, 2020 at 7:57 PM Zengtao (B) <prime.zeng@xxxxxxxxxxxxx> wrote: > > > > -----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 Thanks, so far we only verify it on x86 server, may extend to arm platform in the future.
