On Tue, Jun 13, 2023 at 06:25:48PM +0530, Jay Patel wrote: > > <...snip...> > > > I conducted tests on systems with 160 CPUs and 16 CPUs, using 4K > > > and > > > 64K page sizes. Through these tests, it was observed that the patch > > > successfully reduces the wastage of slab memory without any > > > noticeable > > > performance degradation in the hackbench test report. However, it > > > should > > > be noted that the patch also increases the total number of objects, > > > leading to an overall increase in total slab memory usage. > > > > <...snip...> > > > > Then my question is that, why is this a useful change if total memory > > usage is increased? > > > This patch aimed in reducing memory wastage can potentially lead to an > increase in the slab order for a slab cache. Consequently, this > increase in page order can result in a higher number of objects per > slab, reducing wastage and leading to a more efficient utilization of > memory. if you define utilization as percentage of memory that is being used out of total memory, utilization becomes worse... (based on data you provided) I think 'less memory wastage' is a useful feature only if the total memory usage is reduced so that it could be used for other purposes. I mean, if it consumes more memory on a same workload (in most cases), who would like it? > This enhancement is advantageous since the presence of unused > objects can be leveraged in the future, depending on varying > workloads. At least we need to know when it is leveraged and what kinds of workloads would benefit... Thanks, -- Hyeonggon Yoo Undergraduate | Chungnam National University
