Might be worth looking into GOMEMLIMIT. ________________________________ From: golang-nuts@googlegroups.com <golang-nuts@googlegroups.com> on behalf of Zhihui Jiang <coboy123...@gmail.com> Sent: Monday, December 4, 2023 10:05:52 PM To: golang-nuts <golang-nuts@googlegroups.com> Subject: [go-nuts] Low memory utilization when using soft memory limit with GOGC=off
Hi there, We are running a large scale recommendation system using Golang and we are working on some GC related improvement recently. One of the changes we are trying to apply is to use soft memory limit with GOGC=off as suggested here: https://github.com/golang/go/issues/48409. But during our testing, the memory usage never reaches the memory limit we set. For example, we have 100GB memory available and we set the memory limit to 90GB, but the actual memory usage is very low like <50GB. We also observed the GC is actually very frequent which cost a lot of CPU time. We had another tweak to set GOGC to a high value like 200, and the memory usage is quite close to the memory limit. I have two questions here: 1. Is it expected behavior that the memory usage is much lower than memory limit when GOGC is set to off? From the official doc (https://github.com/golang/go/issues/48409), it claims " by setting GOGC=off, the Go runtime will always grow the heap to the full memory limit"? 2. How is the GC frequency decided when using soft memory limit + GOGC=off? Is there some internal defalut value for GOGC in this case to decide when to GC? Thanks! -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com<mailto:golang-nuts+unsubscr...@googlegroups.com>. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/81d76570-9c09-4583-b900-fcfd19023f28n%40googlegroups.com<https://groups.google.com/d/msgid/golang-nuts/81d76570-9c09-4583-b900-fcfd19023f28n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/SJ0PR07MB9795F678F54415A639E77C32A085A%40SJ0PR07MB9795.namprd07.prod.outlook.com.
