08/11/2024 23:34, Mattias Rönnblom: > On 2024-11-08 23:13, Thomas Monjalon wrote: > > 08/11/2024 20:53, Morten Brørup: > >>> From: Morten Brørup [mailto:m...@smartsharesystems.com] > >>> Sent: Friday, 8 November 2024 19.35 > >>> > >>>> From: David Marchand [mailto:david.march...@redhat.com] > >>>> Sent: Friday, 8 November 2024 19.18 > >>>> > >>>> OVS locks all pages to avoid page faults while processing packets. > >> > >> It sounds smart, so I just took a look at how it does this. I'm not sure, > >> but it seems like it only locks pages that are actually mapped (current > >> and future). > >> > >>>> 1M for each lcore translates to allocating 128M with default build > >>>> options on x86. > >>>> This resulted in OOM while running unit tests in parallel. > >> > >> Is the root cause the lcore variables library itself, or the unit test > >> using a lot of memory for testing the lcore variables? > >> We don't want to fix the library if the problem is elsewhere. > > > > The fix works for our urgent issue and we want to make a release candidate > > soon. > > > > > >>>> At the moment, the more demanding DPDK user of lcore variable is > >>>> rte_service, with a 2112 bytes object. > >>>> > >>>> Limit the lcore variable maximum size to 4k which looks more > >>>> reasonable. > >>> > >>> 4 KB is not future proof. > >>> > >>> Here's an example where 16 KB is cutting it close: > >>> https://inbox.dpdk.org/dev/98CBD80474FA8B44BF855DF32C47DC35E9F7D0@smart > >>> server.smartshare.dk/ > >>> > >>> Depends on how we are going to use it. 4 KB suffices if we only want to > >>> use it for "small" structures. > > > > This is what is stated in the doc: > > "Lcore variables are suitable for small objects" > > "The amount of data kept in lcore variables is projected to be small" > > >>> Would 64 KB work as a compromise? > > > > Let's consider based on the need. > > The lcore variables are new and we don't want it to degrade the DPDK > > footprint, > > at least not in this first version. > > 4 KB is a memory page on common systems, > > it looks reasonnable and big enough for a "variable". > > > > Applied, thanks. > > Why do you have maintainers if you just ignore them?
I didn't receive your replies when I started to write this. Please be comprehensive. We are in a hurry to stabilize this before the release candidate which is already late. I'll change to 128 KB as you recommend before pushing to the repository. PS: maybe I should not have merged this feature in 24.11.
