Hi, On 2022-11-12 22:28, Guillem Jover wrote: > Hi! > > On Fri, 2022-11-11 at 19:15:59 +0100, Manuel A. Fernandez Montecelo wrote: > > Package: dpkg > > Version: 1.21.9 > > Severity: normal > > X-Debbugs-Cc: m...@debian.org, debian-wb-t...@lists.debian.org > > > After some investigation by aurel32 and myself, this was traced back to the > > commit f8d254943051e085040367d689048c00f31514c3 [2], in which the > > calculation of > > the memory that can be used, to determine the number of threads to use, was > > changed from half of the physical mem to be based on the memory available. > > Ah, thanks for tracking this down! I think the problem is the usual > "available" memory does not really mean what people think it means. :/ > And I unfortunately missed that (even thought I was aware of it) when > reviewing the patch. > > Attached is something I just quickly prepared, which I'll clean up and > merge for the upcoming 1.21.10. Let me know if that solves the issue > for you, otherwise we'd need to look for further changes.
Thanks for providing a patch. I have not been able yet to try it for the case where we have found the issue, i.e. building linux. However I have tried to setup a similar environment: - I took a just booted VM with 4 GB RAM, 4 GB swap and 4 GB tmpfs, and very few things running on it. - I filled the tmpfs with 4 GB of random data, which means that after moving the content of the tmpfs to the swap, 4 GB could still be used without issue. - I ended up with the following /proc/meminfo: MemTotal: 3951508 kB MemFree: 130976 kB MemAvailable: 10584 kB Buffers: 2448 kB Cached: 3694676 kB SwapCached: 12936 kB Active: 3111920 kB Inactive: 610376 kB Active(anon): 3102668 kB Inactive(anon): 606952 kB Active(file): 9252 kB Inactive(file): 3424 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 4194300 kB SwapFree: 3777400 kB Zswap: 0 kB Zswapped: 0 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 12960 kB Mapped: 6700 kB Shmem: 3684416 kB KReclaimable: 27616 kB Slab: 54652 kB SReclaimable: 27616 kB SUnreclaim: 27036 kB KernelStack: 2496 kB PageTables: 1516 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 6170052 kB Committed_AS: 4212940 kB VmallocTotal: 34359738367 kB VmallocUsed: 16116 kB VmallocChunk: 0 kB Percpu: 2288 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ShmemHugePages: 0 kB ShmemPmdMapped: 0 kB FileHugePages: 0 kB FilePmdMapped: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB Hugetlb: 0 kB DirectMap4k: 110452 kB DirectMap2M: 5132288 kB DirectMap1G: 5242880 kB With the current version of dpkg, it means it consider 10584 kB are available (not however that there is 130976 kB of unused physical RAM). With your patch, it's a bit better, as it would be 123408 kB. Still far less that one the VM is capable of. For our use case, I wonder if the memory contained in Shmem (which in that case maps to the memory used for the tmpfs) should be considered as available, as it could be moved to the swap easily. Cheers Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net
