*** This bug is a duplicate of bug 1812728 *** https://bugs.launchpad.net/bugs/1812728
** This bug has been marked a duplicate of bug 1812728 linux-gcp: Reduce boot latency due to RAID6_PQ -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1811277 Title: GCE: RAID6_PQ module adds boot latency - can RAID6_PQ be provided as a module Status in linux package in Ubuntu: Triaged Bug description: Google reports: For a n1-standard-2 with ubuntu-1604, we spend around 600 milliseconds during boot on computing the best raid6 recovery algorithm seen in the following lines of the kernel logs: ... [ 2.216022] raid6: sse2x1 gen() 8570 MB/s [ 2.264029] raid6: sse2x1 xor() 6467 MB/s [ 2.312030] raid6: sse2x2 gen() 10602 MB/s [ 2.360021] raid6: sse2x2 xor() 6999 MB/s [ 2.412028] raid6: sse2x4 gen() 12483 MB/s [ 2.464022] raid6: sse2x4 xor() 8607 MB/s [ 2.516024] raid6: avx2x1 gen() 16712 MB/s [ 2.568020] raid6: avx2x1 xor() 12050 MB/s [ 2.620019] raid6: avx2x2 gen() 19393 MB/s [ 2.672024] raid6: avx2x2 xor() 12406 MB/s [ 2.724034] raid6: avx2x4 gen() 22330 MB/s [ 2.776029] raid6: avx2x4 xor() 15196 MB/s [ 2.780440] raid6: using algorithm avx2x4 gen() 22330 MB/s [ 2.786035] raid6: .... xor() 15196 MB/s, rmw enabled [ 2.791196] raid6: using avx2x2 recovery algorithm ... This raid6 computation is a result of including the raid6_pq module statically. Based on the output of `lsmod`, is there any reason this couldn't just be used as a module? ryanrose@ryanrose-boottimes-ubuntu16-test:~$ lsmod Module Size Used by ... btrfs 1101824 0 raid10 49152 0 raid456 143360 0 async_raid6_recov 20480 1 raid456 async_memcpy 16384 2 raid456,async_raid6_recov async_pq 16384 2 raid456,async_raid6_recov async_xor 16384 3 async_pq,raid456,async_raid6_recov async_tx 16384 5 async_xor,async_pq,raid456,async_memcpy,async_raid6_recov xor 24576 2 async_xor,btrfs raid6_pq 118784 4 async_pq,btrfs,raid456,async_raid6_recov raid1 40960 0 raid0 20480 0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1811277/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp