On Thu, Aug 03, 2023 at 06:28:51PM +0800, Guo Ren wrote: > On Thu, Aug 3, 2023 at 4:50 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > > On Wed, Aug 02, 2023 at 07:14:05PM -0400, Guo Ren wrote: > > > > > The pv_ops is belongs to x86 custom frame work, and it prevent other > > > architectures connect to the CNA spinlock. > > > > static_call() exists as a arch neutral variant of this. > Emm... we have used static_call() in the riscv queued_spin_lock_: > https://lore.kernel.org/all/20230802164701.192791-20-guoren@xxxxxxxxxx/ Yeah, I think I saw that land in the INBOX, just haven't had time to look at it. > But we met a compile problem: > > GEN .vmlinux.objs > MODPOST Module.symvers > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [arch/riscv/kvm/kvm.ko] > undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" > [kernel/locking/locktorture.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [mm/z3fold.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" > [fs/nfs_common/grace.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/quota/quota_v1.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/quota/quota_v2.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" > [fs/quota/quota_tree.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/fuse/virtiofs.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/dlm/dlm.ko] undefined! > ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/fscache/fscache.ko] > undefined! > WARNING: modpost: suppressed 839 unresolved symbol warnings because > there were too many) > /home/guoren/source/kernel/linux/scripts/Makefile.modpost:144: recipe > for target 'Module.symvers' failed > > Our solution is: > EXPORT_SYMBOL(__SCK__pv_queued_spin_unlock); > > What do you think about it? Could be you're not using static_call_mod() to go with EXPORT_STATIC_CALL_TRAMP() > > > I'm working on riscv qspinlock on sg2042 64 cores 2/4 NUMA nodes > > > platforms. Here are the patches about riscv CNA qspinlock: > > > https://lore.kernel.org/linux-riscv/20230802164701.192791-19-guoren@xxxxxxxxxx/ > > > > > > What's the next plan for this patch series? I think the two-queue design > > > has satisfied most platforms with two NUMA nodes. > > > > What has been your reason for working on CNA? What lock has been so > > contended you need this? > I wrote the reason here: > https://lore.kernel.org/all/20230802164701.192791-1-guoren@xxxxxxxxxx/ > > The target platform is: https://www.sophon.ai/ > > The two NUMA nodes platform has come out, so we want to measure the > benefit of CNA qspinlock. CNA should only show a benefit when there is strong inter-node contention, and in that case it is typically best to fix the kernel side locking. Hence the question as to what lock prompted you to look at this.
