Re: [PATCH v3 3/7] KVM: pfncache: Use RCU for readers instead of a rwlock

On Sun, 2026-08-09 at 18:44 +0100, David Woodhouse wrote:
> On 9 August 2026 16:24:14 BST, Uladzislau Rezki <[email protected]> wrote:
> > On Sun, Aug 09, 2026 at 10:59:59AM +0100, David Woodhouse wrote:
> > > +	/*
> > > +	 * Try a non-blocking allocation first, leaving the spare untouched
> > > +	 * in the common no-pressure case so that it is still there when
> > > +	 * there really is pressure.
> > > +	 */
> > > +	node = kzalloc_objs(*node, rcu_num_nodes, GFP_NOWAIT | __GFP_NOWARN);
> > > 
> > GFP_NOWAIT already contains __GFP_NOWARN. It is odd.
> 
> Ack, thanks. Will fix in my tree.

This is what's actually passing the soak tests and in my tree now.


https://git.infradead.org/?p=users/dwmw2/linux.git;a=shortlog;h=refs/heads/xen-srcu-prealloc

5c37d15f323d (share/xen-srcu-prealloc, xen-srcu-prealloc) srcu: Keep a spare node array so srcu_gp_end() need not block in reclaim
1e0d37cee03e (share/xen-srcu-fixed, xen-srcu-fixed) KVM: x86: Use gfn_to_pfn_cache for steal time / preempted status
5afdd5198536 KVM: x86: Request the guest TLB flush from record_steal_time()
c858c27f88b6 KVM: x86/xen: Don't dirty track "vCPU info" page
8eb4c7e0311b KVM: x86/xen: Explicitly tag "shared info" page as never being dirty tracked
041d33928fbf KVM: x86/xen: Extract delivery of event to vCPU into a separate helper
bcb2923ad118 (share/srcu-conversion, srcu-conversion) KVM: pfncache: Use SRCU for readers instead of a rwlock
36ae6efa3755 mm/mmu_notifier: Remove non_block_start/end() from notifier invocation
7b01d807b50a (share/syzbot, syzbot) KVM: pfncache: use a dedicated invalidation sequence for cache refresh
8604595663ec (share/xen-v2, xen-v2) KVM: x86/xen: Take kvm->srcu in __kvm_xen_has_interrupt()
e9e5a9e1aa46 KVM: x86/xen: Use atomic*() APIs instead of open coded equivalents
380ff63738be KVM: x86/xen: Use 32-bit atomics if vCPU's evtchn_pending_sel isn't aligned
003e94fdb41f KVM: x86/xen: Use 32-bit locked bts for vcpu_info evtchn_pending_sel
d692f06e6c45 KVM: x86/xen: Enforce 4-byte alignment of vcpu_info registration
7a95aafa7ada KVM: x86/xen: Latch shinfo mode in kvm_xen_schedop_poll()
bb8ac0a23f4f KVM: x86/xen: Latch shinfo mode in kvm_xen_set_evtchn_fast()
3300e2ca471e KVM: x86/xen: Rename max_evtchn_port() to kvm_max_evtchn_port()
e8b7e8ae6de8 KVM: x86/xen: Introduce kvm_xen_has_64bit_shinfo() macro
9643c9d83837 KVM: x86/xen: Rename 'longmode' to 'is_64bit' in hypercall handling