On 12.12.2023 10:47, Juergen Gross wrote: > Allow 16 bits per cpu number, which is the limit imposed by > spinlock_tickets_t. > > This will allow up to 65535 cpus, while increasing only the size of > recursive spinlocks in debug builds from 8 to 12 bytes.
I think we want to be more conservative here, for the case of there being bugs: The CPU holding a lock may wrongly try to acquire it a 2nd time. That's the 65536th ticket then, wrapping the value. Therefore my suggestion would be to only (mention) go(ing) up to 32k. > Signed-off-by: Juergen Gross <jgr...@suse.com> > --- > xen/common/spinlock.c | 1 + > xen/include/xen/spinlock.h | 18 +++++++++--------- > 2 files changed, 10 insertions(+), 9 deletions(-) Shouldn't this also bump the upper bound of the NR_CPUS range then in xen/arch/Kconfig? Jan
