Messages in this thread | | | From | Konrad Rzeszutek Wilk <> | Subject | [PATCH] Bug-fixes to enable PV ticketlock to work under Xen PVHVM with Linux v3.12. (v1) | Date | Sat, 7 Sep 2013 09:46:40 -0400 |
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After a bit of false starts, lots of debugging, and tons of help from Stefano and David on how event mechanism is suppose to work I am happy to present a set of bug-fixes that make PV ticketlocks work under Xen PVHVM with Linux v3.12.
v3.12 has now thanks to commit 816434ec4a674fcdb3c2221a6dffdc8f34020550 (Merge branch 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip) PV ticketlocks. That means: - Xen PV bytelock has been replaced by Xen PV ticketlock. - Xen PVHVM is using ticketlock (not PV variant) - this patch makes it PV. - baremetal is still using ticketlocks.
In other words everything in the kernel is ticketlock based with the virtualizations having the 'PV' part to aid.
Please take a look at the patches. If you are interested in testing them out I will post a git tree on Monday based on v3.11 and v3.12-rc0.
Note that I had not run any performance tests and I am not sure when I will be able to (got other bugs to squash now). I've asked our internal performance engineer to do some benchmarking - but those results won't be available for some time as it takes time to do good benchmarking.
arch/x86/xen/enlighten.c | 1 - arch/x86/xen/smp.c | 17 +++++++++++++++++ arch/x86/xen/spinlock.c | 45 ++++++++------------------------------------- 3 files changed, 25 insertions(+), 38 deletions(-)
(oh neat, more deletions!)
Konrad Rzeszutek Wilk (5): xen/spinlock: Fix locking path engaging too soon under PVHVM. xen/spinlock: We don't need the old structure anymore xen/smp: Update pv_lock_ops functions before alternative code starts under PVHVM xen/spinlock: Don't setup xen spinlock IPI kicker if disabled. Revert "xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM"
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