search for: preempt_enable_no_resch

On Tue, Apr 07, 2020 at 10:03:06PM -0700, Ankur Arora wrote: > +/* > + * preempt_enable_no_resched() so we don't add any preemption points until > + * after the caller has returned. > + */ > +#define preempt_enable_runtime_patch() preempt_enable_no_resched() > +#define preempt_disable_runtime_patch() preempt_disable() NAK, this is probably a stright preemption bug, also, afaic...

...where needed. > > But it would be possible to add a checkpatch test for this. Wasn't the whole purpose of these things for 'drivers' (namely virtio/xen hypervisor interaction) to use these? And I suppose most of virtio would actually be modules, so you cannot do what I did with preempt_enable_no_resched() either. But yes, it would be good to limit the use of these things.

...where needed. > > But it would be possible to add a checkpatch test for this. Wasn't the whole purpose of these things for 'drivers' (namely virtio/xen hypervisor interaction) to use these? And I suppose most of virtio would actually be modules, so you cannot do what I did with preempt_enable_no_resched() either. But yes, it would be good to limit the use of these things.

...ctx->active++; @@ -314,11 +314,8 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) * the user should drop to single cpu before tracing. */ - put_cpu_var(kmmio_ctx); return 1; /* fault handled */ -no_kmmio_ctx: - put_cpu_var(kmmio_ctx); no_kmmio: rcu_read_unlock(); preempt_enable_no_resched(); @@ -333,7 +330,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) { int ret = 0; - struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); + struct kmmio_context *ctx = this_cpu_ptr(&kmmio_ctx);...

On Thu, Dec 31, 2015 at 09:07:59PM +0200, Michael S. Tsirkin wrote: > This defines __smp_xxx barriers for arm, > for use by virtualization. > > smp_xxx barriers are removed as they are > defined correctly by asm-generic/barriers.h > > This reduces the amount of arch-specific boiler-plate code. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> >

On Thu, Dec 31, 2015 at 09:07:59PM +0200, Michael S. Tsirkin wrote: > This defines __smp_xxx barriers for arm, > for use by virtualization. > > smp_xxx barriers are removed as they are > defined correctly by asm-generic/barriers.h > > This reduces the amount of arch-specific boiler-plate code. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> >

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-git13 + patches-2.6.21-git7-070507-1.tar.gz (I think "unwinder" is the only patch which doesn't apply to git13, and the sched-clock patches are the only ones which this series actually needs). Changes since the last posting: - More netfront review and cleanup - Added ability to

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-git13 + patches-2.6.21-git7-070507-1.tar.gz (I think "unwinder" is the only patch which doesn't apply to git13, and the sched-clock patches are the only ones which this series actually needs). Changes since the last posting: - More netfront review and cleanup - Added ability to

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-git13 + patches-2.6.21-git7-070507-1.tar.gz (I think "unwinder" is the only patch which doesn't apply to git13, and the sched-clock patches are the only ones which this series actually needs). Changes since the last posting: - More netfront review and cleanup - Added ability to

Hi, This is the Xen implementation for the paravirt_ops interface. The series is based on 2.6.22-rc1-mm1, and I think its ready to be cooked in -mm with a view to being merged in 2.6.23. The first part of the series is some small changes to the core kernel. Apart from the new code added in "Allocate and free vmalloc areas" (posted many times before), they are simply a few one-liners

Hi, This is the Xen implementation for the paravirt_ops interface. The series is based on 2.6.22-rc1-mm1, and I think its ready to be cooked in -mm with a view to being merged in 2.6.23. The first part of the series is some small changes to the core kernel. Apart from the new code added in "Allocate and free vmalloc areas" (posted many times before), they are simply a few one-liners

Hi, This is the Xen implementation for the paravirt_ops interface. The series is based on 2.6.22-rc1-mm1, and I think its ready to be cooked in -mm with a view to being merged in 2.6.23. The first part of the series is some small changes to the core kernel. Apart from the new code added in "Allocate and free vmalloc areas" (posted many times before), they are simply a few one-liners

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-git3 + ff patches-2.6.21-git3-070501-1.tar.gz. Changes since the last posting: - reviews of xenbus (me), netfront (hch, rusty, herbert xu) and blockfront (hch), with most comments addressed. Netfront review revealed a couple of real bugs, and the code for all three is looking cleaner

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-git3 + ff patches-2.6.21-git3-070501-1.tar.gz. Changes since the last posting: - reviews of xenbus (me), netfront (hch, rusty, herbert xu) and blockfront (hch), with most comments addressed. Netfront review revealed a couple of real bugs, and the code for all three is looking cleaner

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-rc7 + your patches + the last batch of pv_ops patches I posted. This patch generally restricts itself to Xen-specific parts of the tree, though it does make a few small changes elsewhere. These patches include: - some helper routines for allocating address space and walking pagetables - Xen

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21-rc7 + your patches + the last batch of pv_ops patches I posted. This patch generally restricts itself to Xen-specific parts of the tree, though it does make a few small changes elsewhere. These patches include: - some helper routines for allocating address space and walking pagetables - Xen

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21 + 2.6.21-070428-1 + the patches I've posted over the last couple of days. Changes since the last posting: - update per review comments - comment each file - comment barrier use - use common cpu sibling setup - fixed a few minor bugs, specifically a traceirq mismatch warning - some

Hi Andi, This series of patches implements the Xen paravirt-ops interface. It applies to 2.6.21 + 2.6.21-070428-1 + the patches I've posted over the last couple of days. Changes since the last posting: - update per review comments - comment each file - comment barrier use - use common cpu sibling setup - fixed a few minor bugs, specifically a traceirq mismatch warning - some

Unlike full virtualization in which the virtual machine provides the same platform interface as running natively on the hardware, paravirtualization requires modification to the guest operating system to work with the platform interface provided by the hypervisor. Xen was designed with performance in mind. Calls to the hypervisor are minimized, batched if necessary, and non-critical codepaths

Unlike full virtualization in which the virtual machine provides the same platform interface as running natively on the hardware, paravirtualization requires modification to the guest operating system to work with the platform interface provided by the hypervisor. Xen was designed with performance in mind. Calls to the hypervisor are minimized, batched if necessary, and non-critical codepaths