similar to: [PULL] virtio: barrier rework+fixes

Hi Linus, Just making sure nothing's wrong with this pull request. If there's an issue, pls let me know! Thanks! On Wed, Jan 13, 2016 at 06:28:55PM +0200, Michael S. Tsirkin wrote: > The following changes since commit afd2ff9b7e1b367172f18ba7f693dfb62bdcb2dc: > > Linux 4.4 (2016-01-10 15:01:32 -0800) > > are available in the git repository at: > >

Changes since v2: - extended checkpatch tests for barriers, and added patches teaching it to warn about incorrect usage of barriers (__smp_xxx barriers are for use by asm-generic code only), should help prevent misuse by arch code to address comments by Russell King - patched more instances of xen to use virt_ barriers as suggested by Stefano Stabellini - implemented a 2 byte xchg on sh

Changes since v2: - extended checkpatch tests for barriers, and added patches teaching it to warn about incorrect usage of barriers (__smp_xxx barriers are for use by asm-generic code only), should help prevent misuse by arch code to address comments by Russell King - patched more instances of xen to use virt_ barriers as suggested by Stefano Stabellini - implemented a 2 byte xchg on sh

Changes since v1: - replaced my asm-generic patch with an equivalent patch already in tip - add wrappers with virt_ prefix for better code annotation, as suggested by David Miller - dropped XXX in patch names as this makes vger choke, Cc all relevant mailing lists on all patches (not personal email, as the list becomes too long then) I parked this in vhost tree for now, but the

Changes since v1: - replaced my asm-generic patch with an equivalent patch already in tip - add wrappers with virt_ prefix for better code annotation, as suggested by David Miller - dropped XXX in patch names as this makes vger choke, Cc all relevant mailing lists on all patches (not personal email, as the list becomes too long then) I parked this in vhost tree for now, but the

On Sun, Jan 03, 2016 at 11:12:44AM +0200, Michael S. Tsirkin wrote: > On Sat, Jan 02, 2016 at 11:24:38AM +0000, Russell King - ARM Linux wrote: > > My only concern is that it gives people an additional handle onto a > > "new" set of barriers - just because they're prefixed with __* > > unfortunately doesn't stop anyone from using it (been there with >

On Sun, Jan 03, 2016 at 11:12:44AM +0200, Michael S. Tsirkin wrote: > On Sat, Jan 02, 2016 at 11:24:38AM +0000, Russell King - ARM Linux wrote: > > My only concern is that it gives people an additional handle onto a > > "new" set of barriers - just because they're prefixed with __* > > unfortunately doesn't stop anyone from using it (been there with >

On Sun, Jan 10, 2016 at 04:16:32PM +0200, Michael S. Tsirkin wrote: > From: Davidlohr Bueso <dave at stgolabs.net> > > With commit b92b8b35a2e ("locking/arch: Rename set_mb() to smp_store_mb()") > it was made clear that the context of this call (and thus set_mb) > is strictly for CPU ordering, as opposed to IO. As such all archs > should use the smp variant of

On Sun, Jan 10, 2016 at 04:16:32PM +0200, Michael S. Tsirkin wrote: > From: Davidlohr Bueso <dave at stgolabs.net> > > With commit b92b8b35a2e ("locking/arch: Rename set_mb() to smp_store_mb()") > it was made clear that the context of this call (and thus set_mb) > is strictly for CPU ordering, as opposed to IO. As such all archs > should use the smp variant of

mb() typically uses mfence on modern x86, but a micro-benchmark shows that it's 2 to 3 times slower than lock; addl that we use on older CPUs. So we really should use the locked variant everywhere, except that intel manual says that clflush is only ordered by mfence, so we can't. Note: some callers of clflush seems to assume sfence will order it, so there could be existing bugs around

mb() typically uses mfence on modern x86, but a micro-benchmark shows that it's 2 to 3 times slower than lock; addl that we use on older CPUs. So we really should use the locked variant everywhere, except that intel manual says that clflush is only ordered by mfence, so we can't. Note: some callers of clflush seems to assume sfence will order it, so there could be existing bugs around

This is really trying to cleanup some virt code, as suggested by Peter, who said > You could of course go fix that instead of mutilating things into > sort-of functional state. This work is needed for virtio, so it's probably easiest to merge it through my tree - is this fine by everyone? Arnd, if you agree, could you ack this please? Note to arch maintainers: please don't

This is really trying to cleanup some virt code, as suggested by Peter, who said > You could of course go fix that instead of mutilating things into > sort-of functional state. This work is needed for virtio, so it's probably easiest to merge it through my tree - is this fine by everyone? Arnd, if you agree, could you ack this please? Note to arch maintainers: please don't

On Fri, 30 Nov 2018, Kees Cook wrote: >On Fri, Nov 30, 2018 at 11:27 AM Jarkko Sakkinen ><jarkko.sakkinen at linux.intel.com> wrote: >> >> In order to comply with the CoC, replace **** with a hug. I hope this is some kind of joke. How would anyone get offended by reading technical comments? This is all beyond me... Thanks, Davidlohr

Hi Michael, On Thu, Dec 31, 2015 at 09:08:22PM +0200, Michael S. Tsirkin wrote: > This defines __smp_xxx barriers for metag, > for use by virtualization. > > smp_xxx barriers are removed as they are > defined correctly by asm-generic/barriers.h > > Note: as __smp_XX macros should not depend on CONFIG_SMP, they can not > use the existing fence() macro since that is

Hi Michael, On Thu, Dec 31, 2015 at 09:08:22PM +0200, Michael S. Tsirkin wrote: > This defines __smp_xxx barriers for metag, > for use by virtualization. > > smp_xxx barriers are removed as they are > defined correctly by asm-generic/barriers.h > > Note: as __smp_XX macros should not depend on CONFIG_SMP, they can not > use the existing fence() macro since that is

On Mon, 4 Jan 2016 22:18:58 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Mon, Jan 04, 2016 at 02:45:25PM +0100, Peter Zijlstra wrote: > > On Thu, Dec 31, 2015 at 09:08:38PM +0200, Michael S. Tsirkin wrote: > > > This defines __smp_xxx barriers for s390, > > > for use by virtualization. > > > > > > Some smp_xxx barriers

On Mon, 4 Jan 2016 22:18:58 +0200 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Mon, Jan 04, 2016 at 02:45:25PM +0100, Peter Zijlstra wrote: > > On Thu, Dec 31, 2015 at 09:08:38PM +0200, Michael S. Tsirkin wrote: > > > This defines __smp_xxx barriers for s390, > > > for use by virtualization. > > > > > > Some smp_xxx barriers

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> >