Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-27 Thread Ilya Maximets
On 9/27/23 17:41, Michael S. Tsirkin wrote: > On Wed, Sep 27, 2023 at 04:06:41PM +0200, Ilya Maximets wrote: >> On 9/25/23 20:04, Ilya Maximets wrote: >>> On 9/25/23 16:32, Stefan Hajnoczi wrote: On Fri, 25 Aug 2023 at 13:02, Ilya Maximets wrote: > > It was supposed to be a compiler

Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-27 Thread Michael S. Tsirkin
On Wed, Sep 27, 2023 at 04:06:41PM +0200, Ilya Maximets wrote: > On 9/25/23 20:04, Ilya Maximets wrote: > > On 9/25/23 16:32, Stefan Hajnoczi wrote: > >> On Fri, 25 Aug 2023 at 13:02, Ilya Maximets wrote: > >>> > >>> It was supposed to be a compiler barrier and it was a compiler barrier > >>>

Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-27 Thread Ilya Maximets
On 9/25/23 20:04, Ilya Maximets wrote: > On 9/25/23 16:32, Stefan Hajnoczi wrote: >> On Fri, 25 Aug 2023 at 13:02, Ilya Maximets wrote: >>> >>> It was supposed to be a compiler barrier and it was a compiler barrier >>> initially called 'wmb' (??) when virtio core support was introduced. >>> Later

Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-25 Thread Ilya Maximets
On 9/25/23 16:32, Stefan Hajnoczi wrote: > On Fri, 25 Aug 2023 at 13:02, Ilya Maximets wrote: >> >> It was supposed to be a compiler barrier and it was a compiler barrier >> initially called 'wmb' (??) when virtio core support was introduced. >> Later all the instances of 'wmb' were switched to

Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-25 Thread Stefan Hajnoczi
On Fri, 25 Aug 2023 at 13:02, Ilya Maximets wrote: > > It was supposed to be a compiler barrier and it was a compiler barrier > initially called 'wmb' (??) when virtio core support was introduced. > Later all the instances of 'wmb' were switched to smp_wmb to fix memory > ordering issues on

Re: [PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-09-25 Thread Ilya Maximets
On 8/25/23 19:01, Ilya Maximets wrote: > It was supposed to be a compiler barrier and it was a compiler barrier > initially called 'wmb' (??) when virtio core support was introduced. > Later all the instances of 'wmb' were switched to smp_wmb to fix memory > ordering issues on non-x86 platforms.

[PATCH] virtio: remove unnecessary thread fence while reading next descriptor

2023-08-25 Thread Ilya Maximets
It was supposed to be a compiler barrier and it was a compiler barrier initially called 'wmb' (??) when virtio core support was introduced. Later all the instances of 'wmb' were switched to smp_wmb to fix memory ordering issues on non-x86 platforms. However, this one doesn't need to be an actual