Quoting Lionel Landwerlin (2019-08-09 13:38:57) > On 09/08/2019 14:58, Chris Wilson wrote: > > Not atomic (the u64 write should really be to avoid total corruption) > > and nothing prevents userspace from racing. How safe is that in the > > overall design? > > > Atomic would prevent issue related to 2 processes/threads seeing > different values because of caching? No, the kernel atomics themselves do not guarantee memory barriers in all cases. The issue I see here is that we can not safely do a u64 increment on all platforms without write tearing. E.g. two clients simultaneously incrementing from U32_MAX becomes 0x1 (both would report U32_MAX) -Chris _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
