Re: [PATCH v11 0/3] MR741: ntdll: Implement NtFlushProcessWriteBuffers.

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about dlls/ntdll/unix/virtual.c:
> -
>       a problem since in that case we didn't have permission to lock the memory either */
> -
>    if (ret && errno != EPERM)
> -
>        goto failed;
> -
>    dontneed_page = mem;
> - }
> - /* Force the page into memory to make madvise() have real work to do */
> - *mem = 3;
> - /* Evict the page from memory to force the kernel to send an IPI to all threads of this process,
> -
>   which has the side effect of executing a memory barrier in those threads */
> - success = !madvise( mem, page_size, MADV_DONTNEED );
>
> +#ifdef __aarch64__
> - /* Some ARMv8 processors can broadcast TLB invalidations using the TLBI instruction,
> -
>   the madvise trick does not work on those */
> - if (success && !once++)
> -
>    FIXME( "memory barrier may not work on this platform\n" );
>
> +#endif

I think this should be unconditional and not specific to aarch64. `mprotect()` is and always will be a hack, and other archs might implement TLBI like operation too.