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charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.496, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juan Quintela , Markus Armbruster , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Paolo Bonzini , Den Lunev Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sun, Nov 29, 2020 at 11:12:10PM +0300, Andrey Gruzdev wrote: > > > +void ram_write_tracking_stop(void) > > > +{ > > > +#ifdef CONFIG_LINUX > > > + RAMState *rs = ram_state; > > > + RAMBlock *bs; > > > + assert(rs->uffdio_fd >= 0); > > > > Maybe too harsh - we can return if it's invalid. > > > > Meanwhile, better rcu_read_lock(), as well? > > > > Yep, RCU lock, I'll add. Why too harsh? Just a debug assertion. I was afraid some special path could trigger ram_write_tracking_stop() being called before ram_write_tracking_start(), then vm could crash. If we can guarantee that not happening, then it's also ok with assert(). [...] > > > +/** > > > + * uffd_poll_events: poll UFFD file descriptor for read > > > + * > > > + * Returns true if events are available for read, false otherwise > > > + * > > > + * @uffd: UFFD file descriptor > > > + * @tmo: timeout in milliseconds, 0 for non-blocking operation, > > > + * negative value for infinite wait > > > + */ > > > +bool uffd_poll_events(int uffd, int tmo) > > > > Shall we spell "tmo" out? > In the comment? I think it's ok. I'd suggest to spell it out everywhere, especially in the codes. But feel free to take your own preference. Thanks, -- Peter Xu