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Berrange" , Richard Henderson Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::232; envelope-from=stefanha@gmail.com; helo=mail-oi1-x232.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 13 Sept 2023 at 04:13, Michael Tokarev wrote: > > [Added some more active patch reviewers to Cc] > > Hi! > > Yesterday I wrote email about picking up changes from master > for previous stable release(s). What's interesting is that > yesterday, basically in a single day, we've faced numerous > examples of subsystem changes which makes such backporting > significantly more difficult than might be. > > For example, recent tpm bugfix, which is trivial by its own, > uses RETRY_ON_EINTR helper which were introduced recently and > which is now used everywhere. coroutine_fn et al markers is > another example, translator_io_start is yet another, and so > on and so on. > > When adding such subsystems/helpers which are to be used widely, > please split the initial implementation patch out of a single > "introduce foo; convert everything to use it" change. Instead, > add the feature in a small patch first, and convert all users > tree-wide to it in a second, subsequent patch, maybe removing > the old version in that second patch too. Where it makes sense > ofcourse, - sometimes it is not possible or just complicated to > do that, like when old and new implementations can't be supported > in parallel. > > Just by splitting "introduce" from "convert", especially for > something simple which will be used all around, you'll greatly > simplify stable trees maintenance. The general concept makes sense to me but I'm not sure what the specific issue with adding (?) coroutine_fn was. Can you link to the patch that caused difficulties so I can review it? Thanks, Stefan