From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 65B4F427FA1 for ; Mon, 17 Aug 2026 16:47:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786985252; cv=none; b=tDFTiaY0H/C0N8Dhy60FXYSpH9ITj6svxFMLrwn5CLEk++olsH1C9OjyFLqMBLP6onePPgO8Q/qHNI3m2cBKtcoblPxBHoDPzEoyJBWQM9mJK4x81E1u157gRzM/oQyWFU5bNrwQpTScb8oBPJJFhzJKjHtUaRXpJBEuXCC692Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786985252; c=relaxed/simple; bh=+tW8pjOGAHXB0NgJkafyPn89LfRrA9pJ5guPFB94HUs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M+ANeiQM17G+GndOJy/ikgiEI4KMo5yOF3MmdvD8AQM0vZKVyJZ7gOhgpEP5nKhHo84xFjPCj8H8nWnjT56eNGoHslewL1QCUF2lTHyr+hpYgbbbzDfzEyRQpX95FJeTUTcbmUTXE8Xb5P2Xfhg60hZtqM23UZ5dBtzauqppqMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZdwTlAlP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZdwTlAlP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D4621F000E9; Mon, 17 Aug 2026 16:47:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786985251; bh=kgz+IVMK9TQUnK1lY1PtvWGnfkBc7BrhZWmwgpK+RXc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ZdwTlAlPQspxfYiSSXCPw/KUJfybyvow5Ao7DTHuhA4RVrXwz65khwE/C18iofQ/z SgDtcuzmeuX6db8Zk6VWmYEzT8xAtFqt2R6dAFcY9am/hJfC1Mhf9TxDfj3ZL8VRHm sj3sG+7z39Xmtadox0nUL2zGxgl6/L4u4l0F89imk/wf3W+QScEIW0Ss7eNbg8HIRE foY7YSe8GXoT8xgy/vndNgRaKHel7S9iE1qnyQwC3V0CQRyIYaHkRlc2s+jZFdjZi4 jweq5TIvJDiUXw/wTp29X/ePvhnuumjbYz4HKdSJ1Ron8aHIXyl82pnRXX/rJ3ClYg juZ3ImN8e2rxg== Date: Mon, 17 Aug 2026 17:47:13 +0100 From: "Lorenzo Stoakes (ARM)" To: Zi Yan Cc: Roman Gushchin , Matthew Brost , Andrew Morton , David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: fixing sashiko failure to apply (was Re: [PATCH v5 00/16] mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff) Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Aug 14, 2026 at 10:19:10PM -0400, Zi Yan wrote: > > >> >> > >> >>>> > >> >>>> Sashiko can be guided with a base-commit: tag but I'm not sure how to > >> >>>> tell it what tree/branch to try, or even if that's necessary. Perhaps > >> >>>> someone can figure this out sometime. > >> >>> > >> >>> b4 gives a base commit, but I think because the trees are rebased it ends > >> >>> up being the incorrect one. > >> >>> > >> >>> Not sure what the solution is! > >> >>> > >> >> > >> >> We have seen this on the Xe list (our list is based on drm-tip), > >> >> typically with cross-subsystem patches. Some cross-subsystem patches > >> >> apply and run correctly, while others do not but public CI flows run > >> >> based on drm-tip. I do not have a bisect or a clear understanding of > >> >> what works and what doesn't, but I think it would be very useful if the > >> >> community could better understand the root cause. > >> > > >> > As Mike said, mm-unstable/mm-new is heavily rebased and also carries the old > >> > version of the series before the new one is applied, so it's super unclear what > >> > the base commit should be there. > >> > > >> > But in general, I wonder if it's possible that we could tell sashiko > >> > after-the-fact what base commit to look at once the series is in, or re-trigger > >> > it somehow once it's in-tree? > >> > > >> > Roman - any suggestions on what we could do to help sashiko find things? > >> > > >> > (Once mm-next is in place everything with change again, but can address that > >> > then :) > >> > >> I can implement any reasonable logic here, the problem is that my understanding is > >> the current mm process is a bit vague here. Which likely will be also an issue for the mm ci. > >> I’ll merge a support for b4-like dependencies specification soon. > > > > Yeah I suspect things might be tricky with mm given the rebases honestly. > > > >> > >> Re re-starting with manual selection it’s on my todo list, but maybe a bit lfurther away, as it requires > >> an authorization, etc. > > > > Yeah that's the fly in the ointment I guess for many things like giving instant > > feedback on accuracy, well you want to make sure the person giving it is who you > > think they are :) > > > > Probably an email -> author with magic link or something but thinking through > > how to avoid abuse/spam/rate limiting everything etc. is surely all a pain :) > > If b4 is used, the cover letter comes with a fixed change-id. That can > be a good id for new patch series replacement. For patches do not use > b4, authors can add their own change-id. Without change-id, if the new > version comes with a link to the prior version, that can be helpful too. > If none is present, author email + patch title might be the last resort. > But I think we need to encourage authors to provide some id for their > patches to make replacement easier instead of spending too much effort > on identifying different patch versions. Agree, but with mm constantly rebasing these hashes become potentially less useful :) > > -- > Best Regards, > Yan, Zi > -- Cheers, Lorenzo