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 E749240B364; Fri, 31 Jul 2026 12:54:37 +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=1785502479; cv=none; b=BvtznzRP7Pwra8pPn43XoTFrXtqt09y0pdMrMnkUAbUiPbSaW1Muqguh8wYhnhb44Mz+yDHZ+xg23GVLKEIvEFDeU/IbwL/wMJ3+e0cHmcpmDZNilyW2bxIxGb+h3JZAy3trLqGBry+K1/d5bmcBSQYs7Uc3NIZeIDbM/R9cJiA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785502479; c=relaxed/simple; bh=arJLDTm4SQgaOqkJMu265y19GUPya0NqRXB0uL5aZNg=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=kBPIrcu+2m8BfkEHKIPX0XMzNP6VX8tC4V0YO7ZDXY4YY2tLFaF3xABAJtt7lX3ny64NcYz5jpG+wpfJKgjumm/lUMG0SQ02zQjagM2FiggPb9zaob6yBeamASmPOf+FkERKUqQ1YwajAUXc+hJ79AhTp9wIxzsbA+uUHvcPei0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zt+6u3js; 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="Zt+6u3js" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75F931F000E9; Fri, 31 Jul 2026 12:54:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785502477; bh=VOjbtnHvFY4qYQxlLF/zgjoDjZU515ttThtSCI5MrWU=; h=Date:Subject:From:To:Cc:References:In-Reply-To; b=Zt+6u3jsucCzHp0X+ckZPchw3uuTBkAzPN+fcECNBUy+TSw0mvBQEiq+AsQYlCZ1n GZh76NCkY1azHIPhUmnXjKW6gNQXRMqinP1c3dXOX60IQgkdvD54eVdq088W0iJj0X Qz+7qi2iK4GQrzYWcyZjinnGR2e1Ec5Tnw3pFyAfgIGYV7ve8XERBmCSEwuNTnIJMs mjLip89r1JKDdJAbHI1ibLnjfdo7EXm7A0dufozwH6A8EiFj8aATNgjSQq5rkXS/66 RMPHG4v+6bwESGkxfiuXH3OKAxs/JFHEET40/ey2xpuThqL1nnVTdBNP32dQUN1+95 Ui75Dnwgv2uow== Message-ID: <60021f1b-0533-430d-8ed3-6fa331b4e7e6@kernel.org> Date: Fri, 31 Jul 2026 14:54:33 +0200 Precedence: bulk X-Mailing-List: linux-next@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: linux-next: manual merge of the slab tree with the rcu tree Content-Language: en-US From: "Vlastimil Babka (SUSE)" To: Miguel Ojeda , broonie@kernel.org Cc: harry@kernel.org, linux-kernel@vger.kernel.org, linux-next@vger.kernel.org, paulmck@kernel.org, puranjay@kernel.org, Alice Ryhl , Boqun Feng , Greg Kroah-Hartman References: <20260731075644.20215-1-ojeda@kernel.org> <7abffd3a-cc96-46e9-a85b-7dbc9cadc21e@kernel.org> Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <7abffd3a-cc96-46e9-a85b-7dbc9cadc21e@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/31/26 11:59, Vlastimil Babka (SUSE) wrote: > On 7/31/26 09:56, Miguel Ojeda wrote: >> On Thu, 30 Jul 2026 15:38:48 +0100 Mark Brown wrote: >>> >>> Today's linux-next merge of the slab tree got a conflict in: >>> >>> mm/slab_common.c >>> >>> between commit: >>> >>> 736084507faa3 ("rcu: Rename struct rcu_gp_oldstate to rcu_gp_seq") >>> >>> from the rcu tree and commit: >>> >>> bdd0cc9f0ffc3 ("mm/slab: introduce struct kvfree_rcu_head for kvfree_rcu batching") >>> >>> from the slab tree. >> >> The slab one semantically conflicts as well with commit: >> >> e5e86df8b666 ("rust: poll: use kfree_rcu() for PollCondVar") >> >> from the char-misc tree: >> >> error[E0308]: mismatched types >> --> rust/kernel/sync/poll.rs:175:44 >> | >> 175 | unsafe { bindings::kvfree_call_rcu((*ptr).rcu.get(), ptr.cast::()) }; >> | ------------------------- ^^^^^^^^^^^^^^^^ expected `*mut kvfree_rcu_head`, found `*mut callback_head` >> | | >> | arguments to this function are incorrect >> | >> = note: expected raw pointer `*mut bindings::kvfree_rcu_head` >> found raw pointer `*mut bindings::callback_head` >> note: function defined here >> --> rust/bindings/bindings_generated.rs:90407:12 >> | >> 90407 | pub fn kvfree_call_rcu(head: *mut kvfree_rcu_head, ptr: *mut ffi::c_void); >> | ^^^^^^^^^^^^^^^ >> >> The C API was not meant to have a visible effect, but we don't use the >> `kvfree_rcu()` macro, so we notice the change. We can add a similar cast >> to the C side: >> >> diff --git a/rust/kernel/sync/poll.rs b/rust/kernel/sync/poll.rs >> index 684dfa242b1a..79d7e08215b0 100644 >> --- a/rust/kernel/sync/poll.rs >> +++ b/rust/kernel/sync/poll.rs >> @@ -172,6 +172,6 @@ fn drop(&mut self) { >> unsafe { bindings::__wake_up_pollfree((*ptr).inner.inner.wait_queue_head.get()) }; >> >> // SAFETY: This was allocated using `KBox::pin_init`, so it can be freed with `kvfree`. >> - unsafe { bindings::kvfree_call_rcu((*ptr).rcu.get(), ptr.cast::()) }; >> + unsafe { bindings::kvfree_call_rcu((*ptr).rcu.get().cast(), ptr.cast::()) }; >> } >> } >> >> Clippy doesn't complain about the "unneeded" `cast()` under >> `CONFIG_KVFREE_RCU_BATCHED=n`, so it should be fine. > > Thanks! Should I thus amend bdd0cc9f0ffc3 ("mm/slab: introduce struct > kvfree_rcu_head for kvfree_rcu batching") with this fixup or you'll do that > in the char-misc tree? I see, it has to be in char-misc which introduces that patched code, we don't have it. >> Cc: Alice Ryhl >> Cc: Boqun Feng >> Cc: Greg Kroah-Hartman >> Cc: Harry Yoo (Oracle) >> Cc: Vlastimil Babka (SUSE) >> >> Cheers, >> Miguel >