From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B8BAC84A2B for ; Sat, 8 Feb 2025 01:38:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738978695; cv=none; b=Fq2w8bs/T9rvhPDT4qdKmOJ/8EEpVp9DgcR5VPMiMG5nxHKv4tTndga7GON3eAhHsSxw9tOd4MoxdLfXJ4RvXbC2kPGkXERqnT5f2fcDD6O8dxFsAdES784EZLF1gBl7WgKE1jWvr2z6smucD7tousqzCjy34fYWSQUPnuFB/SI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738978695; c=relaxed/simple; bh=9l26VWfyG6FsKW9zKg4RNpZKAegl42nCqtAfIqEGxIY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Yae3iny+jhmHlin7pyrdXj3ZO4+IXHVeSo6MPff/o+wDQxc+6uqH27wnpPowIYYJV/Qp/dLOp4GSD2C8ZuYu63VmiRVxaa5BXczvDrJbuLPVJ+LpfBIUO9CRMaM9IgTsuGU8fiF1rum31gW36QWAyTPyiHDmAXPCnw4Aa9xO/XA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZlzZCPDR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZlzZCPDR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A78F7C4CED1; Sat, 8 Feb 2025 01:38:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738978695; bh=9l26VWfyG6FsKW9zKg4RNpZKAegl42nCqtAfIqEGxIY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZlzZCPDR6frw7KJxzRCPiADB+gLu2f8e3ztrgjFvQnYIndS/LlGF9AI78X3QfSREH Ry23qgzZBd6wAsEP7fl7sV4Nf5j/gTjCCF5FXPV5bdeRLqmr89VoChyeNMX6Xi6593 DaW3Idb1pAe3HpMWxyLyRq7eeHuOavfMIwxerVCFWg9gXN4BI25nChPJRZSAcLK4Cr Idx+OoaKGmjRS3kQsPxz2gfKwBTDP58QOPwHILs9JPFn16CVZpDCzMj23QPas/ftB0 9ojBD+jl9ZpGnVls51lRexFxpC/IcAkY7uCFmZTSeKLoGg2eX/TQOOKs30yu/MK7Gz fXN68Kr5C4N7w== Date: Fri, 7 Feb 2025 17:38:13 -0800 From: Jakub Kicinski To: Linus Torvalds Cc: Andrew Morton , Bart Van Assche , linux-mm@kvack.org, Ivan Shapovalov , Vlastimil Babka , David Laight , Nathan Chancellor , Pasha Tatashin , David Rientjes , David Hildenbrand , Kaiyang Zhao , Joel Granados , Sourav Panda , Johannes Weiner , llvm@lists.linux.dev, Nathan Chancellor Subject: Re: [PATCH] mm: Fix clang W=1 compiler warnings Message-ID: <20250207173813.5081ba76@kernel.org> In-Reply-To: References: <20250131191231.1370466-1-bvanassche@acm.org> <20250207164926.6daeac77@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 7 Feb 2025 17:01:00 -0800 Linus Torvalds wrote: > On Fri, 7 Feb 2025 at 16:49, Jakub Kicinski wrote: > > Could we possibly please still consider taking this in for 6.14? :( > > Since the warning comes from vmstat.h pretty much every object file > > generates this warning. clang 19 is getting more widely used now, > > its making it hard to see new warnings. > > So: > > - I build the kernel with clang, but I don't have clang-19, so it's > kind of pointless sending patches that DO NOT EVEN EXPLAIN WHAT THE > WARNINGS ARE. > > - and even if you explain *WHAT* the warnings are, please also > explain *WHY* they are valid and should be cared about. > > Because honestly, W=1 is literally meant for "warnings that aren't > necessarily valid". That's why they aren't on by default. > > So no, I'm certainly not applying unexplained random patches that > don't bother to explain the what or the why. Not for 6.14, not ever. I thought I'd ask.. :) FWIW this for every single object: CC net/core/request_sock.o In file included from ../net/core/request_sock.c:14: In file included from ../include/linux/tcp.h:17: In file included from ../include/linux/skbuff.h:17: In file included from ../include/linux/bvec.h:10: In file included from ../include/linux/highmem.h:8: In file included from ../include/linux/cacheflush.h:5: In file included from ../arch/x86/include/asm/cacheflush.h:5: In file included from ../include/linux/mm.h:2224: ../include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 505 | item]; | ~~~~ ../include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 512 | NR_VM_NUMA_EVENT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~~ ../include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 525 | NR_VM_NUMA_EVENT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~~ 3 warnings generated. > Fix the patch. Explain the problem. And possibly just disable the warning. That'd be great. Nathan, would that be okay with you?