From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 193FED13588 for ; Mon, 28 Oct 2024 08:41:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 93E8C6B0085; Mon, 28 Oct 2024 04:41:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EF256B0088; Mon, 28 Oct 2024 04:41:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B64E6B008A; Mon, 28 Oct 2024 04:41:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 5A5E66B0085 for ; Mon, 28 Oct 2024 04:41:54 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 4338C1411ED for ; Mon, 28 Oct 2024 08:41:30 +0000 (UTC) X-FDA: 82722366552.17.06155ED Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf05.hostedemail.com (Postfix) with ESMTP id 71E5C100002 for ; Mon, 28 Oct 2024 08:41:08 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=x3TXW5jz; dkim=pass header.d=linutronix.de header.s=2020e header.b=VQAr2k4I; spf=pass (imf05.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1730104833; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1H44vgesP1XQXrv9CcIfmLIuQ+1Lb7UWNVl5j+TBJ08=; b=HBZ8KA0nNInLo0WJ27oloUjDR917b6i+mtXgCdFeEvyo6b2HqaayWaOol23opSCv1P857V 1kP9NHFZ6pwtmiEkBe7PcJpl+1JuzGFc5J6K/wL4X73Mu/SCp6K31NYRKmROyhOjkMSEM+ z1KIG9Y6YvDIAkdig+EGXjT+XEBNAWE= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=x3TXW5jz; dkim=pass header.d=linutronix.de header.s=2020e header.b=VQAr2k4I; spf=pass (imf05.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1730104833; a=rsa-sha256; cv=none; b=6bodyJJFL/KmgOG2I4gwL5YQRqNx1eCA8FX2MM6xwsKR6YzHA+Q15XQ0C4wM56EBtDsdWc cvJxwy9C4w+0bnu/PhgXdkS5FT/Yug+Be6wgBTFxA1MfQw1AhuG5iMuWENc+jGnAgefbVj Tfq9hQclgm6vf0vkGSEGsxbfUQiYLFA= From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1730104909; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1H44vgesP1XQXrv9CcIfmLIuQ+1Lb7UWNVl5j+TBJ08=; b=x3TXW5jzTZtadCH2BFHWSDUQsinXPlK0IrDDFRy/3tNQK0hzy3RehZqmDb5+LDPS5kOzQc sjnMxY5k25sQYGXLGYjtF6Teg3B84jy/bMViihmY1+l351ebf71jlbT5IqfVe40dQneeB3 vKETQHeiYHoTnMEQ4/E9gkHBCmVSG0H21a4FRwH9RLTNgC4pNPkvjcWbza9iOzYXpTcOb6 NKB13JlaGMBXliD2Dq9Na5nEvaPDkQYWh7KYhQShbbhXtic1cULYTlUI4tJPwgU550RGvk lUPOTglWIlyyGcXjEuR58wOsJ4hJd0Zpv72EbpMDTC6edTBiAM+tatV4FIUG1A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1730104910; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1H44vgesP1XQXrv9CcIfmLIuQ+1Lb7UWNVl5j+TBJ08=; b=VQAr2k4I06KdONU7UIdNQErDeF0PPVIHebz4hNbPiOnA40OILCuO/XnqUe/puyjjeB+a6q D8khm6vUYCuFTgCQ== To: Hugh Dickins , Alexander Viro Cc: Andrew Morton , Christian Brauner , Matthew Wilcox , Christoph Hellwig , Kent Overstreet , "Darrick J. Wong" , Peter Zijlstra , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds Subject: Re: [PATCH] iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP In-Reply-To: References: Date: Mon, 28 Oct 2024 09:41:48 +0100 Message-ID: <874j4w4o1f.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 71E5C100002 X-Stat-Signature: cd1q6urhfc36oezwrcnrpwgnqfmf5rbe X-HE-Tag: 1730104868-864210 X-HE-Meta: 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 zKU7QPUn YTjm3u8OhGHbRUGIhEzetp13bNNvLII3Lhezf5YhgGcGq9tH2i/h7Ggrk1w0QDI64kHhyGnwuQq1CdorbEKWmJNuDUvd8QZviSom7gi6aRVneKXjOYnKQsYYoMjdjgaSiFViLUkwi9r9yti5e55+ID9pbJst4DlXPu54Rxhf+Avo9OJWlolIr4euX3o6KMRQ/xx+eRIEVpnl+Ufk= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Oct 27 2024 at 15:23, Hugh Dickins wrote: > generic/077 on x86_32 CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y with highmem, > on huge=always tmpfs, issues a warning and then hangs (interruptibly): > > WARNING: CPU: 5 PID: 3517 at mm/highmem.c:622 kunmap_local_indexed+0x62/0xc9 > CPU: 5 UID: 0 PID: 3517 Comm: cp Not tainted 6.12.0-rc4 #2 > ... > copy_page_from_iter_atomic+0xa6/0x5ec > generic_perform_write+0xf6/0x1b4 > shmem_file_write_iter+0x54/0x67 > > Fix copy_page_from_iter_atomic() by limiting it in that case > (include/linux/skbuff.h skb_frag_must_loop() does similar). > > But going forward, perhaps CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is too > surprising, has outlived its usefulness, and should just be removed? It has caught real problems and as long as we have highmem support, it should stay IMO to provide test coverage. Thanks, tglx