From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.96 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793001808; b=C6u+vLG9F5zNfO2hn+HawyAypmu6+rQfUxdvYpuy3241C+47yiWGr0pDggW20ti6totA mpayFluczPA1TyHTF7WLga9mT9uQ+COYfVIz2J+ghin33DKx/Fvy3bxJALH2yXc2qgTq1 HvQlfjh/SgiZqXrpgrDFO0nktAp2zOB33DQaCAArRBL+161Iw14OYdpz9iYT+SKJBozzd 3ProyvEjWrRUpZ89djbV9SMEYIKCKSVbiFIfqoIKtY4zTuYnmqz2ly2qiQx7GJu5LcB+9 8uJuRNiV1+F9Oc/dqnsv7oE6NWeNZye66Nsh7LiVtQ8apn7BmLAQL+1OJmX09gB4lNw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793001808; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-Id: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=xXtS8nqPI8bMiiZsI5aMJRhf4Xi82nV2lL/o/RcncNM=; b=IAJQoenugAzK2nsFSMqKsH5O6jsCIyuKjf457PewRiYu7VvGBVdMLQqj1QF3LP78iZSB Q6xGtKOWSAsZfTmwgUNj5qpT9U0kVGJv4dfdkI1MdgPLkz5QCcKICl+d5u2qNKWrgIjn/ h126bVouMlt/EAfyH7IBbMDBi085FxvOS93OcktDH6W8WPSImVPLyZSOOWn2fYL5diMMi a1fB7G2lc4PvKdG/j+40YQamZf6n34+7LcmC0XmVSwqbZr9LGW9KWsma2rzInIurZrT+Y /UkBWFgpEupI9jB70paClTyOyzVK/auVd5yNi4GLdmT9/+1glQ0/CScF1rm4sy058pA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=b4JDoQom; arc=none smtp.remote-ip=95.215.58.96 Received: from mta1.migadu.com (out-96.mta1.migadu.com [95.215.58.96]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 359C2606A322 for ; Mon, 26 Oct 2026 08:03:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 359C2606A322 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=b4JDoQom X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=5qs+zHZlkyqRDMqx7SNWEDLyLXIGQ6DciwEgGF1OF3Y=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793001806; v=1; x=1793606606; b=b4JDoQom0Koi8+FkzooWTOyPmsr0fbisC++3eRpFProHJO7+Si+JBtJij98PWU28h+c4QRA9 AV9k3+2v7Ud3w7hGWKerJwW0MY5hJvXXKVcgj36+5a/KSDfDvD1d6KPl+vsmMDccHSTWq+SYXK+ kfJ+Jd0or1Hgp+JFMEZU8qyU= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 63343c3c8e1494da; Mon, 26 Oct 2026 08:03:25 +0000 X-Mizu-Trace-ID: 63343c3c8e1494da X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , Uladzislau Rezki , Hao Ge , Suren Baghdasaryan , Dev Jain Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: [PATCH v3 10/10] mm/percpu: stop unmapping the CPU that failed to map Date: Mon, 26 Oct 2026 16:03:29 +0800 Message-Id: <20261026080329.140244-11-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20261026080329.140244-1-hao.ge@linux.dev> References: <20261026080329.140244-1-hao.ge@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit __pcpu_map_pages() clears the PTEs it installed when it fails, so pcpu_map_pages() only has to tear down the CPUs it mapped before the failing one. Reviewed-by: Suren Baghdasaryan Reviewed-by: Uladzislau Rezki (Sony) Signed-off-by: Hao Ge --- mm/percpu-vm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index 509d8901835c..59d3a336a6bd 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c @@ -252,10 +252,11 @@ static int pcpu_map_pages(struct pcpu_chunk *chunk, struct page **pages, return 0; err: for_each_possible_cpu(tcpu) { - __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), - page_end - page_start); + /* The failing CPU's partial mapping undoes itself */ if (tcpu == cpu) break; + __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), + page_end - page_start); } pcpu_post_unmap_tlb_flush(chunk, page_start, page_end); return err; -- 2.25.1