From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.224 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794309954; b=zIzFVinyMVGJ0Q1ZZcfOd7/9Gzy2Ba133yzGTvm1dSJ4d5oVeGNrN+8aoHzs3zpjoW3n 51vzT5rsV4uLiOLk4S98FCRrmld53J6xNbrCTZ0TVWapVeZ6gws+N60QDIooxmfNY3w6g Rq4xDBgm/GtDETuKkIou5fbj0/1CP/yyK2UPxpzWnzbcCMxXo22fvtYKV11vkClhO8Xui nJ03eDKuS43Nc+92/8hTIXS5IZWCpDOrLYS1ViEsf1b1Zc/H0eoH1XX3BzIzqSNrE6Io2 yq3NC5XoYAp5og65GhCo4Fu4bhXWvq8fEo/vPPN5NtwsM9zI729jZ6aByptfeBKMDeg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794309954; 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=Sue5VZ/aX4AnT6uuVBegYA7wi8IsAo/rywAYslrKIpvuu1dxakD+a3Wqu1dK9Hgvy5Bb 7174+nVUNV8x+vnQq0n0mBcAFH5a2or9MkVcJzmyv6ReJ7wo0a61vfEHlgt4Q43HXjWAx ohPr0XUIVZ2rEPWveupyCW9SMTJ5nQQDc1VodpW0n+K6LzI2R3k5ZvERZRHZivnIKlKRN o3tTknjmlXvB2r7ZeaRTsTK1jQvLQfm93epFdMXXoOhzAhG5b73g8E5qeTKCzdqL36Bj2 bemPC6S1VzxEWNpS1FvX0G9JnmKY4cgtFJUU2CilO1UcN8NJoANEk+tOWM0oRMSQDIQ== 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=NgWqlnkR; arc=none smtp.remote-ip=91.218.175.224 Received: from mta0.migadu.com (out-224.mta0.migadu.com [91.218.175.224]) (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 9100E606A337 for ; Tue, 10 Nov 2026 11:25:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 9100E606A337 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=NgWqlnkR 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=1794309951; v=1; x=1794914751; b=NgWqlnkRqjCIk49MKFVio9mm9PWHktC4BBp1DK7KyfVUifUVLIxERfcDf17sWV83KCpahdcp 4c6ilH8eenxZmHvJUJWbSzIiYvPLoT+q5CS3W9XMeTDe0nJRkxt95P/RRs+f71jAjRLScYeNQ2M g70EFpXAULqpyxoh8lMGa7dk= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 0846a03f7f9c0cfe; Tue, 10 Nov 2026 11:25:41 +0000 X-Mizu-Trace-ID: 0846a03f7f9c0cfe X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Uladzislau Rezki , Dev Jain , Suren Baghdasaryan , Andrew Morton , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Dennis Zhou , Tejun Heo , Christoph Lameter Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Hao Ge Subject: [PATCH v4 9/9] mm/percpu: stop unmapping the CPU that failed to map Date: Tue, 10 Nov 2026 19:25:46 +0800 Message-Id: <20261110112546.261415-10-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20261110112546.261415-1-hao.ge@linux.dev> References: <20261110112546.261415-1-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