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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D4DF3CCF2DB for ; Mon, 19 Oct 2026 05:45:17 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4j7Pdg5MW7z2yfD; Mon, 19 Oct 2026 16:45:11 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2001:41d0:203:375::4d" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1792388711; cv=none; b=Zh1PmhVfvFQBJzT/xt7gMzNa7xpvmTl9Uy3rrOaepVHtLPgHwEUprzvzhTCWIVNbVek2ps2xFFW1zazw2bhQ3TfEw5wTuoxvkJqeYCRmHcOlwW1YUACRFFzOoEF8BDt06OZzj8KzgJYQPZyKymgj8cPh6pxhdrMlKArV6TApj30zIWs3EPW3A8usYV+ulKCIkkt04NOwAY+Po+wn41rNGhfFDqaWJSN5eX8lxFHuPPgJaXa7eFAcA5t9tEBhrvSwYeJKpmpRz37b2qQKzXN2U+/eVmt8xMm3/XdcIG774XcW3ofccIuShmR2FRZdW1w0lmSbrlEr//5t74cYIFUAVA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1792388711; c=relaxed/relaxed; bh=xXtS8nqPI8bMiiZsI5aMJRhf4Xi82nV2lL/o/RcncNM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Asi765L8uny1Hmdl7GNzNAyeVLmxyH7zcxbNbCasG7OimLiB7bJgOinfxry5tpJ0TLNIbC2RNYfsbUx4ry/KW8R3P0TADVWkTAaAHrvv02Ysw0/SFfImg6hmo3JjnHQyKndxNV6R93yfUX7PMYkyLWVLozF4DCTAkYc0mmYAxXSmZg/74csaHqLpQ/jx5SrWNcydHLZqjgpcvM01HsLnnY+kd4NXS11hDeECoE9KfZ+WjCLdRUt6w+huMcwo0O1m27skgxX3ZWxQ3MRP2a8HOnYDG+ymZLElS68nknHTtATAp9wO3dZOr8h7sLPhN13+vcv76Pb5DJOFF8VX0N7coQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MtTMn6YA; dkim-atps=neutral; spf=pass (client-ip=2001:41d0:203:375::4d; helo=mta1.migadu.com; envelope-from=hao.ge@linux.dev; receiver=lists.ozlabs.org) smtp.mailfrom=linux.dev Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MtTMn6YA; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=2001:41d0:203:375::4d; helo=mta1.migadu.com; envelope-from=hao.ge@linux.dev; receiver=lists.ozlabs.org) Received: from mta1.migadu.com (out-77.mta1.migadu.com [IPv6:2001:41d0:203:375::4d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4j7Pdf57k9z2yd7 for ; Mon, 19 Oct 2026 16:45:10 +1100 (AEDT) X-Envelope-To: linuxppc-dev@lists.ozlabs.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=1792388692; v=1; x=1792993492; b=MtTMn6YAgt63PiLZWQZLAYe+1kvKxbYndgDbrEc8qmTLzwmksGIoYCwvfdomqqHf5AdbXPsp MTuP30HpnA8fz0bkHTaQW10KP4JWkQkgyDnf1c28sDVJXm5YsgiCcLO0xFkNIwcm3ecF0xQ+ivM KRYhZEargjCrayG58dkxtj8c= X-Envelope-To: linuxppc-dev@lists.ozlabs.org Received: by smtp.migadu.com with ESMTPS id 48f0776ddb594f90; Mon, 19 Oct 2026 05:44:52 +0000 X-Mizu-Trace-ID: 48f0776ddb594f90 X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Suren Baghdasaryan , Uladzislau Rezki , 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 Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Hao Ge Subject: [PATCH v2 5/5] mm/percpu: stop unmapping the CPU that failed to map Date: Mon, 19 Oct 2026 13:45:30 +0800 Message-Id: <20261019054531.87652-6-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20261019054531.87652-1-hao.ge@linux.dev> References: <20261019054531.87652-1-hao.ge@linux.dev> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: 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