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Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaitao Cheng References: <20261028121129.39916-1-kaitao.cheng@linux.dev> From: Kaitao Cheng In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 2CA05100007 X-Stat-Signature: 8ihkmd45z1j6wcj6n94z1g7h11yio8fd X-Rspam-User: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1793247944-151363 X-HE-Meta: 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 wdduxLi1 relzO1Vbv3LhIn0PNDwg9ZtFWhV6imc79CqUNTkVRF4RSBBldfD1rzvU81W/5XCtQXYT9FU209GyUE67WHRhLKkEIosXkxV2cPnq44xux9UT3AlJh/ThSJtYuAamahf/1FRP2PGY94DejG2h2iZWUFN7+cz5z3oQI468dxdgmDjqms0hx0uysu3YSbYzDhKD2OJobj6HwFT7vH8NnK6NyzKibEzeazMQEtFPqe0g8SPzSc4QetrbM6dgC2gwBLk4AQbFJMJ7QzcIJ5KbTy8rmtvl/FgiDfMSx7W7Gn584f7fAMHM= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 在 2026/10/29 00:08, Mike Rapoport 写道: > Hi, > > On Wed, Oct 28, 2026 at 08:11:29PM +0800, Kaitao Cheng wrote: >> From: Kaitao Cheng >> >> sparse_init() is called only once during boot, and the vmemmap alignment >> check is outside any loop, so VM_WARN_ON_ONCE() provides no benefit over >> VM_WARN_ON() here. >> >> Use VM_WARN_ON() and fold compound_info_has_mask() into its condition, >> preserving short-circuit evaluation. > > Do you think it's worth the churn? I think saving two lines of code is nice. It also eliminates a variable, even if only in debug kernels. I’ll send a v2 following Muchun’s suggestion. If the consensus is that this change isn’t worth merging, please feel free to ignore this email. >> Signed-off-by: Kaitao Cheng >> --- >> mm/sparse.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/mm/sparse.c b/mm/sparse.c >> index 6acb628c8a73..248bee2d39b9 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -277,10 +277,8 @@ static void __init sparse_metadata_init(void) >> */ >> void __init sparse_init(void) >> { >> - if (compound_info_has_mask()) { >> - VM_WARN_ON_ONCE(!IS_ALIGNED((unsigned long) pfn_to_page(0), >> - MAX_FOLIO_VMEMMAP_ALIGN)); >> - } >> + VM_WARN_ON(compound_info_has_mask() && !IS_ALIGNED( >> + (unsigned long)pfn_to_page(0), MAX_FOLIO_VMEMMAP_ALIGN)); >> >> sparse_metadata_init(); >> sparse_init_subsection_map(); >> -- >> 2.53.0 >> > -- Thanks Kaitao Cheng