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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5359b79a186sm41486481cf.20.2026.10.10.07.26.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 10 Oct 2026 07:26:35 -0700 (PDT) Date: Sat, 10 Oct 2026 10:26:33 -0400 From: Gregory Price To: albin_yang@163.com Cc: akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, david@kernel.org, vbabka@kernel.org, jannh@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, albinwyang@tencent.com Subject: Re: [PATCH] mm/madvise: add cond_resched() in THP branch of madvise_cold_or_pageout_pte_range() Message-ID: References: <20261010024042.4070048-1-albin_yang@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261010024042.4070048-1-albin_yang@163.com> On Sat, Oct 10, 2026 at 10:40:42AM +0800, albin_yang@163.com wrote: > From: Wei Yang > > Crash log: > watchdog: BUG: soft lockup - CPU#63 stuck for 23s! [stress-ng-vm:1665914] > ... > Call trace: > pmdp_invalidate+0x48/0x68 > madvise_cold_or_pageout_pte_range+0x84c/0xb00 > walk_pmd_range.isra.0+0x1ac/0x3b0 > walk_pud_range+0x120/0x190 > walk_pgd_range+0x170/0x1b8 > __walk_page_range+0x184/0x198 > walk_page_range_vma+0x94/0x128 > madvise_cold+0xd8/0x198 > madvise_vma_behavior+0x234/0x638 > madvise_walk_vmas.constprop.0+0xdc/0x210 > madvise_do_behavior+0xa8/0x328 > do_madvise+0xd8/0x140 > __arm64_sys_madvise+0x2c/0xe0 > > Signed-off-by: Wei Yang > --- > mm/madvise.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/madvise.c b/mm/madvise.c > index eeee82cf2b3f..0755e6d99757 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -450,6 +450,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > spin_unlock(ptl); > if (pageout) > reclaim_pages(&folio_list); > + cond_resched(); > return 0; > } > This same improvement came naturally from refactoring the entire function into a proper pagewalk structure: https://lore.kernel.org/linux-mm/20260922235830.2350770-10-gourry@gourry.net/ this function is really nasty. ~Gregory