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s=arc-20220608; t=1717121225; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4Jw89+wU5dNyUegU7ptpj0btuafoXZ+lFLT+MT19m2w=; b=zouOG5SgTfcJdqIakok5hyfsMFavTjN14/bI5ggTIor6vhAN5KUd57FTB2rx5HuIotsv2V QeuvJcaI4/nb7oThw70mtD5ukADfQxS4FBMwxCSHBO+jLoW2Jn7k06uhQm2ADac27ohCi7 T/mCWsgAM3DyTmVvgjYuOli8uR3bFyg= X-AuditID: a67dfc5b-d6dff70000001748-3a-665930c4cb00 Date: Fri, 31 May 2024 11:06:54 +0900 From: Byungchul Park To: Dave Hansen Cc: "Huang, Ying" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, akpm@linux-foundation.org, vernhao@tencent.com, mgorman@techsingularity.net, hughd@google.com, willy@infradead.org, david@redhat.com, peterz@infradead.org, luto@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, rjgolo@gmail.com Subject: Re: [PATCH v10 00/12] LUF(Lazy Unmap Flush) reducing tlb numbers over 90% Message-ID: <20240531020654.GA62639@system.software.com> References: <8734q46jc8.fsf@yhuang6-desk2.ccr.corp.intel.com> <44e4f2fd-e76e-445d-b618-17a6ec692812@intel.com> <20240529050046.GB20307@system.software.com> <961f9533-1e0c-416c-b6b0-d46b97127de2@intel.com> <20240530005026.GA47476@system.software.com> <87a5k814tq.fsf@yhuang6-desk2.ccr.corp.intel.com> <20240530071847.GA15344@system.software.com> <871q5j1zdf.fsf@yhuang6-desk2.ccr.corp.intel.com> <20240530084120.GA12940@system.software.com> <2a0f8cc9-a061-45cd-81df-b65d4b454b77@intel.com> MIME-Version: 1.0 Content-Type: text/plain; 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Ying and I see a problem that we've > tried to explain a couple of times. We've tried to show the connection > between a LUF-elided TLB flush and how that could affect a later > munmap() or mmap(MAP_FIXED). > > But these responses seem to keep going back to the fact that LUF doesn't I just wanted to understand exactly what Ying meant. My answer might be done in a wrong way if I wrongly got him. > directly affect munmap(), which is true, but quite irrelevant to the > problem being described. > > So we're at an impasse. > > Byungchul, perhaps you should spin another series and maybe Ying and I I don't think the current implementation is perfect. I just wanted to know what I'm missing now but.. yes. It would be much better to communicate with a real bug if existing. I will respin the next version shortly. Byungchul > have to write up a test case to show the bug that we see. Or perhaps > someone else can jump into the thread and bridge the communication gap.