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AJvYcCW9RokYFC/KXIZPYO85YqlJ3bBzpPQgDtPK3UDSik5k1boRvfoK9Z0wD5TEEQLmTzeMI70S1JAhJA==@kvack.org X-Gm-Message-State: AOJu0YwJIS1GRgotab3vwoZXUvykz7qHGVGhBE/X/wQRvip4SuR1XUfN aXsUMpfS2OEvzoj1uG7I4+dnsIYAbMVsw4fRd0Y4FqnSZZ9HZE0CiIIRhGXkyS1c2Yn9q/Xpewc 3lQmmPYABq/mu2sG3gRe5ES/6ZTfqutc= X-Gm-Gg: ASbGncsSLx+SQAW+svthn43cAPTgWNvKNfnL0r/AsfRmmQyYVDwUhpecI2nXZa8VDre 1s/8nnuOkWPkdmDoQawprnpGF0+JM8n99VwV5rorbZ3rJ9uc2+z9hQmZLD+Ykjuv5HXTWeYPfD2 BfgkVXPIEbcZ7UnBW3F2Xd5SDjlSCurpl9FdJeuDY8YvEUqoVqqDD5XLtCa4gD3tcgLIYzz8JP6 PZmLtq+ZkeMJbaFTn7qMQEuOyo318qiUBnTcRtF X-Google-Smtp-Source: AGHT+IEJAG2qKNzxlah6l/w2L3/KsxC8SauReCHdhKHjO7bLzRLIuTYZp5EjbFuJL94qP6L3iBxwYtkrnQTe9YDl6e8= X-Received: by 2002:ad4:4f09:0:b0:70d:9b08:8df4 with SMTP id 6a1803df08f44-70d9b089047mr125928626d6.67.1756210280301; Tue, 26 Aug 2025 05:11:20 -0700 (PDT) MIME-Version: 1.0 References: <20250826071948.2618-1-laoar.shao@gmail.com> In-Reply-To: From: Yafang Shao Date: Tue, 26 Aug 2025 20:10:43 +0800 X-Gm-Features: Ac12FXzZZhivnVJyBOI8iejkd_haUHtgHc6xuPfqezPTB1X-J44KnLBSJW6VTiM Message-ID: Subject: Re: [PATCH v6 mm-new 00/10] mm, bpf: BPF based THP order selection To: Usama Arif Cc: David Hildenbrand , akpm@linux-foundation.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, hannes@cmpxchg.org, gutierrez.asier@huawei-partners.com, willy@infradead.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, ameryhung@gmail.com, rientjes@google.com, corbet@lwn.net, bpf@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 6AF1480008 X-Stat-Signature: tjrs77qr8psep7w6hoonq8krk31ysnuj X-Rspam-User: X-HE-Tag: 1756210281-987881 X-HE-Meta: U2FsdGVkX1+NqPe2YlTm2zdWEFmQ6FAGQF25dZQvcVI1OvWzBHnEtmUrBwwItp5TCnaKo2BMb7oc7rEZoN+Ev7hJEaIWJcLRCQ9jYHXPur0scPwS+zyQ4hoNWquGWl25Q2uPicO62pfpvpxG4xFbE3sIFLjJ92uo1u0/PjVFe4GW88PB7Jjyrk+Gq2nYTu2TIMQoaX13gd07GxiFyCEYNlqg3M1ClAWoiIUrikcIS6e5xys1AL2N7IBtZjKf00tgltp7covOok+5uCSIYk2Bn4UrK37POHyN78YHuOsKEbz5xf26jSeZuYo9JzyzFL44idPGmCpOeFMBXPpV2C5UP1SnCTxSceQAT91phnY+Ma6kDIzBxzLoXmdQ/8uQki3ruMW6ftOHflbyaCrh61icIdeE9q8LNLPncMJlE1GkEeMEipGdmYru1BvjqCD0YC8TiREPlwM9DDq4uVBYvAdJ+5ttfrjS6CyEsRxh6aP1YInwePnNPqmuAN+3BJTM5JFV4Mdz0u0x3CRxr1s3uShPRbLqAJsmHbRyAcNmYzwbK8sndOmfcP8NA5Fo0W/SbDyTlIohjjDiwRq69bp+Em8i7d6si3tALyDTMMHLnGHCmTa9Iyk8ZsD6HBBtpltgVEmUviSUI3LjRVap0gKtnXfaoBWfQjsZ1XpnuIVQipIlFBIrKtoGZiRq9a9Nt6BK2HYKMWAHbHRwFw2IQJYiyrLTXMF2Au5pMWR281YVYg+r+oe5S6X3e48L83O2+B1MoP81EnotcZt6S3E/E2cwZnDYG5sYTXtGdregqU1Zr0hmDoOMPHLF1vIyrOcHqy06FDQxJ3fVDyK5+Ds+wzbTBEWQb+uBWxv968k/ta9IJAZ1wQrltTKBAwkKH0XGwZOPiHSKbnIv0wdRDLlwmpgyR+DToaE2Fa0DXWYucW/r70cQUC5a03UZWQD/8Iv8ygDgsrChJICyyFkvqB2VBH/9s6X UefAck+n JfsN34lyQ6s7j+JTOVGvJDvvqsfj9TJMete2xkaerdcqhJ2F7hPfdumV4vYJXkneuH3VYa/HiqHlzjrTIdtI+Jm2EV75Nu9Xe//dCI5+TYEN5mRyvk7eDpzibe9qkX7a6Ct3pPjGZB/LubTaBDzhnG/R3P12HyiUnmFejVIAeqDN9/OQGQ77eY/KqVBOWxFcZOPbDZMHr1aPdVSnVe74AkOjirmbn3zaI6Rcpf1hlwz/lvfHOGpE4okl+t45EDRVVJEno/+IezsB64bWjC9O+ezhC04dkhuG5FAx4szzskL3CnBFFH7nu3MYPIzSxRLuiBSN3mi8pONHvNSIk7evVTCqBbiLJmg5kBaYXNh/rgXVwvYebK80heIyz9/qYrGBICG1pJQFYQMPGsLFgZXsYREcaQLH8ErGxzuK4 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Aug 26, 2025 at 5:52=E2=80=AFPM Usama Arif = wrote: > > > > On 26/08/2025 08:42, David Hildenbrand wrote: > > On 26.08.25 09:19, Yafang Shao wrote: > >> Background > >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > >> > >> Our production servers consistently configure THP to "never" due to > >> historical incidents caused by its behavior. Key issues include: > >> - Increased Memory Consumption > >> THP significantly raises overall memory usage, reducing available m= emory > >> for workloads. > >> > >> - Latency Spikes > >> Random latency spikes occur due to frequent memory compaction trigg= ered > >> by THP. > >> > >> - Lack of Fine-Grained Control > >> THP tuning is globally configured, making it unsuitable for contain= erized > >> environments. When multiple workloads share a host, enabling THP wi= thout > >> per-workload control leads to unpredictable behavior. > >> > >> Due to these issues, administrators avoid switching to madvise or alwa= ys > >> modes=E2=80=94unless per-workload THP control is implemented. > >> > >> To address this, we propose BPF-based THP policy for flexible adjustme= nt. > >> Additionally, as David mentioned [0], this mechanism can also serve as= a > >> policy prototyping tool (test policies via BPF before upstreaming them= ). > > > > There is a lot going on and most reviewers (including me) are fairly bu= sy right now, so getting more detailed review could take a while. > > > > This topic sounds like a good candidate for the bi-weekly MM alignment = session. > > > > Would you be interested in presenting the current bpf interface, how to= use it, drawbacks, todos, ... in that forum? > > > > Could I get an invite please? Thanks! IIUC, a Google Meet link will be shared publicly on the upstream mailing list, allowing any interested developers to join. If the session is invite-only instead, I will make sure you receive an invitation, given the significant help you've already provided for this series. --=20 Regards Yafang