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[209.85.218.41]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a72aaf6336csm449249766b.70.2024.07.02.13.43.05 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Jul 2024 13:43:05 -0700 (PDT) Received: by mail-ej1-f41.google.com with SMTP id a640c23a62f3a-a7245453319so737625466b.1 for ; Tue, 02 Jul 2024 13:43:05 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCUQInqOshSgLzETDz2SVFrOeM+r9fRzWL8x97OL51gRjW5oy9trA5G//ys1xpHZtmMln+A7uzsE/3VHU1NRLSUTuuA= X-Received: by 2002:a17:906:eb4c:b0:a6f:935b:8777 with SMTP id a640c23a62f3a-a72aefa5ab3mr919607766b.25.1719952985057; Tue, 02 Jul 2024 13:43:05 -0700 (PDT) MIME-Version: 1.0 References: <202406270912.633e6c61-oliver.sang@intel.com> <3g3arsrwnyvv562v2rsfv2ms4ht4mk45vwdkvssxkrjhfjtpdz@umyx5tl2du7o> In-Reply-To: <3g3arsrwnyvv562v2rsfv2ms4ht4mk45vwdkvssxkrjhfjtpdz@umyx5tl2du7o> From: Linus Torvalds Date: Tue, 2 Jul 2024 13:42:48 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [linux-next:master] [lockref] d042dae6ad: unixbench.throughput -33.7% regression To: Mateusz Guzik Cc: Christian Brauner , kernel test robot , oe-lkp@lists.linux.dev, lkp@intel.com, Linux Memory Management List , linux-kernel@vger.kernel.org, ying.huang@intel.com, feng.tang@intel.com, fengwei.yin@intel.com Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: k1p339i7an6ab9qc46mpoidytotcrp5a X-Rspamd-Queue-Id: DDD80180016 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1719952987-684899 X-HE-Meta: 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 56fEoEur 400pTD82ZX+HrBkYk7MmBL6MXoZ3qc88wRJas0KX8+bjWL1zUzR3j927yuw2ubbGgfbwUv4IdCQbUj3d+FInU+/xQxmsXct38r0r6LbWvdhP0W2+ibpV38CwxT5A3chc5QctEm/XtyFgurGVgLabpTHSvYlfww6Bo4xb8lMk69tRZABpb8UckZuZ3chYrc1/YEnROlTiLiSavP4Zq56VVhZZoQU14c6mB/SD6baiIgFop8ycKKgISnqYsoBmc3oV2LiovKHjlI6+CUtjpy8c9SXKY5el+uqaYgDeJmzL4sbVHUUiJTUnM77zmXW6T37XWDVIws/H5bvwJyoP4O7Z9SFRsmBqiz2BfGCv9Ohm4BYbtuWjuIeNB9qSFXMTbyvD+PE4yy00tnpbTetWcce68eEnyZkooasnWclN7R2muNwr7SNkUw0LSOsyRxPoc1kQeGS0gdIoXaEycALT024s7T8UuCEkl4ECOONR9 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, 2 Jul 2024 at 13:33, Mateusz Guzik wrote: > > If you are politely by lkml standards suggesting I should probably drop > the idea due to unforseen complexities Oh, absolutely not. I'd love to see how nasty - or not nasty - the patch would end up being. I think it would be very interesting. I'm just explaining why _I_ never got around to it. I do think that the 'stat()' family of syscalls are some of the most critical system calls out there. And while I suspect the benchmarks that stat the same file over and over in parallel are worthless, if we can do 'stat()' without ever even dirtying the dentry at all, that would be absolutely lovely. Linus