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McKenney" , Waiman Long , Al Viro , LKML Subject: Re: performance delta after VFS i_mutex=>i_rwsem conversion References: <5755D671.9070908@intel.com> <5755E782.90800@hpe.com> <77052.1465269772@turing-police.cc.vt.edu> In-Reply-To: <77052.1465269772@turing-police.cc.vt.edu> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [71.168.64.186] X-ClientProxiedBy: CO2PR18CA0020.namprd18.prod.outlook.com (10.161.80.30) To CS1PR84MB0310.NAMPRD84.PROD.OUTLOOK.COM (10.162.190.28) X-MS-Office365-Filtering-Correlation-Id: b8f8486d-7bfb-40e7-613f-08d38ee796f2 X-Microsoft-Exchange-Diagnostics: 1;CS1PR84MB0310;2:NdaJ2e/etfwMpT3eNblgBRcglD1cRbwgxB1+iLSvY0lOqhGWDvWM8X2dBkIqbHyU5NAXSx4JqfDcy0imZMVeAB/NA5WUN29VT8V4fjV/J2cJcpYBXABHYmSve6KHOIR0X+6mf5V78Txo0TXNnejoGLMq/OAiKTCZMjvvZKcWYTvpdbihSOZe844RcCkFxY30;3:/9sQkHHB4cyt+qeEodkoI9ygfhkWtWIBeywQT1auImwxNbFpJB4Y8BBmktEwZjjg3zEvY4Uw1Ev9MeEdYxJMOUeAyruLs9tc5Rz2Un0d/GqTzlLf9lEYyfwgLYjUsWhp;25:+3xb2Hx2bp3/JCpusvJacgYQlNE49hTiQ2A2VYRN3jWgCUpd1Rj15l47ytQfAMLWZJ5Dptwrwviy1Ckl8rXcj87mjh1L0waC0OdV1EW0Q2D5OnfpNENo/hAMJ0RtrTWCAzGGxH5r2XTMYvOdKQkzcauev0EPfr70FZgiRA2ZXUBSp+rlCRpmzH813F2ZjExoIvz2bBs7uf5+35cDuvFn3RmTdxN4ycvHc7biIGz27a3o3Peshpn5FS792C0MCCqGBkmyZBhXDtL5Uuh9wyolzXokJ9KyqPVihrQ+PmiRZOO+f4Yq0PtxK1nfXyUnt2OsIhgQs/SVpw7DLci2h5FrysDk9TAYwwY5KqiptmMuzugTnHinFVcc75QMRImK9cptambJpVDbBf2kR4eVvfExQpO3YwQzHOn90OwWTB/2BW4= X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CS1PR84MB0310; 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No idea. Let's not worry about it too >> much until somebody shows a reason to worry. > I've seen Makefiles where 'make clean' does a 'find . -name "*.o" | xargs rm'. > > But if somebody is doing that often enough against cache-cold directory trees > to matter, they have bigger problems (like learning how to properly develop > code using 'make'). So unless performance is *so* bad it triggers the lockup > detector, it's probably OK.... > The performance won't be very bad. It is just that with the right mix of readers and writers, the performance can be a bit worse with i_rwsem than with i_mutex. But in other cases, the performance will be comparable or better with i_rwsem. Regards, Longman