| Main Device Driver Logging khttpd NUMA PCI Hotplug PPC32 SCTP Security Modules Sound Token Ring USAGI USB |
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| vectored raw I/O performance improvement | |
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Description: The patch improves the performance of vectored raw I/O by combining the iovecs passed by a readv/writev call into a single kiobuf and issuing one call to brw_kiovec to submit the io. Without the patch, the readv/writev system calls (effectively) serially invoke the read/write system calls for each iovec. With the patch applied, raw readv/writev approximates the speed of a read/write for the aggregate iov_len's (rather than vectored I/O running 2 or 3 times slower). In preliminary DB2 testing, the time for a single tablescan was reduced from 621 seconds to 172 seconds with the patch applied. |
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| Developers: Badari Pulavarty, Janet Morgan, Shailabh Nagar |
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| Status: Submitted to project |
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| Release | Notes | Date | Files |
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| 2.4.17 | Release Notes | 2002-02-07 | |
| File Notes | vector_io-2.4.17.patch.gz |