Messages in this thread | | | Date | Thu, 10 Oct 2002 00:23:49 +0200 | From | "J.A. Magallon" <> | Subject | More on O_STREAMING (goodby read pauses) |
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Hi all...
I have discovered one other (good) side effect of O_STREAMING.
I tested it on my duap PII@400, ~900Mb RAM.
Timings:
Without O_STREAMING: 0.00user 10.13system 0:41.16elapsed 24%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (81major+2574minor)pagefaults 0swaps With O_STREAMING: 0.00user 11.03system 0:40.06elapsed 27%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (81major+2574minor)pagefaults 0swaps
Memory:
Before total: used: free: shared: buffers: cached: Mem: 926797824 228376576 698421248 0 20729856 95637504 Swap: 353644544 114688 353529856 MemTotal: 905076 kB MemFree: 682052 kB MemShared: 0 kB Buffers: 20244 kB Cached: 93284 kB SwapCached: 112 kB Active: 77284 kB Inactive: 97160 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 905076 kB LowFree: 682052 kB SwapTotal: 345356 kB SwapFree: 345244 kB BigFree: 0 kB
After test without O_STREAMING: total: used: free: shared: buffers: cached: Mem: 926797824 910376960 16420864 0 13369344 788623360 Swap: 353644544 1077248 352567296 MemTotal: 905076 kB MemFree: 16036 kB MemShared: 0 kB Buffers: 13056 kB Cached: 769088 kB SwapCached: 1052 kB Active: 83672 kB Inactive: 759388 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 905076 kB LowFree: 16036 kB SwapTotal: 345356 kB SwapFree: 344304 kB BigFree: 0 kB
After test with O_STREAMING: total: used: free: shared: buffers: cached: Mem: 926797824 228241408 698556416 0 20647936 95596544 Swap: 353644544 114688 353529856 MemTotal: 905076 kB MemFree: 682184 kB MemShared: 0 kB Buffers: 20164 kB Cached: 93244 kB SwapCached: 112 kB Active: 77200 kB Inactive: 97112 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 905076 kB LowFree: 682184 kB SwapTotal: 345356 kB SwapFree: 345244 kB BigFree: 0 kB
But I did the test with an addition: read a 1Gb file and print an '*' after every 10M. Without O_STREAMING, when memory fills, the 'progress bar' stalls for a few seconds while pages are sent to disk. So the patch also favours a constant sustained rate of read from the disk. Very interesting for things like video edition and so on. I like it ;).
Thanks.
-- J.A. Magallon <jamagallon@able.es> \ Software is like sex: werewolf.able.es \ It's better when it's free Mandrake Linux release 9.1 (Cooker) for i586 Linux 2.4.20-pre10-jam1 (gcc 3.2 (Mandrake Linux 9.0 3.2-2mdk)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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