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![]() Fault in the buffer prior to writing to workaround poor performance due to interaction with kernel fs deadlock avoidance code. See the comment prior to vn_io_fault_doio() in sys/kern/vfs_vnops.c for details of the issue. On my stable/10 desktop with a 16MB obj.o and "ar r out.a obj.o" I see the following run times (seconds): x ar.r284891 + ar.patched +----------------------------------------------------------------------+ |+ | |+ x| |+ xx| |A |A| +----------------------------------------------------------------------+ N Min Max Median Avg Stddev x 3 1.307 1.321 1.315 1.3143333 0.0070237692 + 3 0.020 0.023 0.022 0.021666667 0.0015275252 Difference at 95.0% confidence -1.29267 +/- 0.0115203 -98.3515% +/- 0.876513% (Student's t, pooled s = 0.00508265) Thanks to kib for diagnosing and explaining the issue and suggesting the workaround. Reviewed by: eadler, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D2933 |
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acplex.l | ||
acpyacc.y | ||
ar.1 | ||
ar.c | ||
ar.h | ||
Makefile | ||
Makefile.depend | ||
read.c | ||
util.c | ||
write.c |