Date: Sat, 25 Apr 2015 15:43:13 +0000 (UTC) From: Robert Watson <rwatson@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r281983 - head/sys/cddl/dev/profile Message-ID: <201504251543.t3PFhDFZ081455@svn.freebsd.org>
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Author: rwatson Date: Sat Apr 25 15:43:12 2015 New Revision: 281983 URL: https://svnweb.freebsd.org/changeset/base/281983 Log: Adjust PROF_ARTIFICIAL_FRAMES in the DTrace profile provider on ARM to skip 10, rather than 9, frames. This appears to work quite well in practice on the BeagleBone Black, so remove a comment about the value being bogus and replace it with a slightly less negative one. However, the number of frames to skip is quite sensitive to details of the timer and interrupt handling paths, so this is necessarily fragile -- but no more so than on x86. Sponsored by: DARPA, AFRL Modified: head/sys/cddl/dev/profile/profile.c Modified: head/sys/cddl/dev/profile/profile.c ============================================================================== --- head/sys/cddl/dev/profile/profile.c Sat Apr 25 13:34:25 2015 (r281982) +++ head/sys/cddl/dev/profile/profile.c Sat Apr 25 15:43:12 2015 (r281983) @@ -134,8 +134,10 @@ struct profile_probe_percpu; #endif #ifdef __arm__ -/* bogus */ -#define PROF_ARTIFICIAL_FRAMES 9 +/* + * At least on ARMv7, this appears to work quite well. + */ +#define PROF_ARTIFICIAL_FRAMES 10 #endif typedef struct profile_probe {
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