Author: gallatin Date: Mon Jul 31 14:56:35 2017 New Revision: 321790 URL: https://svnweb.freebsd.org/changeset/base/321790
Log: Don't request CTLTYPE_OPAQUE if we can't print them. The intent is to skip expensive opaque sysctls like tcp_pcblist unless they are explicitly requested. Sysctl nodes like this don't show up in sysctl -a, but they do generate output that winds up being dropped, unless the user specifically requested binary/hex output or opaques. This reduces the runtime of sysctl in many circumstances on a loaded system. It also reduces the likelihood that simply gathering diagnostics on a sick machine (stuck lock, etc) via sysctl -a might push it over the edge into a total lockup. Reviewed by: jtl Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D11461 Modified: head/sbin/sysctl/sysctl.c Modified: head/sbin/sysctl/sysctl.c ============================================================================== --- head/sbin/sysctl/sysctl.c Mon Jul 31 14:53:03 2017 (r321789) +++ head/sbin/sysctl/sysctl.c Mon Jul 31 14:56:35 2017 (r321790) @@ -925,6 +925,32 @@ show_var(int *oid, int nlen) printf("%s", buf); return (0); } + + /* don't fetch opaques that we don't know how to print */ + if (ctltype == CTLTYPE_OPAQUE) { + if (strcmp(fmt, "S,clockinfo") == 0) + func = S_clockinfo; + else if (strcmp(fmt, "S,timeval") == 0) + func = S_timeval; + else if (strcmp(fmt, "S,loadavg") == 0) + func = S_loadavg; + else if (strcmp(fmt, "S,vmtotal") == 0) + func = S_vmtotal; +#ifdef __amd64__ + else if (strcmp(fmt, "S,efi_map_header") == 0) + func = S_efi_map; +#endif +#if defined(__amd64__) || defined(__i386__) + else if (strcmp(fmt, "S,bios_smap_xattr") == 0) + func = S_bios_smap_xattr; +#endif + else { + func = NULL; + if (!bflag && !oflag && !xflag) + return (1); + } + } + /* find an estimate of how much we need for this var */ if (Bflag) j = Bflag; @@ -1045,24 +1071,6 @@ show_var(int *oid, int nlen) case CTLTYPE_OPAQUE: i = 0; - if (strcmp(fmt, "S,clockinfo") == 0) - func = S_clockinfo; - else if (strcmp(fmt, "S,timeval") == 0) - func = S_timeval; - else if (strcmp(fmt, "S,loadavg") == 0) - func = S_loadavg; - else if (strcmp(fmt, "S,vmtotal") == 0) - func = S_vmtotal; -#ifdef __amd64__ - else if (strcmp(fmt, "S,efi_map_header") == 0) - func = S_efi_map; -#endif -#if defined(__amd64__) || defined(__i386__) - else if (strcmp(fmt, "S,bios_smap_xattr") == 0) - func = S_bios_smap_xattr; -#endif - else - func = NULL; if (func) { if (!nflag) printf("%s%s", name, sep); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
