"Eric Paris" <eparis@xxxxxxxxxxxxxx> wrote: > On Tue, May 20, 2008 at 12:13 PM, Jim Meyering <jim@xxxxxxxxxxxx> wrote: >> Stephen Smalley <sds@xxxxxxxxxxxxx> wrote: >> ... >>> This issue came up recently again, see: >>> https://bugzilla.redhat.com/show_bug.cgi?id=447410 >>> >>> It appears that the patch that was merged into coreutils ends up calling >>> matchpathcon_init_prefix() for each file being installed rather than >>> once upon startup, and without calling matchpathcon_fini() to free the >>> memory allocated by each matchpathcon_init_prefix() call. >>> >>> That makes it slower than necessary and leaks memory. >>> >>> See the bug report for the discussion. >>> >>> Can we get this corrected in the upstream coreutils? Thanks. >> >> Thanks for letting me know. The patch below should do the job. >> I didn't bother calling matchpathcon_fini, since its 6MB buffer >> is still reachable. >> >> For now, I'm leaving that code ifdef'd out, because the performance >> penalty is still too high even on rawhide, when performing a few hundred >> to a thousand separate install commands (about a 20x hit, when >> installing to /usr). For reference, I did this: >> >> # matchpathcon code all ifdef'd out: >> $ touch k; time ( for i in $(seq 200); do; install k /usr/tmp/k ;done ) >> 0.08s user 0.30s system 97% cpu 0.391 total >> # matchpathcon code in use: >> $ touch k; time ( for i in $(seq 200); do; ./ginstall k /usr/tmp/k ;done ) >> 7.19s user 1.62s system 99% cpu 8.840 total > > Just wondering, how much was the perf penalty before this patch? For the single-file case, the patch I pushed makes no performance difference (assuming the if-0'd code is enabled), since matchpathcon is called only once. In the multi-file case, the pre-patch performance penalty for enabling the ifdef'd-out code would range from probably-immeasurable (for just 2 or 3 files) to infinite, with enough files to make install exhaust virtual memory. -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
