Date: Thu, 4 Jan 2018 22:07:59 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r327562 - head/sys/kern Message-ID: <201801042207.w04M7xnC003536@repo.freebsd.org>
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Author: jhb Date: Thu Jan 4 22:07:58 2018 New Revision: 327562 URL: https://svnweb.freebsd.org/changeset/base/327562 Log: Always use atomic_fetchadd() when updating per-user accounting values. This avoids re-reading a variable after it has been updated via an atomic op. It is just a cosmetic cleanup as the read value was only used to control a diagnostic printf that should rarely occur (if ever). Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D13768 Modified: head/sys/kern/kern_resource.c Modified: head/sys/kern/kern_resource.c ============================================================================== --- head/sys/kern/kern_resource.c Thu Jan 4 21:59:34 2018 (r327561) +++ head/sys/kern/kern_resource.c Thu Jan 4 22:07:58 2018 (r327562) @@ -1384,18 +1384,17 @@ ui_racct_foreach(void (*callback)(struct racct *racct, static inline int chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name) { + long new; /* Don't allow them to exceed max, but allow subtraction. */ + new = atomic_fetchadd_long(limit, (long)diff) + diff; if (diff > 0 && max != 0) { - if (atomic_fetchadd_long(limit, (long)diff) + diff > max) { + if (new < 0 || new > max) { atomic_subtract_long(limit, (long)diff); return (0); } - } else { - atomic_add_long(limit, (long)diff); - if (*limit < 0) - printf("negative %s for uid = %d\n", name, uip->ui_uid); - } + } else if (new < 0) + printf("negative %s for uid = %d\n", name, uip->ui_uid); return (1); }
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