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Microoptimize corner case of ID bitmap handling.

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Prior to the change we would avoidably test more possibly used IDs.

While here update the comment: there is no pidchecked variable anymore.
This commit is contained in:
mjg 2018-12-19 20:29:52 +00:00
parent 94437ac557
commit 655bf8e58a
1 changed files with 7 additions and 8 deletions
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15
sys/kern/kern_fork.c
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@ -238,19 +238,18 @@ extern bitstr_t proc_id_grpidmap;
extern bitstr_t proc_id_sessidmap;
extern bitstr_t proc_id_reapmap;
/*
* Find an unused process ID
*
* If RFHIGHPID is set (used during system boot), do not allocate
* low-numbered pids.
*/
static int
fork_findpid(int flags)
{
pid_t result;
int trypid;
/*
* Find an unused process ID. We remember a range of unused IDs
* ready to use (from lastpid+1 through pidchecked-1).
*
* If RFHIGHPID is set (used during system boot), do not allocate
* low-numbered pids.
*/
trypid = lastpid + 1;
if (flags & RFHIGHPID) {
if (trypid < 10)
@ -280,7 +279,7 @@ retry:
if (bit_test(&proc_id_grpidmap, result) ||
bit_test(&proc_id_sessidmap, result) ||
bit_test(&proc_id_reapmap, result)) {
trypid++;
trypid = result + 1;
goto retry;
}