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library: tweak the memory allocation logic, <pids> api

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This patch separates the memory allocations into those
used initially from those used in later reallocations.
Thus, we can reduce that iterative realloc() overhead.

Additionally, we'll correct a long standing oops where
multiple history_info structures were created at 'new'
time when only one should have been allocated (jeeze).

[ originally the allocation was strangely based upon ]
[ number of 'items' (???) & later a #define constant ]

Reference(s):
. May, 2016 - subsequent bad history_info logic
commit 9ebadc1438
. Aug, 2015 - original faulty history_info code
commit 7e6a371d8a

Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is contained in:
Jim Warner 2020-09-30 00:00:00 -05:00 committed by Craig Small
parent 955aaaf732
commit e2b0f8b0af
1 changed files with 21 additions and 11 deletions
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32
proc/pids.c
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@ -49,8 +49,10 @@
//#define UNREF_RPTHASH // report hash details at uref() time
#define FILL_ID_MAX 255 // upper limit with select of pid/uid
#define STACKS_INCR 128 // amount reap stack allocations grow
#define NEWOLD_INCR 128 // amt by which hist allocations grow
#define STACKS_INIT 1024 // amount of initial stack allocation
#define STACKS_GROW 128 // amount reap stack allocations grow
#define NEWOLD_INIT 1024 // amount for initial hist allocation
#define NEWOLD_GROW 128 // amt by which hist allocations grow
/* ------------------------------------------------------------------------- +
this provision can be used to ensure that our Item_table was synchronized |
@ -630,7 +632,7 @@ static inline int pids_make_hist (
HST_t *h;
if (nSLOT + 1 >= Hr(HHist_siz)) {
Hr(HHist_siz) += NEWOLD_INCR;
Hr(HHist_siz) += NEWOLD_GROW;
Hr(PHist_sav) = realloc(Hr(PHist_sav), sizeof(HST_t) * Hr(HHist_siz));
Hr(PHist_new) = realloc(Hr(PHist_new), sizeof(HST_t) * Hr(HHist_siz));
if (!Hr(PHist_sav) || !Hr(PHist_new))
@ -1056,12 +1058,12 @@ static int pids_stacks_fetch (
// initialize stuff -----------------------------------
if (!info->fetch.anchor) {
if (!(info->fetch.anchor = calloc(sizeof(void *), STACKS_INCR)))
if (!(info->fetch.anchor = calloc(STACKS_INIT, sizeof(void *))))
return -1;
if (!(ext = pids_stacks_alloc(info, STACKS_INCR)))
if (!(ext = pids_stacks_alloc(info, STACKS_INIT)))
return -1; // here, errno was set to ENOMEM
memcpy(info->fetch.anchor, ext->stacks, sizeof(void *) * STACKS_INCR);
n_alloc = STACKS_INCR;
memcpy(info->fetch.anchor, ext->stacks, sizeof(void *) * STACKS_INIT);
n_alloc = STACKS_INIT;
}
pids_toggle_history(info);
memset(&info->fetch.counts, 0, sizeof(struct pids_counts));
@ -1070,11 +1072,11 @@ static int pids_stacks_fetch (
n_inuse = 0;
while (info->read_something(info->fetch_PT, &task)) {
if (!(n_inuse < n_alloc)) {
n_alloc += STACKS_INCR;
n_alloc += STACKS_GROW;
if (!(info->fetch.anchor = realloc(info->fetch.anchor, sizeof(void *) * n_alloc))
|| (!(ext = pids_stacks_alloc(info, STACKS_INCR))))
|| (!(ext = pids_stacks_alloc(info, STACKS_GROW))))
return -1; // here, errno was set to ENOMEM
memcpy(info->fetch.anchor + n_inuse, ext->stacks, sizeof(void *) * STACKS_INCR);
memcpy(info->fetch.anchor + n_inuse, ext->stacks, sizeof(void *) * STACKS_GROW);
}
if (!pids_proc_tally(info, &info->fetch.counts, &task))
return -1; // here, errno was set to ENOMEM
@ -1164,11 +1166,19 @@ PROCPS_EXPORT int procps_pids_new (
pids_libflags_set(p);
}
if (!(p->hist = calloc(NEWOLD_INCR, sizeof(struct history_info)))) {
if (!(p->hist = calloc(1, sizeof(struct history_info)))
|| (!(p->hist->PHist_new = calloc(NEWOLD_INIT, sizeof(HST_t))))
|| (!(p->hist->PHist_sav = calloc(NEWOLD_INIT, sizeof(HST_t))))) {
free(p->items);
if (p->hist) {
free(p->hist->PHist_sav); // this & next might be NULL ...
free(p->hist->PHist_new);
free(p->hist);
}
free(p);
return -ENOMEM;
}
p->hist->HHist_siz = NEWOLD_INIT;
pids_config_history(p);
pgsz = getpagesize();