From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Subject: [PATCH v3] elf: Use C11 atomics on _dl_mcount
Date: Tue, 20 Sep 2022 16:04:13 -0300 [thread overview]
Message-ID: <20220920190413.3160597-1-adhemerval.zanella@linaro.org> (raw)
All atomic operation are counters, so relaxed MO should be suffice.
Checked on x86_64-linux-gnu.
---
elf/dl-profile.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/elf/dl-profile.c b/elf/dl-profile.c
index ec57e3a965..c5ac9b5a3e 100644
--- a/elf/dl-profile.c
+++ b/elf/dl-profile.c
@@ -548,7 +548,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
size_t newfromidx;
to_index = (data[narcs].self_pc
/ (HASHFRACTION * sizeof (*tos)));
- newfromidx = catomic_exchange_and_add (&fromidx, 1) + 1;
+ newfromidx = atomic_fetch_add_relaxed (&fromidx, 1) + 1;
froms[newfromidx].here = &data[narcs];
froms[newfromidx].link = tos[to_index];
tos[to_index] = newfromidx;
@@ -558,14 +558,14 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
/* If we still have no entry stop searching and insert. */
if (*topcindex == 0)
{
- unsigned int newarc = catomic_exchange_and_add (narcsp, 1);
+ unsigned int newarc = atomic_fetch_add_relaxed (narcsp, 1) + 1;
/* In rare cases it could happen that all entries in FROMS are
occupied. So we cannot count this anymore. */
if (newarc >= fromlimit)
goto done;
- *topcindex = catomic_exchange_and_add (&fromidx, 1) + 1;
+ *topcindex = atomic_fetch_add_relaxed (&fromidx, 1) + 1;
fromp = &froms[*topcindex];
fromp->here = &data[newarc];
@@ -573,7 +573,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
data[newarc].self_pc = selfpc;
data[newarc].count = 0;
fromp->link = 0;
- catomic_increment (&narcs);
+ atomic_fetch_add_relaxed (&narcs, 1);
break;
}
@@ -586,7 +586,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
}
/* Increment the counter. */
- catomic_increment (&fromp->here->count);
+ atomic_fetch_add_relaxed (&fromp->here->count, 1);
done:
;
--
2.34.1
next reply other threads:[~2022-09-20 19:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 19:04 Adhemerval Zanella [this message]
2022-09-20 22:59 ` Wilco Dijkstra
2022-09-21 14:01 ` Adhemerval Zanella Netto
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