From b84af9b499891f250637eabb0837f3ae31be353e Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Mon, 22 Mar 2021 12:24:26 -0400
Subject: [PATCH] add wrapper for madvise

---
 h_malloc.c | 4 ++--
 memory.c   | 8 ++++++++
 memory.h   | 1 +
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/h_malloc.c b/h_malloc.c
index d5daf64..d25c37a 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -1773,7 +1773,7 @@ EXPORT int h_malloc_trim(UNUSED size_t pad) {
                 for (size_t i = 0; i < slab_quarantine_random_length; i++) {
                     void *p = c->quarantine_random[i];
                     if (p != NULL) {
-                        madvise(p, size, MADV_DONTNEED);
+                        memory_purge(p, size);
                     }
                 }
 #endif
@@ -1783,7 +1783,7 @@ EXPORT int h_malloc_trim(UNUSED size_t pad) {
                 for (size_t i = 0; i < slab_quarantine_queue_length; i++) {
                     void *p = c->quarantine_queue[i];
                     if (p != NULL) {
-                        madvise(p, size, MADV_DONTNEED);
+                        memory_purge(p, size);
                     }
                 }
 #endif
diff --git a/memory.c b/memory.c
index 7c5abb3..523e482 100644
--- a/memory.c
+++ b/memory.c
@@ -92,6 +92,14 @@ int memory_remap_fixed(void *old, size_t old_size, void *new, size_t new_size) {
 }
 #endif
 
+int memory_purge(void *ptr, size_t size) {
+    int ret = madvise(ptr, size, MADV_DONTNEED);
+    if (unlikely(ret) && errno != ENOMEM) {
+        fatal_error("non-ENOMEM MADV_DONTNEED madvise failure");
+    }
+    return ret;
+}
+
 void memory_set_name(UNUSED void *ptr, UNUSED size_t size, UNUSED const char *name) {
 #ifdef LABEL_MEMORY
     prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, name);
diff --git a/memory.h b/memory.h
index fe51546..bd28f1c 100644
--- a/memory.h
+++ b/memory.h
@@ -19,6 +19,7 @@ int memory_protect_rw_metadata(void *ptr, size_t size);
 int memory_remap(void *old, size_t old_size, size_t new_size);
 int memory_remap_fixed(void *old, size_t old_size, void *new, size_t new_size);
 #endif
+int memory_purge(void *ptr, size_t size);
 void memory_set_name(void *ptr, size_t size, const char *name);
 
 #endif