From: David Hildenbrand <david@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Pankaj Gupta" <pankaj.gupta.linux@gmail.com>,
"Gavin Shan" <gshan@redhat.com>,
"Daniel P . Berrangé" <berrange@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Michal Prívozník" <mprivozn@redhat.com>,
"David Hildenbrand" <david@redhat.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
"Sebastien Boeuf" <sebastien.boeuf@intel.com>,
"Igor Mammedov" <imammedo@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Hui Zhu" <teawater@gmail.com>
Subject: [PATCH v2 1/8] util/oslib-posix: Let touch_all_pages() return an error
Date: Fri, 17 Dec 2021 14:46:04 +0100 [thread overview]
Message-ID: <20211217134611.31172-2-david@redhat.com> (raw)
In-Reply-To: <20211217134611.31172-1-david@redhat.com>
Let's prepare touch_all_pages() for returning differing errors. Return
an error from the thread and report the last processed error.
Translate SIGBUS to -EFAULT, as a SIGBUS can mean all different kind of
things (memory error, read error, out of memory). When allocating memory
fails via the current SIGBUS-based mechanism, we'll get:
os_mem_prealloc: preallocating memory failed: Bad address
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
util/oslib-posix.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index e8bdb02e1d..b146beef78 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -84,7 +84,6 @@ typedef struct MemsetThread MemsetThread;
static MemsetThread *memset_thread;
static int memset_num_threads;
-static bool memset_thread_failed;
static QemuMutex page_mutex;
static QemuCond page_cond;
@@ -452,6 +451,7 @@ static void *do_touch_pages(void *arg)
{
MemsetThread *memset_args = (MemsetThread *)arg;
sigset_t set, oldset;
+ int ret = 0;
/*
* On Linux, the page faults from the loop below can cause mmap_sem
@@ -470,7 +470,7 @@ static void *do_touch_pages(void *arg)
pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
if (sigsetjmp(memset_args->env, 1)) {
- memset_thread_failed = true;
+ ret = -EFAULT;
} else {
char *addr = memset_args->addr;
size_t numpages = memset_args->numpages;
@@ -494,7 +494,7 @@ static void *do_touch_pages(void *arg)
}
}
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
- return NULL;
+ return (void *)(uintptr_t)ret;
}
static inline int get_memset_num_threads(int smp_cpus)
@@ -509,13 +509,13 @@ static inline int get_memset_num_threads(int smp_cpus)
return ret;
}
-static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
- int smp_cpus)
+static int touch_all_pages(char *area, size_t hpagesize, size_t numpages,
+ int smp_cpus)
{
static gsize initialized = 0;
size_t numpages_per_thread, leftover;
+ int ret = 0, i = 0;
char *addr = area;
- int i = 0;
if (g_once_init_enter(&initialized)) {
qemu_mutex_init(&page_mutex);
@@ -523,7 +523,6 @@ static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
g_once_init_leave(&initialized, 1);
}
- memset_thread_failed = false;
threads_created_flag = false;
memset_num_threads = get_memset_num_threads(smp_cpus);
memset_thread = g_new0(MemsetThread, memset_num_threads);
@@ -545,12 +544,16 @@ static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
qemu_mutex_unlock(&page_mutex);
for (i = 0; i < memset_num_threads; i++) {
- qemu_thread_join(&memset_thread[i].pgthread);
+ int tmp = (uintptr_t)qemu_thread_join(&memset_thread[i].pgthread);
+
+ if (tmp) {
+ ret = tmp;
+ }
}
g_free(memset_thread);
memset_thread = NULL;
- return memset_thread_failed;
+ return ret;
}
void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus,
@@ -573,9 +576,10 @@ void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus,
}
/* touch pages simultaneously */
- if (touch_all_pages(area, hpagesize, numpages, smp_cpus)) {
- error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
- "pages available to allocate guest RAM");
+ ret = touch_all_pages(area, hpagesize, numpages, smp_cpus);
+ if (ret) {
+ error_setg_errno(errp, -ret,
+ "os_mem_prealloc: preallocating memory failed");
}
ret = sigaction(SIGBUS, &oldact, NULL);
--
2.31.1
next prev parent reply other threads:[~2021-12-17 13:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-17 13:46 [PATCH v2 0/8] virtio-mem: Support "prealloc=on" David Hildenbrand
2021-12-17 13:46 ` David Hildenbrand [this message]
2021-12-17 13:46 ` [PATCH v2 2/8] util/oslib-posix: Support MADV_POPULATE_WRITE for os_mem_prealloc() David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 3/8] util/oslib-posix: Introduce and use MemsetContext for touch_all_pages() David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 4/8] util/oslib-posix: Don't create too many threads with small memory or little pages David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 5/8] util/oslib-posix: Avoid creating a single thread with MADV_POPULATE_WRITE David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 6/8] util/oslib-posix: Support concurrent os_mem_prealloc() invocation David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 7/8] util/oslib-posix: Forward SIGBUS to MCE handler under Linux David Hildenbrand
2021-12-17 13:46 ` [PATCH v2 8/8] virtio-mem: Support "prealloc=on" option David Hildenbrand
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