forked from pool/wayland
75 lines
2.2 KiB
Diff
75 lines
2.2 KiB
Diff
|
From b20428663afa1a6351eb943b5f2992a744c18797 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Olivier Fourdan <ofourdan@redhat.com>
|
||
|
|
Date: Mon, 10 Jan 2022 15:10:07 +0100
|
||
|
|
Subject: [PATCH] shm: Close file descriptors not needed
|
||
|
|
|
||
|
|
Commit 5a981ee8 implemented a fallback path for platforms which do not
|
||
|
|
support mremap() such as FreeBSD.
|
||
|
|
|
||
|
|
To do so, the file descriptor for the mmap() is not closed immediately
|
||
|
|
but instead kept as long as the pool exists.
|
||
|
|
|
||
|
|
That induces more file descriptors kept open for longer, which in turn
|
||
|
|
may cause problems as wl_shm may be using a lot of file descriptors,
|
||
|
|
especially with Xwayland which can create a lot of pixmaps on behalf of
|
||
|
|
its X11 clients.
|
||
|
|
|
||
|
|
For platforms where mremap() is available, keeping those file
|
||
|
|
descriptors opened is a bit of a waste and may cause exhaustion of file
|
||
|
|
descriptors sooner that before commit 5a981ee8.
|
||
|
|
|
||
|
|
Only keep the mmap() file descriptor open on platforms which do not
|
||
|
|
implement mremap() and close it immediately as before on others.
|
||
|
|
|
||
|
|
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
|
||
|
|
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1283
|
||
|
|
---
|
||
|
|
src/wayland-shm.c | 8 ++++++++
|
||
|
|
1 file changed, 8 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/src/wayland-shm.c b/src/wayland-shm.c
|
||
|
|
index 63ac0d7d..17ab77f4 100644
|
||
|
|
--- a/src/wayland-shm.c
|
||
|
|
+++ b/src/wayland-shm.c
|
||
|
|
@@ -65,10 +65,12 @@ struct wl_shm_pool {
|
||
|
|
char *data;
|
||
|
|
ssize_t size;
|
||
|
|
ssize_t new_size;
|
||
|
|
+#ifndef MREMAP_MAYMOVE
|
||
|
|
/* The following three fields are needed for mremap() emulation. */
|
||
|
|
int mmap_fd;
|
||
|
|
int mmap_flags;
|
||
|
|
int mmap_prot;
|
||
|
|
+#endif
|
||
|
|
bool sigbus_is_impossible;
|
||
|
|
};
|
||
|
|
|
||
|
|
@@ -153,7 +155,9 @@ shm_pool_unref(struct wl_shm_pool *pool, bool external)
|
||
|
|
return;
|
||
|
|
|
||
|
|
munmap(pool->data, pool->size);
|
||
|
|
+#ifndef MREMAP_MAYMOVE
|
||
|
|
close(pool->mmap_fd);
|
||
|
|
+#endif
|
||
|
|
free(pool);
|
||
|
|
}
|
||
|
|
|
||
|
|
@@ -344,10 +348,14 @@ shm_create_pool(struct wl_client *client, struct wl_resource *resource,
|
||
|
|
strerror(errno));
|
||
|
|
goto err_free;
|
||
|
|
}
|
||
|
|
+#ifndef MREMAP_MAYMOVE
|
||
|
|
/* We may need to keep the fd, prot and flags to emulate mremap(). */
|
||
|
|
pool->mmap_fd = fd;
|
||
|
|
pool->mmap_prot = prot;
|
||
|
|
pool->mmap_flags = flags;
|
||
|
|
+#else
|
||
|
|
+ close(fd);
|
||
|
|
+#endif
|
||
|
|
pool->resource =
|
||
|
|
wl_resource_create(client, &wl_shm_pool_interface, 1, id);
|
||
|
|
if (!pool->resource) {
|
||
|
|
--
|
||
|
|
GitLab
|
||
|
|
|