Adding debian version 4.19.249-2.debian/4.19.249-2debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/debian/patches-rt/0173-squashfs-make-use-of-local-lock-in-multi_cpu-decompr.patch b/debian/patches-rt/0173-squashfs-make-use-of-local-lock-in-multi_cpu-decompr.patch
new file mode 100644
index 000000000..e885134f9
--- /dev/null
+++ b/debian/patches-rt/0173-squashfs-make-use-of-local-lock-in-multi_cpu-decompr.patch
@@ -0,0 +1,72 @@
+From 98873b747e4321516bb428c214fde307593e19f8 Mon Sep 17 00:00:00 2001
+From: Julia Cartwright <julia@ni.com>
+Date: Mon, 7 May 2018 08:58:57 -0500
+Subject: [PATCH 173/347] squashfs: make use of local lock in multi_cpu
+ decompressor
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+Currently, the squashfs multi_cpu decompressor makes use of
+get_cpu_ptr()/put_cpu_ptr(), which unconditionally disable preemption
+during decompression.
+
+Because the workload is distributed across CPUs, all CPUs can observe a
+very high wakeup latency, which has been seen to be as much as 8000us.
+
+Convert this decompressor to make use of a local lock, which will allow
+execution of the decompressor with preemption-enabled, but also ensure
+concurrent accesses to the percpu compressor data on the local CPU will
+be serialized.
+
+Cc: stable-rt@vger.kernel.org
+Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
+Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
+Signed-off-by: Julia Cartwright <julia@ni.com>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ fs/squashfs/decompressor_multi_percpu.c | 16 ++++++++++++----
+ 1 file changed, 12 insertions(+), 4 deletions(-)
+
+diff --git a/fs/squashfs/decompressor_multi_percpu.c b/fs/squashfs/decompressor_multi_percpu.c
+index 23a9c28ad8ea..6a73c4fa88e7 100644
+--- a/fs/squashfs/decompressor_multi_percpu.c
++++ b/fs/squashfs/decompressor_multi_percpu.c
+@@ -10,6 +10,7 @@
+ #include <linux/slab.h>
+ #include <linux/percpu.h>
+ #include <linux/buffer_head.h>
++#include <linux/locallock.h>
+ 
+ #include "squashfs_fs.h"
+ #include "squashfs_fs_sb.h"
+@@ -25,6 +26,8 @@ struct squashfs_stream {
+ 	void		*stream;
+ };
+ 
++static DEFINE_LOCAL_IRQ_LOCK(stream_lock);
++
+ void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
+ 						void *comp_opts)
+ {
+@@ -79,10 +82,15 @@ int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
+ {
+ 	struct squashfs_stream __percpu *percpu =
+ 			(struct squashfs_stream __percpu *) msblk->stream;
+-	struct squashfs_stream *stream = get_cpu_ptr(percpu);
+-	int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
+-		offset, length, output);
+-	put_cpu_ptr(stream);
++	struct squashfs_stream *stream;
++	int res;
++
++	stream = get_locked_ptr(stream_lock, percpu);
++
++	res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
++			offset, length, output);
++
++	put_locked_ptr(stream_lock, stream);
+ 
+ 	if (res < 0)
+ 		ERROR("%s decompression failed, data probably corrupt\n",
+-- 
+2.36.1
+