The patch titled
Subject: squashfs: allows users to configure the number of decompression threads
has been added to the -mm mm-nonmm-unstable branch. Its filename is
squashfs-allows-users-to-configure-the-number-of-decompression-threads.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-allows-users-to-configure-the-number-of-decompression-threads.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Subject: squashfs: allows users to configure the number of decompression threads
Date: Wed, 19 Oct 2022 11:09:30 +0800
The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs. Therefore, the mount
parameter needs to be added to allow users to configure the number of
threads as required. The upper limit is num_online_cpus() * 2.
Link: https://lkml.kernel.org/r/20221019030930.130456-3-nixiaoming@xxxxxxxxxx
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Reviewed-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Cc: Jianguo Chen <chenjianguo3@xxxxxxxxxx>
Cc: Jubin Zhong <zhongjubin@xxxxxxxxxx>
Cc: Zhang Yi <yi.zhang@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/fs/squashfs/decompressor_multi.c~squashfs-allows-users-to-configure-the-number-of-decompression-threads
+++ a/fs/squashfs/decompressor_multi.c
@@ -144,7 +144,7 @@ static struct decomp_stream *get_decomp_
* If there is no available decomp and already full,
* let's wait for releasing decomp from other users.
*/
- if (stream->avail_decomp >= MAX_DECOMPRESSOR)
+ if (stream->avail_decomp >= msblk->max_thread_num)
goto wait;
/* Let's allocate new decomp */
@@ -160,7 +160,7 @@ static struct decomp_stream *get_decomp_
}
stream->avail_decomp++;
- WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR);
+ WARN_ON(stream->avail_decomp > msblk->max_thread_num);
mutex_unlock(&stream->mutex);
break;
--- a/fs/squashfs/Kconfig~squashfs-allows-users-to-configure-the-number-of-decompression-threads
+++ a/fs/squashfs/Kconfig
@@ -73,11 +73,10 @@ config SQUASHFS_CHOICE_DECOMP_BY_MOUNT
select SQUASHFS_DECOMP_SINGLE
select SQUASHFS_DECOMP_MULTI
select SQUASHFS_DECOMP_MULTI_PERCPU
+ select SQUASHFS_MOUNT_DECOMP_THREADS
help
Compile all parallel decompression modes and specify the
decompression mode by setting "threads=" during mount.
- threads=<single|multi|percpu>
-
default Decompressor parallelisation is SQUASHFS_DECOMP_SINGLE
choice
@@ -127,6 +126,19 @@ config SQUASHFS_COMPILE_DECOMP_MULTI_PER
decompression is load-balanced across the cores.
endchoice
+config SQUASHFS_MOUNT_DECOMP_THREADS
+ bool "Add the mount parameter 'threads=' for squashfs"
+ depends on SQUASHFS
+ depends on SQUASHFS_DECOMP_MULTI
+ default n
+ help
+ Use threads= to set the decompression parallel mode and the number of threads.
+ If SQUASHFS_CHOICE_DECOMP_BY_MOUNT=y
+ threads=<single|multi|percpu|1|2|3|...>
+ else
+ threads=<2|3|...>
+ The upper limit is num_online_cpus() * 2.
+
config SQUASHFS_XATTR
bool "Squashfs XATTR support"
depends on SQUASHFS
--- a/fs/squashfs/squashfs_fs_sb.h~squashfs-allows-users-to-configure-the-number-of-decompression-threads
+++ a/fs/squashfs/squashfs_fs_sb.h
@@ -67,5 +67,6 @@ struct squashfs_sb_info {
unsigned int ids;
bool panic_on_errors;
const struct squashfs_decompressor_thread_ops *thread_ops;
+ int max_thread_num;
};
#endif
--- a/fs/squashfs/super.c~squashfs-allows-users-to-configure-the-number-of-decompression-threads
+++ a/fs/squashfs/super.c
@@ -53,6 +53,7 @@ enum squashfs_param {
struct squashfs_mount_opts {
enum Opt_errors errors;
const struct squashfs_decompressor_thread_ops *thread_ops;
+ int thread_num;
};
static const struct constant_table squashfs_param_errors[] = {
@@ -67,7 +68,8 @@ static const struct fs_parameter_spec sq
{}
};
-static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)
+
+static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts)
{
#ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT
if (strcmp(str, "single") == 0) {
@@ -86,6 +88,42 @@ static int squashfs_parse_param_threads(
return -EINVAL;
}
+static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts)
+{
+#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
+ int ret;
+ unsigned long num;
+
+ ret = kstrtoul(str, 0, &num);
+ if (ret != 0)
+ return -EINVAL;
+ if (num > 1) {
+ opts->thread_ops = &squashfs_decompressor_multi;
+ if (num > opts->thread_ops->max_decompressors())
+ return -EINVAL;
+ opts->thread_num = (int)num;
+ return 0;
+ }
+#ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
+ if (num == 1) {
+ opts->thread_ops = &squashfs_decompressor_single;
+ opts->thread_num = 1;
+ return 0;
+ }
+#endif
+#endif /* !CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS */
+ return -EINVAL;
+}
+
+static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts)
+{
+ int ret = squashfs_parse_param_threads_str(str, opts);
+
+ if (ret == 0)
+ return ret;
+ return squashfs_parse_param_threads_num(str, opts);
+}
+
static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct squashfs_mount_opts *opts = fc->fs_private;
@@ -194,6 +232,11 @@ static int squashfs_fill_super(struct su
goto failed_mount;
}
msblk->thread_ops = opts->thread_ops;
+ if (opts->thread_num == 0) {
+ msblk->max_thread_num = msblk->thread_ops->max_decompressors();
+ } else {
+ msblk->max_thread_num = opts->thread_num;
+ }
/* Check the MAJOR & MINOR versions and lookup compression type */
msblk->decompressor = supported_squashfs_filesystem(
@@ -279,7 +322,7 @@ static int squashfs_fill_super(struct su
/* Allocate read_page block */
msblk->read_page = squashfs_cache_init("data",
- msblk->thread_ops->max_decompressors(), msblk->block_size);
+ msblk->max_thread_num, msblk->block_size);
if (msblk->read_page == NULL) {
errorf(fc, "Failed to allocate read_page block");
goto failed_mount;
@@ -467,15 +510,14 @@ static int squashfs_show_options(struct
seq_puts(s, ",threads=single");
return 0;
}
- if (msblk->thread_ops == &squashfs_decompressor_multi) {
- seq_puts(s, ",threads=multi");
- return 0;
- }
if (msblk->thread_ops == &squashfs_decompressor_percpu) {
seq_puts(s, ",threads=percpu");
return 0;
}
#endif
+#ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS
+ seq_printf(s, ",threads=%d", msblk->max_thread_num);
+#endif
return 0;
}
@@ -496,6 +538,7 @@ static int squashfs_init_fs_context(stru
#else
#error "fail: unknown squashfs decompression thread mode?"
#endif
+ opts->thread_num = 0;
fc->fs_private = opts;
fc->ops = &squashfs_context_ops;
return 0;
_
Patches currently in -mm which might be from nixiaoming@xxxxxxxxxx are
squashfs-add-the-mount-parameter-theads=singlemultipercpu.patch
squashfs-allows-users-to-configure-the-number-of-decompression-threads.patch
