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![Xiaoming Ni](/assets/img/avatar_default.png)
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@huawei.com Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk> Cc: Jianguo Chen <chenjianguo3@huawei.com> Cc: Jubin Zhong <zhongjubin@huawei.com> Cc: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
203 lines
4.8 KiB
C
203 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2013
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* Minchan Kim <minchan@kernel.org>
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*/
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/bio.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/cpumask.h>
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#include "squashfs_fs.h"
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#include "squashfs_fs_sb.h"
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#include "decompressor.h"
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#include "squashfs.h"
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/*
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* This file implements multi-threaded decompression in the
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* decompressor framework
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*/
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/*
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* The reason that multiply two is that a CPU can request new I/O
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* while it is waiting previous request.
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*/
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#define MAX_DECOMPRESSOR (num_online_cpus() * 2)
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static int squashfs_max_decompressors(void)
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{
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return MAX_DECOMPRESSOR;
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}
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struct squashfs_stream {
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void *comp_opts;
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struct list_head strm_list;
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struct mutex mutex;
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int avail_decomp;
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wait_queue_head_t wait;
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};
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struct decomp_stream {
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void *stream;
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struct list_head list;
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};
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static void put_decomp_stream(struct decomp_stream *decomp_strm,
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struct squashfs_stream *stream)
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{
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mutex_lock(&stream->mutex);
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list_add(&decomp_strm->list, &stream->strm_list);
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mutex_unlock(&stream->mutex);
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wake_up(&stream->wait);
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}
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static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
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void *comp_opts)
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{
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struct squashfs_stream *stream;
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struct decomp_stream *decomp_strm = NULL;
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int err = -ENOMEM;
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stream = kzalloc(sizeof(*stream), GFP_KERNEL);
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if (!stream)
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goto out;
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stream->comp_opts = comp_opts;
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mutex_init(&stream->mutex);
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INIT_LIST_HEAD(&stream->strm_list);
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init_waitqueue_head(&stream->wait);
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/*
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* We should have a decompressor at least as default
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* so if we fail to allocate new decompressor dynamically,
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* we could always fall back to default decompressor and
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* file system works.
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*/
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decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
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if (!decomp_strm)
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goto out;
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decomp_strm->stream = msblk->decompressor->init(msblk,
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stream->comp_opts);
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if (IS_ERR(decomp_strm->stream)) {
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err = PTR_ERR(decomp_strm->stream);
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goto out;
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}
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list_add(&decomp_strm->list, &stream->strm_list);
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stream->avail_decomp = 1;
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return stream;
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out:
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kfree(decomp_strm);
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kfree(stream);
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return ERR_PTR(err);
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}
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static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
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{
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struct squashfs_stream *stream = msblk->stream;
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if (stream) {
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struct decomp_stream *decomp_strm;
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while (!list_empty(&stream->strm_list)) {
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decomp_strm = list_entry(stream->strm_list.prev,
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struct decomp_stream, list);
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list_del(&decomp_strm->list);
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msblk->decompressor->free(decomp_strm->stream);
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kfree(decomp_strm);
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stream->avail_decomp--;
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}
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WARN_ON(stream->avail_decomp);
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kfree(stream->comp_opts);
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kfree(stream);
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}
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}
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static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk,
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struct squashfs_stream *stream)
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{
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struct decomp_stream *decomp_strm;
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while (1) {
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mutex_lock(&stream->mutex);
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/* There is available decomp_stream */
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if (!list_empty(&stream->strm_list)) {
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decomp_strm = list_entry(stream->strm_list.prev,
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struct decomp_stream, list);
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list_del(&decomp_strm->list);
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mutex_unlock(&stream->mutex);
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break;
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}
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/*
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* If there is no available decomp and already full,
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* let's wait for releasing decomp from other users.
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*/
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if (stream->avail_decomp >= msblk->max_thread_num)
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goto wait;
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/* Let's allocate new decomp */
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decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
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if (!decomp_strm)
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goto wait;
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decomp_strm->stream = msblk->decompressor->init(msblk,
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stream->comp_opts);
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if (IS_ERR(decomp_strm->stream)) {
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kfree(decomp_strm);
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goto wait;
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}
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stream->avail_decomp++;
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WARN_ON(stream->avail_decomp > msblk->max_thread_num);
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mutex_unlock(&stream->mutex);
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break;
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wait:
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/*
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* If system memory is tough, let's for other's
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* releasing instead of hurting VM because it could
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* make page cache thrashing.
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*/
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mutex_unlock(&stream->mutex);
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wait_event(stream->wait,
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!list_empty(&stream->strm_list));
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}
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return decomp_strm;
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}
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static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
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int offset, int length,
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struct squashfs_page_actor *output)
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{
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int res;
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struct squashfs_stream *stream = msblk->stream;
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struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream);
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res = msblk->decompressor->decompress(msblk, decomp_stream->stream,
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bio, offset, length, output);
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put_decomp_stream(decomp_stream, stream);
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if (res < 0)
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ERROR("%s decompression failed, data probably corrupt\n",
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msblk->decompressor->name);
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return res;
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}
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const struct squashfs_decompressor_thread_ops squashfs_decompressor_multi = {
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.create = squashfs_decompressor_create,
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.destroy = squashfs_decompressor_destroy,
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.decompress = squashfs_decompress,
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.max_decompressors = squashfs_max_decompressors,
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};
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