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93e72b3c61
ll_rw_block() function has been deprecated in favor of BIO which appears to come with large performance improvements. This patch decreases boot time by close to 40% when using squashfs for the root file-system. This is observed at least in the context of starting an Android VM on Chrome OS using crosvm. The patch was tested on 4.19 as well as master. This patch is largely based on Adrien Schildknecht's patch that was originally sent as https://lkml.org/lkml/2017/9/22/814 though with some significant changes and simplifications while also taking Phillip Lougher's feedback into account, around preserving support for FILE_CACHE in particular. [akpm@linux-foundation.org: fix build error reported by Randy] Link: http://lkml.kernel.org/r/319997c2-5fc8-f889-2ea3-d913308a7c1f@infradead.org Signed-off-by: Philippe Liard <pliard@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Adrien Schildknecht <adrien+dev@schischi.me> Cc: Phillip Lougher <phillip@squashfs.org.uk> Cc: Guenter Roeck <groeck@chromium.org> Cc: Daniel Rosenberg <drosen@google.com> Link: https://chromium.googlesource.com/chromiumos/platform/crosvm Link: http://lkml.kernel.org/r/20191106074238.186023-1-pliard@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2013
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* Phillip Lougher <phillip@squashfs.org.uk>
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*/
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/percpu.h>
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#include <linux/buffer_head.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 using percpu
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* variables, one thread per cpu core.
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*/
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struct squashfs_stream {
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void *stream;
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};
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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 squashfs_stream __percpu *percpu;
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int err, cpu;
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percpu = alloc_percpu(struct squashfs_stream);
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if (percpu == NULL)
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return ERR_PTR(-ENOMEM);
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for_each_possible_cpu(cpu) {
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stream = per_cpu_ptr(percpu, cpu);
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stream->stream = msblk->decompressor->init(msblk, comp_opts);
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if (IS_ERR(stream->stream)) {
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err = PTR_ERR(stream->stream);
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goto out;
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}
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}
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kfree(comp_opts);
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return (__force void *) percpu;
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out:
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for_each_possible_cpu(cpu) {
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stream = per_cpu_ptr(percpu, cpu);
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if (!IS_ERR_OR_NULL(stream->stream))
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msblk->decompressor->free(stream->stream);
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}
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free_percpu(percpu);
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return ERR_PTR(err);
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}
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void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
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{
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struct squashfs_stream __percpu *percpu =
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(struct squashfs_stream __percpu *) msblk->stream;
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struct squashfs_stream *stream;
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int cpu;
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if (msblk->stream) {
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for_each_possible_cpu(cpu) {
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stream = per_cpu_ptr(percpu, cpu);
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msblk->decompressor->free(stream->stream);
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}
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free_percpu(percpu);
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}
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}
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int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
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int offset, int length, struct squashfs_page_actor *output)
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{
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struct squashfs_stream __percpu *percpu;
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struct squashfs_stream *stream;
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int res;
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percpu = (struct squashfs_stream __percpu *)msblk->stream;
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stream = get_cpu_ptr(percpu);
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res = msblk->decompressor->decompress(msblk, stream->stream, bio,
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offset, length, output);
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put_cpu_ptr(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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int squashfs_max_decompressors(void)
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{
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return num_possible_cpus();
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}
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