On 2023/12/4 01:32, Juhyung Park wrote:
Hi Gao,
...
What is the difference between these two machines? just different CPU or
they have some other difference like different compliers?
I fully and exclusively control both devices, and the setup is almost the same.
Same Ubuntu version, kernel/compiler version.
But as I said, on my laptop, the issue happens on kernels that someone
else (Canonical) built, so I don't think it matters.
The only thing I could say is that the kernel side has optimized
inplace decompression compared to fuse so that it will reuse the
same buffer for decompression but with a safe margin (according to
the current lz4 decompression implementation). It shouldn't behave
different just due to different CPUs. Let me find more clues
later, also maybe we should introduce a way for users to turn off
this if needed.
Cool :)
I'm comfortable changing and building my own custom kernel for this
specific laptop. Feel free to ask me to try out some patches.
Thanks, I need to narrow down this issue:
- First, could you apply the following diff to test if it's still
reproducable?
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 021be5feb1bc..40a306628e1a 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -131,7 +131,7 @@ static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx,
if (rq->inplace_io) {
omargin = PAGE_ALIGN(ctx->oend) - ctx->oend;
- if (rq->partial_decoding || !may_inplace ||
+ if (1 || rq->partial_decoding || !may_inplace ||
omargin < LZ4_DECOMPRESS_INPLACE_MARGIN(rq->inputsize))
goto docopy;
- Could you share the full message about the output of `lscpu`?
Thanks,
Gao Xiang
