Hi, On 03.06.2022 16:55, Hsin-Yi Wang wrote: > On Fri, Jun 3, 2022 at 10:10 PM Marek Szyprowski > <m.szyprowski@xxxxxxxxxxx> wrote: >> On 03.06.2022 14:59, Matthew Wilcox wrote: >>> On Fri, Jun 03, 2022 at 02:54:21PM +0200, Marek Szyprowski wrote: >>>> On 01.06.2022 12:39, Hsin-Yi Wang wrote: >>>>> Implement readahead callback for squashfs. It will read datablocks >>>>> which cover pages in readahead request. For a few cases it will >>>>> not mark page as uptodate, including: >>>>> - file end is 0. >>>>> - zero filled blocks. >>>>> - current batch of pages isn't in the same datablock or not enough in a >>>>> datablock. >>>>> - decompressor error. >>>>> Otherwise pages will be marked as uptodate. The unhandled pages will be >>>>> updated by readpage later. >>>>> >>>>> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> >>>>> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> >>>>> Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> >>>>> Reported-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx> >>>>> Reported-by: Xiongwei Song <Xiongwei.Song@xxxxxxxxxxxxx> >>>>> --- >>>> This patch landed recently in linux-next as commit 95f7a26191de >>>> ("squashfs: implement readahead"). I've noticed that it causes serious >>>> issues on my test systems (various ARM 32bit and 64bit based boards). >>>> The easiest way to observe is udev timeout 'waiting for /dev to be fully >>>> populated' and prolonged booting time. I'm using squashfs for deploying >>>> kernel modules via initrd. Reverting aeefca9dfae7 & 95f7a26191deon on >>>> top of the next-20220603 fixes the issue. >>> How large are these files? Just a few kilobytes? >> Yes, they are small, most of them are smaller than 16KB, some about >> 128KB and a few about 256KB. I've sent a detailed list in private mail. >> > Hi Marek, > > Are there any obvious squashfs errors in dmesg? Did you enable > CONFIG_SQUASHFS_FILE_DIRECT or CONFIG_SQUASHFS_FILE_CACHE? Here are related config entries from my .config: CONFIG_SQUASHFS=y CONFIG_SQUASHFS_FILE_CACHE=y # CONFIG_SQUASHFS_FILE_DIRECT is not set CONFIG_SQUASHFS_DECOMP_SINGLE=y # CONFIG_SQUASHFS_DECOMP_MULTI is not set # CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU is not set # CONFIG_SQUASHFS_XATTR is not set CONFIG_SQUASHFS_ZLIB=y # CONFIG_SQUASHFS_LZ4 is not set CONFIG_SQUASHFS_LZO=y CONFIG_SQUASHFS_XZ=y # CONFIG_SQUASHFS_ZSTD is not set # CONFIG_SQUASHFS_4K_DEVBLK_SIZE is not set # CONFIG_SQUASHFS_EMBEDDED is not set CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE=3 (I've used standard ARM 32bit multi_v7_defconfig) Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland