| Message ID | 546EB5A2.5050604@huawei.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Nov 21, 2014 at 11:46:42AM +0800, leizhen wrote: > During the development phase, we usually enlarge initrd-end to reserve more > memory than the initfs zip exactly occupied. Then we can easily add or delete > files in zip package, without generate fdt again and again. But unfortunately, > if too many zeros followed initfs zip, it will take a long time to break the > loop. > > while (!message && len) { > ... ... > if (!*buf) { > buf++; > ... ... > continue; > } > > So, use the boot option "initramfs_packnum" to specify how many zip packages > in each initrd area. When the specified number of packages decompressed in one > area, immediately terminate the loop. Have no impact on current use by default. This seems like the wrong approach to me. Rather than changing Linux to ignore excess data in the initramfs, could you change your bootloader to pass the true length of the initramfs to Linux? Even if you reserve extra space, if you know how much data you've actually included, you could have your bootloader pass that information to Linux. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 2014/11/21 12:02, Josh Triplett wrote: > On Fri, Nov 21, 2014 at 11:46:42AM +0800, leizhen wrote: >> During the development phase, we usually enlarge initrd-end to reserve more >> memory than the initfs zip exactly occupied. Then we can easily add or delete >> files in zip package, without generate fdt again and again. But unfortunately, >> if too many zeros followed initfs zip, it will take a long time to break the >> loop. >> >> while (!message && len) { >> ... ... >> if (!*buf) { >> buf++; >> ... ... >> continue; >> } >> >> So, use the boot option "initramfs_packnum" to specify how many zip packages >> in each initrd area. When the specified number of packages decompressed in one >> area, immediately terminate the loop. Have no impact on current use by default. > > This seems like the wrong approach to me. Rather than changing Linux to > ignore excess data in the initramfs, could you change your bootloader to > pass the true length of the initramfs to Linux? Even if you reserve > extra space, if you know how much data you've actually included, you > could have your bootloader pass that information to Linux. Yes, at release time, I will do it. But during development phase, men are lazy. Please consider the following scenario: We have test file1 and file2, they are all too big. We base upon file1 generated fs1.cpio.gz, and base upon file2 generated fs2.cpio.gz. We don't put file1 and file2 into one fs package, because the uploading is very slow on simulator or emulator. Now, we should keep fdt1 and fdt2 relate to two fs packages. If there are many test files, we should keep more fdts, it's not convenient. But with this patch, we only need keep one fdt, and get the result the same to pass the true length. > > - Josh Triplett > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/init/initramfs.c b/init/initramfs.c index ad1bd77..356764f 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -446,12 +446,24 @@ static unsigned long my_inptr; /* index of next byte to be processed in inbuf */ #include <linux/decompress/generic.h> +/* zero and negative means packages number is unlimited */ +static int initramfs_packnum __initdata; + +static __init int setup_initramfs_packnum(char *str) +{ + get_option(&str, &initramfs_packnum); + + return 0; +} +early_param("initramfs_packnum", setup_initramfs_packnum); + static char * __init unpack_to_rootfs(char *buf, unsigned long len) { long written; decompress_fn decompress; const char *compress_name; static __initdata char msg_buf[64]; + int packnum = initramfs_packnum; header_buf = kmalloc(110, GFP_KERNEL); symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); @@ -500,6 +512,9 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len) this_header = saved_offset + my_inptr; buf += my_inptr; len -= my_inptr; + + if (!(--packnum)) + break; } dir_utime(); kfree(name_buf);