Hi, I am new to bcache and I am looking for a bcache patch for linux kernel version 3.0. Initially, form a 3.7 kernel, I prepared a patch and applied to 3.0 kernel. But in this case, I encounter "null pointer dereference". I am trying to use ramdisk as cache device and mmc partiton as backing device. Unable to handle kernel NULL pointer dereference at virtual address 00000000 kernel BUG at fs/bio.c:424! Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 817 [#1] PREEMPT Modules linked in: CPU: 0 Not tainted (3.0.8-00054-gece392b-dirty #5) PC is at __bug+0x1c/0x24 LR is at __bug+0x18/0x24 pc : [<c003c584>] lr : [<c003c580>] psr: 60000193 sp : f0bf7d88 ip : f0bf7cc0 fp : 00000000 r10: f02f3000 r9 : e2b70400 r8 : e2b70400 r7 : 00000000 r6 : 00000800 r5 : 00000000 r4 : 00000000 r3 : 00000000 r2 : 00000001 r1 : 00000002 r0 : 00000022 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4da00019 DAC: 00000015 PC: 0xc003c504: So, I am trying to debug this issue. My guess is back porting bcache from 3.7 kernel may not be the right way. I am looking for help in getting a bcache 3.0 patch. If anybody can give me some pointers in order to get that patch, that will be really helpful to me. Regards Ashim -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html