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98b830d260
Make nandsim use GFP_NOFS when allocating memory, because it might be used by a file-system (e.g. UBIFS2) which means, if we are short of memory, we may deadlock. Indee, UBIFS is holding a lock, writes to the media, reaches this place in NANDsim, kmalloc does not find the requested amount of RAM, calls memory shrinker, which decides to writeback inodes, calls FS, and it deadlocks on the lock which is already being held. Below is the UBIFS backtrace which demonstrates that: [<c03717dc>] __mutex_lock_slowpath+0xc8/0x2e6 [<c0371a16>] mutex_lock+0x1c/0x1f [<f8b9d076>] reserve_space+0x3d/0xa9 [ubifs] [<f8b9d1bd>] make_one_reservation+0x2b/0x86 [ubifs] [<f8b9d3fc>] ubifs_jrn_write_block+0xda/0x12f [ubifs] [<f8b9ff3a>] ubifs_writepage+0x11d/0x1ec [ubifs] [<c015d6ab>] shrink_inactive_list+0x7fa/0x969 [<c015d8c8>] shrink_zone+0xae/0x10c [<c015e3b4>] try_to_free_pages+0x159/0x251 [<c015980a>] __alloc_pages+0x125/0x2f0 [<c016ff6a>] cache_alloc_refill+0x380/0x6ba [<c01703f3>] __kmalloc+0x14f/0x157 [<f885722a>] do_state_action+0xab7/0xc74 [nandsim] [<f885760c>] switch_state+0x225/0x402 [nandsim] [<f8857e7e>] ns_hwcontrol+0x3e2/0x620 [nandsim] [<f8862f53>] nand_command+0x2e/0x1a5 [nand] [<f8861ad8>] nand_write_page+0x4a/0x9a [nand] [<f88617b4>] nand_do_write_ops+0x1cf/0x343 [nand] [<f8861a70>] nand_write+0x88/0xa6 [nand] [<f8850b0e>] part_write+0x72/0x8b [mtd] [<f88e19c5>] ubi_io_write+0x189/0x29c [ubi] [<f88dfb98>] ubi_eba_write_leb+0xb6/0x699 [ubi] [<f88def93>] ubi_leb_write+0xe4/0xe9 [ubi] [<f8ba3b82>] ubifs_wbuf_write_nolock+0x333/0x4c9 [ubifs] [<f8b9d28c>] write_node+0x74/0x8e [ubifs] [<f8b9d422>] ubifs_jrn_write_block+0x100/0x12f [ubifs] [<f8b9ff3a>] ubifs_writepage+0x11d/0x1ec [ubifs] [<c0159e5b>] __writepage+0xb/0x26 [<c015a318>] write_cache_pages+0x203/0x2d9 [<c015a411>] generic_writepages+0x23/0x2d [<c015a452>] do_writepages+0x37/0x39 [<c018e24a>] __writeback_single_inode+0x96/0x399 [<c018e903>] sync_sb_inodes+0x1a3/0x274 [<c018ebf3>] writeback_inodes+0xa6/0xd8 [<c015a9dd>] background_writeout+0x86/0x9e [<c015ae9c>] pdflush+0xfb/0x1b6 [<c01387d7>] kthread+0x37/0x59 [<c0104dc3>] kernel_thread_helper+0x7/0x14 The deadlock is funny because it starts in pdflush/writeback, and comes back to writeback, then deadlocks. It seems we should look carefully for other places in UBI and MTD and use GFP_NOFS instead of GFP_KERNEL. Caught-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org> |
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| .. | ||
| alauda.c | ||
| ams-delta.c | ||
| at91_nand.c | ||
| au1550nd.c | ||
| autcpu12.c | ||
| cafe_nand.c | ||
| cmx270_nand.c | ||
| cs553x_nand.c | ||
| diskonchip.c | ||
| edb7312.c | ||
| excite_nandflash.c | ||
| h1910.c | ||
| Kconfig | ||
| Makefile | ||
| nand_base.c | ||
| nand_bbt.c | ||
| nand_ecc.c | ||
| nand_ids.c | ||
| nandsim.c | ||
| ndfc.c | ||
| plat_nand.c | ||
| ppchameleonevb.c | ||
| rtc_from4.c | ||
| s3c2410.c | ||
| sharpsl.c | ||
| spia.c | ||
| toto.c | ||
| ts7250.c | ||