On Wed 03-10-18 16:18:37, Ashish Mhetre wrote: > > How? No allocation request from the interrupt context can use a > > sleepable allocation context and that means that no reclaim is allowed > > from the IRQ context. > Kernel Oops happened when ZRAM was used as swap with zsmalloc as alloctor > under memory pressure condition. > This is probably because of kmalloc() from IRQ as pointed out by Sergey. Yes most likely and that should be fixed. > > Could you provide the Oops message? > BUG_ON() got triggered at https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/mm/zsmalloc.c?h=next-20181002#n1324 with Oops message: > [ 264.082531] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM > [ 264.088350] Modules linked in: > [ 264.091406] CPU: 0 PID: 3805 Comm: kworker/0:4 Tainted: G W > 3.10.33-g990282b #1 > [ 264.099572] Workqueue: events netstat_work_func > [ 264.104097] task: e7b12040 ti: dc7d4000 task.ti: dc7d4000 > [ 264.109485] PC is at zs_map_object+0x180/0x18c > [ 264.113918] LR is at zram_bvec_rw.isra.15+0x304/0x88c > [ 264.118956] pc : [<c01581e8>] lr : [<c0456618>] psr: 200f0013 > [ 264.118956] sp : dc7d5460 ip : fff00814 fp : 00000002 > [ 264.130407] r10: ea8ec000 r9 : ebc93340 r8 : 00000000 > [ 264.135618] r7 : c191502c r6 : dc7d4020 r5 : d25f5684 r4 : ec3158c0 > [ 264.142128] r3 : 00000200 r2 : 00000002 r1 : c191502c r0 : ea8ec000 This doesn't show the backtrace part which contains the allocation AFAICS. -- Michal Hocko SUSE Labs
