Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753958AbbLCUnU (ORCPT ); Thu, 3 Dec 2015 15:43:20 -0500 Received: from casper.infradead.org ([85.118.1.10]:39964 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753918AbbLCUnS (ORCPT ); Thu, 3 Dec 2015 15:43:18 -0500 Date: Thu, 3 Dec 2015 21:43:13 +0100 From: Peter Zijlstra To: Tejun Heo Cc: Ulrich Obergfell , Ingo Molnar , Andrew Morton , linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH] workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue Message-ID: <20151203204313.GX17308@twins.programming.kicks-ass.net> References: <20151203002810.GJ19878@mtj.duckdns.org> <20151203093350.GP17308@twins.programming.kicks-ass.net> <20151203100018.GO11639@twins.programming.kicks-ass.net> <20151203144811.GA27463@mtj.duckdns.org> <20151203150442.GR17308@twins.programming.kicks-ass.net> <20151203150604.GC27463@mtj.duckdns.org> <20151203192616.GJ27463@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151203192616.GJ27463@mtj.duckdns.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1561 Lines: 31 On Thu, Dec 03, 2015 at 02:26:16PM -0500, Tejun Heo wrote: > + WARN_ONCE(current->flags & PF_MEMALLOC, I'm not sure about using PF_MEMALLOC for detecting reclaim. There appear to be more sites setting this than reclaim. See: drivers/block/nbd.c: current->flags |= PF_MEMALLOC; drivers/mmc/card/queue.c: current->flags |= PF_MEMALLOC; drivers/mtd/nand/nandsim.c: current->flags |= PF_MEMALLOC; drivers/scsi/iscsi_tcp.c: current->flags |= PF_MEMALLOC; drivers/staging/lustre/include/linux/libcfs/linux/linux-mem.h:#define memory_pressure_set() do { current->flags |= PF_MEMALLOC; } while (0) fs/cifs/connect.c: current->flags |= PF_MEMALLOC; fs/xfs/libxfs/xfs_btree.c: new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD; fs/xfs/xfs_trans_ail.c: current->flags |= PF_MEMALLOC; include/linux/sched.h: current->flags |= PF_MEMALLOC_NOIO; mm/page_alloc.c: current->flags |= PF_MEMALLOC; mm/page_alloc.c: current->flags |= PF_MEMALLOC; mm/vmscan.c: tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD; mm/vmscan.c: p->flags |= PF_MEMALLOC; mm/vmscan.c: p->flags |= PF_MEMALLOC | PF_SWAPWRITE; net/core/dev.c: current->flags |= PF_MEMALLOC; net/core/sock.c: current->flags |= PF_MEMALLOC; The actual reclaim sites in page_alloc and vmscan set current->reclaim_state. So testing against that might be more accurate. -- 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/