From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752503AbeDQOGD (ORCPT ); Tue, 17 Apr 2018 10:06:03 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:33061 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751345AbeDQOGB (ORCPT ); Tue, 17 Apr 2018 10:06:01 -0400 X-Google-Smtp-Source: AIpwx49Am1e1bdcrh6GXATf/ZRRRX8SEhJt5Kbw+MsbbhGW1t0Y8hM9lhoKIJ1RXE034CtL3+83JCQ== Date: Tue, 17 Apr 2018 16:00:32 +0200 From: Vitaly Wool To: Guenter Roeck Cc: LKML , Andrew Morton , mawilcox@microsoft.com, asavery@chromium.org, gwendal@chromium.org Subject: Re: Crashes/hung tasks with z3pool under memory pressure Message-ID: <20180417160032.46915216@seldlx21914.corpusers.net> X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guenter, > [ ... ] > > Ugh. Could you please keep that patch and apply this on top: > > > > diff --git a/mm/z3fold.c b/mm/z3fold.c > > index c0bca6153b95..e8a80d044d9e 100644 > > --- a/mm/z3fold.c > > +++ b/mm/z3fold.c > > @@ -840,6 +840,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) > > kref_get(&zhdr->refcount); > > list_del_init(&zhdr->buddy); > > zhdr->cpu = -1; > > + break; > > } > > list_del_init(&page->lru); > > > Much better, in a way. The system now takes much longer to crash, > and the crash reason is a bit different. The log is too long to attach, > so I copied it to [1]. > > crashdump.0002 Latest log > 000[12]-Fix-attempt-[12].patch Patches applied on top of v4.17.0-rc1. thanks for the update. Let's start from a clean sheet. I believe this patch has to be applied anyway so could you please check if it solves the problem. diff --git a/mm/z3fold.c b/mm/z3fold.c index c0bca6153b95..059fb3d5ca86 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -144,7 +144,8 @@ enum z3fold_page_flags { PAGE_HEADLESS = 0, MIDDLE_CHUNK_MAPPED, NEEDS_COMPACTING, - PAGE_STALE + PAGE_STALE, + UNDER_RECLAIM }; /***************** @@ -173,6 +174,7 @@ static struct z3fold_header *init_z3fold_page(struct page *page, clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); clear_bit(NEEDS_COMPACTING, &page->private); clear_bit(PAGE_STALE, &page->private); + clear_bit(UNDER_RECLAIM, &page->private); spin_lock_init(&zhdr->page_lock); kref_init(&zhdr->refcount); @@ -756,6 +758,10 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) atomic64_dec(&pool->pages_nr); return; } + if (test_bit(UNDER_RECLAIM, &page->private)) { + z3fold_page_unlock(zhdr); + return; + } if (test_and_set_bit(NEEDS_COMPACTING, &page->private)) { z3fold_page_unlock(zhdr); return; @@ -840,6 +846,8 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) kref_get(&zhdr->refcount); list_del_init(&zhdr->buddy); zhdr->cpu = -1; + set_bit(UNDER_RECLAIM, &page->private); + break; } list_del_init(&page->lru); @@ -888,6 +896,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) } next: spin_lock(&pool->lock); + clear_bit(UNDER_RECLAIM, &page->private); if (test_bit(PAGE_HEADLESS, &page->private)) { if (ret == 0) { spin_unlock(&pool->lock);