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[209.85.220.65]) by mx.google.com with SMTPS id m23sor45648749otf.164.2019.08.06.14.05.37 for (Google Transport Security); Tue, 06 Aug 2019 14:05:37 -0700 (PDT) Received-SPF: pass (google.com: domain of dan.j.williams@intel.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@intel-com.20150623.gappssmtp.com header.s=20150623 header.b=z2yxKPxy; spf=pass (google.com: domain of dan.j.williams@intel.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=dan.j.williams@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bL9WIDO7sBDPuzb3CXk+Z4+KurUQJsfGVwyfuIglMnE=; b=z2yxKPxyTcUc/O0JPDhYlubCTmWn88V/XHMgPAW10JVY9PDY328HIFjdo5D72jUH9f NgLzeLRf01N3eu0r1mdcfI7/BvjmTgkY/TwdpldwvbZ6CYEkwmp0eYXtVjobhRaRQuLv UKVBPLyKcHIhmZ3R5exIUzoaoQVCcIZsFwVAzTGEHH8mOBIpEeJV0N4FZvasdWo3/BMo KGuoLOtTZHjpAh9PykT0gDKxN/TsFkitTz6RF0I1c9hGrl8ZOrgqZWNkXh78fIJeqajS J0PWgZNpFBbIOgjBn3Sa58UezqTODB4r3nJN4DcwPF/L6QTs9YSzBz3/MuR4za3eFBwA +vLA== X-Google-Smtp-Source: APXvYqz/Ak9jnetJg9GXee4VtqrfI/7ybe9DtdbHdF+C7k/OSWwPkzRw1cnJyGFIKt8iguhq8EC0LfgFQg7v9HFSu0g= X-Received: by 2002:a9d:470d:: with SMTP id a13mr4639053otf.126.1565125537390; Tue, 06 Aug 2019 14:05:37 -0700 (PDT) MIME-Version: 1.0 References: <1565112345-28754-1-git-send-email-jane.chu@oracle.com> <1565112345-28754-2-git-send-email-jane.chu@oracle.com> In-Reply-To: <1565112345-28754-2-git-send-email-jane.chu@oracle.com> From: Dan Williams Date: Tue, 6 Aug 2019 14:05:25 -0700 Message-ID: Subject: Re: [PATCH v4 1/2] mm/memory-failure.c clean up around tk pre-allocation To: Jane Chu Cc: Naoya Horiguchi , Linux MM , Linux Kernel Mailing List , linux-nvdimm Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Jane, looks good. Checkpatch prompts me to point out a couple more fixups: This patch is titled: "mm/memory-failure.c clean up..." ...to match the second patch it should be: "mm/memory-failure: clean up..." On Tue, Aug 6, 2019 at 10:26 AM Jane Chu wrote: > > add_to_kill() expects the first 'tk' to be pre-allocated, it makes > subsequent allocations on need basis, this makes the code a bit > difficult to read. Move all the allocation internal to add_to_kill() > and drop the **tk argument. > > Signed-off-by: Jane Chu > --- > mm/memory-failure.c | 40 +++++++++++++--------------------------- > 1 file changed, 13 insertions(+), 27 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index d9cc660..51d5b20 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -304,25 +304,19 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, > /* > * Schedule a process for later kill. > * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. > - * TBD would GFP_NOIO be enough? > */ > static void add_to_kill(struct task_struct *tsk, struct page *p, > struct vm_area_struct *vma, > - struct list_head *to_kill, > - struct to_kill **tkc) > + struct list_head *to_kill) > { > struct to_kill *tk; > > - if (*tkc) { > - tk = *tkc; > - *tkc = NULL; > - } else { > - tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); > - if (!tk) { > - pr_err("Memory failure: Out of memory while machine check handling\n"); > - return; > - } > + tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); > + if (!tk) { > + pr_err("Memory failure: Out of memory while machine check handling\n"); > + return; > } checkpatch points out that this error message can be deleted. According to the commit that added this check (ebfdc40969f2 "checkpatch: attempt to find unnecessary 'out of memory' messages") the kernel already prints a message and a backtrace on these events, so seems like a decent additional cleanup to fold. With those fixups you can add: Reviewed-by: Dan Williams ...along with Naoya's ack. I would Cc: Andrew Morton on the v5 posting of these as he's the upstream path for changes to this file.