From: SeongJae Park <sj38.park@gmail.com>
To: SeongJae Park <sj38.park@gmail.com>
Cc: Greg KH <greg@kroah.com>,
akpm@linux-foundation.org, SeongJae Park <sjpark@amazon.de>,
Jonathan.Cameron@huawei.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, amit@kernel.org,
benh@kernel.crashing.org, brendanhiggins@google.com,
corbet@lwn.net, david@redhat.com, dwmw@amazon.com,
elver@google.com, fan.du@intel.com, foersleo@amazon.de,
gthelen@google.com, guoju.fgj@alibaba-inc.com, mgorman@suse.de,
minchan@kernel.org, mingo@redhat.com, namhyung@kernel.org,
peterz@infradead.org, riel@surriel.com, rientjes@google.com,
rostedt@goodmis.org, rppt@kernel.org, shakeelb@google.com,
shuah@kernel.org, snu@amazon.de, vbabka@suse.cz,
vdavydov.dev@gmail.com, zgf574564920@gmail.com,
linux-damon@amazon.com, linux-mm@kvack.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v26 07/13] mm/damon: Implement a debugfs-based user space interface
Date: Tue, 30 Mar 2021 10:20:06 +0000 [thread overview]
Message-ID: <20210330102006.34049-1-sjpark@amazon.de> (raw)
In-Reply-To: <20210330095950.33427-1-sjpark@amazon.de>
From: SeongJae Park <sjpark@amazon.de>
On Tue, 30 Mar 2021 09:59:50 +0000 SeongJae Park <sj38.park@gmail.com> wrote:
> From: SeongJae Park <sjpark@amazon.de>
>
> On Tue, 30 Mar 2021 11:22:45 +0200 Greg KH <greg@kroah.com> wrote:
>
> > On Tue, Mar 30, 2021 at 09:05:31AM +0000, sj38.park@gmail.com wrote:
> > > +static int __init __damon_dbgfs_init(void)
> > > +{
> > > + struct dentry *dbgfs_root;
> > > + const char * const file_names[] = {"monitor_on"};
> > > + const struct file_operations *fops[] = {&monitor_on_fops};
> > > + int i;
> > > +
> > > + dbgfs_root = debugfs_create_dir("damon", NULL);
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(file_names); i++)
> > > + debugfs_create_file(file_names[i], 0600, dbgfs_root, NULL,
> > > + fops[i]);
> > > + dbgfs_fill_ctx_dir(dbgfs_root, dbgfs_ctxs[0]);
> > > +
> > > + dbgfs_dirs = kmalloc_array(1, sizeof(dbgfs_root), GFP_KERNEL);
> >
> > No error checking for memory allocation failures?
>
> Oops, I will add the check in the next spin.
>
> >
> >
> > > + dbgfs_dirs[0] = dbgfs_root;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +/*
> > > + * Functions for the initialization
> > > + */
> > > +
> > > +static int __init damon_dbgfs_init(void)
> > > +{
> > > + int rc;
> > > +
> > > + dbgfs_ctxs = kmalloc(sizeof(*dbgfs_ctxs), GFP_KERNEL);
> >
> > No error checking?
>
> Will add in the next spin.
>
> >
> > > + dbgfs_ctxs[0] = dbgfs_new_ctx();
> > > + if (!dbgfs_ctxs[0])
> > > + return -ENOMEM;
And, I found that I'm not printing the error for this failure. I guess this
might made you to to think below error message should printed inside the
callee.
I will add 'pr_err()' here and above unchecked failure case, in the next
version.
BTW, I forgot saying thank you for your review. Appreciate!
Thanks,
SeongJae Park
> > > + dbgfs_nr_ctxs = 1;
> > > +
> > > + rc = __damon_dbgfs_init();
> > > + if (rc)
> > > + pr_err("%s: dbgfs init failed\n", __func__);
> >
> > Shouldn't the error be printed out in the function that failed, not in
> > this one?
>
> I thought some other functions (in future) might want to use
> '__damon_dbgfs_init()' but siletnly handles it's failure. Therefore I made the
> function fails silently but returns the error code explicitly. Am I missing
> somthing?
>
>
> Thanks,
> SeongJae Park
>
> >
> > thanks,
> >
> > greg k-h
>
next prev parent reply other threads:[~2021-03-30 10:20 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 9:05 [PATCH v26 00/13] Introduce Data Access MONitor (DAMON) sj38.park
2021-03-30 9:05 ` [PATCH v26 01/13] mm: " sj38.park
2021-03-30 9:05 ` [PATCH v26 02/13] mm/damon/core: Implement region-based sampling sj38.park
2021-03-30 9:05 ` [PATCH v26 03/13] mm/damon: Adaptively adjust regions sj38.park
2021-03-30 9:05 ` [PATCH v26 04/13] mm/idle_page_tracking: Make PG_idle reusable sj38.park
2021-03-30 9:05 ` [PATCH v26 05/13] mm/damon: Implement primitives for the virtual memory address spaces sj38.park
2021-03-30 9:05 ` [PATCH v26 06/13] mm/damon: Add a tracepoint sj38.park
2021-03-30 9:05 ` [PATCH v26 07/13] mm/damon: Implement a debugfs-based user space interface sj38.park
2021-03-30 9:22 ` Greg KH
2021-03-30 9:59 ` SeongJae Park
2021-03-30 10:20 ` SeongJae Park [this message]
2021-03-30 9:05 ` [PATCH v26 08/13] mm/damon/dbgfs: Export kdamond pid to the user space sj38.park
2021-03-30 9:05 ` [PATCH v26 09/13] mm/damon/dbgfs: Support multiple contexts sj38.park
2021-03-30 9:05 ` [PATCH v26 10/13] Documentation: Add documents for DAMON sj38.park
2021-03-30 9:05 ` [PATCH v26 11/13] mm/damon: Add kunit tests sj38.park
2021-03-30 9:05 ` [PATCH v26 12/13] mm/damon: Add user space selftests sj38.park
2021-03-30 9:05 ` [PATCH v26 13/13] MAINTAINERS: Update for DAMON sj38.park
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