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From: Richard Henderson <richard.henderson@linaro.org>
To: Bin Meng <bmeng@tinylab.org>, qemu-devel@nongnu.org
Cc: Zhangjin Wu <falcon@tinylab.org>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Markus Armbruster <armbru@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH v2 3/6] util/async-teardown: Fall back to close fds one by one
Date: Mon, 19 Jun 2023 08:59:43 +0200	[thread overview]
Message-ID: <c1e1c570-828a-f943-adfe-7d0fc05a2389@linaro.org> (raw)
In-Reply-To: <20230616152737.23545-4-bmeng@tinylab.org>

On 6/16/23 17:27, Bin Meng wrote:
> When opening /proc/self/fd fails, current codes just return directly,
> but we can fall back to close fds one by one.
> 
> Signed-off-by: Bin Meng <bmeng@tinylab.org>
> ---
> 
> (no changes since v1)
> 
>   util/async-teardown.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/util/async-teardown.c b/util/async-teardown.c
> index 3ab19c8740..7e0177a8da 100644
> --- a/util/async-teardown.c
> +++ b/util/async-teardown.c
> @@ -48,7 +48,11 @@ static void close_all_open_fd(void)
>   
>       dir = opendir("/proc/self/fd");
>       if (!dir) {
> -        /* If /proc is not mounted, there is nothing that can be done. */
> +        /* If /proc is not mounted, close fds one by one. */
> +        int open_max = sysconf(_SC_OPEN_MAX), i;
> +        for (i = 0; i < open_max; i++) {
> +                close(i);
> +        }
>           return;
>       }
>       /* Avoid closing the directory. */

Do we really need to make the 1M close calls?
The process is on its way to exit anyway...


r~


  reply	other threads:[~2023-06-19  7:00 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-16 15:27 [PATCH v2 0/6] net/tap: Fix QEMU frozen issue when the maximum number of file descriptors is very large Bin Meng
2023-06-16 15:27 ` [PATCH v2 1/6] tests/tcg/cris: Fix the coding style Bin Meng
2023-06-19  6:55   ` Richard Henderson
2023-06-16 15:27 ` [PATCH v2 2/6] tests/tcg/cris: Correct the off-by-one error Bin Meng
2023-06-19  6:55   ` Richard Henderson
2023-06-16 15:27 ` [PATCH v2 3/6] util/async-teardown: Fall back to close fds one by one Bin Meng
2023-06-19  6:59   ` Richard Henderson [this message]
2023-06-16 15:27 ` [PATCH v2 4/6] utils/osdep: Introduce qemu_close_range() Bin Meng
2023-06-19  7:03   ` Richard Henderson
2023-06-19  7:07   ` Richard Henderson
2023-06-16 15:27 ` [PATCH v2 5/6] util/async-teardown: Use qemu_close_range() to close fds Bin Meng
2023-06-19  7:05   ` Richard Henderson
2023-06-16 15:27 ` [PATCH v2 6/6] net: tap: " Bin Meng
2023-06-19  7:08   ` Richard Henderson

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