From: Florian Weimer <fweimer@redhat.com>
To: DJ Delorie <dj@redhat.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [v3] Update mmap() flags and errors lists
Date: Fri, 14 Jun 2024 10:21:46 +0200 [thread overview]
Message-ID: <87tthwszmt.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <xnv82nustr.fsf@greed.delorie.com> (DJ Delorie's message of "Wed, 05 Jun 2024 14:50:56 -0400")
* DJ Delorie:
> +@item MAP_32BIT
> +Require addresses that can be accessed with a 32 bit pointer, i.e.,
> +within the first 4 GiB. Ignored if MAP_FIXED is specified.
Isn't MAP_32BIT mapping within the first 2 GiB?
> +@item MAP_FIXED_NOREPLACE
> +Similar to @code{MAP_FIXED} except the call will fail with
> +@code{EEXIST} if the new mapping would overwrite an existing mapping.
Maybe note that if the kernel does not support MAP_FIXED_NOREPLACE,
the mapping can result at a different address, with no overlap?
> +@item MAP_POPULATE
> +@itemx MAP_NONBLOCK
> +These two are opposites. @code{MAP_POPULATE} is a hint that requests
> +that the kernel read-ahead a file-backed mapping, causing more pages
> +to be mapped before they're needed. @code{MAP_NONBLOCK} is a hint
> +that requests that the kernel @emph{not} attempt such, only mapping
> +pages when they're actually needed.
Maybe mention that even with mlockall or MAP_LOCK, MAP_POPULATE does not
avoid future page faults, and mlock still needs to be used?
> +@code{/proc/sys/vm/max_map_count}.
Either use @file{/proc/sys/vm/max_map_count}, or something like the “the
@code{vm.max_map_count} sysctl setting”.
Thanks,
Florian
next prev parent reply other threads:[~2024-06-14 8:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-10 18:59 DJ Delorie
2024-06-04 22:16 ` Florian Weimer
2024-06-05 4:10 ` DJ Delorie
2024-06-05 6:38 ` Florian Weimer
2024-06-05 18:42 ` DJ Delorie
2024-06-14 8:14 ` Florian Weimer
2024-06-14 16:40 ` DJ Delorie
2024-06-05 18:50 ` [v3] " DJ Delorie
2024-06-14 8:21 ` Florian Weimer [this message]
2024-06-14 18:19 ` DJ Delorie
2024-06-14 18:46 ` [v4] " DJ Delorie
2024-06-18 20:13 ` Mathieu Desnoyers
2024-06-18 20:57 ` DJ Delorie
2024-06-21 13:02 ` Mathieu Desnoyers
2024-06-21 16:17 ` DJ Delorie
2024-06-21 16:20 ` Mathieu Desnoyers
2024-06-19 7:16 ` Florian Weimer
2024-06-05 4:11 ` [v2] " DJ Delorie
2024-06-05 7:44 ` Andreas Schwab
2024-06-05 18:42 ` DJ Delorie
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