The patch titled Subject: mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9 has been added to the -mm tree. Its filename is mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrew Shewmaker <agshew@xxxxxxxxx> Subject: mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9 * Explanatory comments for magic numbers in memory notifier Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mmap.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff -puN mm/mmap.c~mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9 mm/mmap.c --- a/mm/mmap.c~mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9 +++ a/mm/mmap.c @@ -3147,6 +3147,13 @@ module_init(init_admin_reserve) /* * Reinititalise user and admin reserves if memory is added or removed. * + * The default user reserve max is 128MB, and the default max for the + * admin reserve is 8MB. These are usually, but not always, enough to + * enable recovery from a memory hogging process using login/sshd, a shell, + * and tools like top. It may make sense to increase or even disable the + * reserve depending on the existence of swap or variations in the recovery + * tools. So, the admin may have changed them. + * * If memory is added and the reserves have been eliminated or increased above * the default max, then we'll trust the admin. * @@ -3162,10 +3169,16 @@ static int reserve_mem_notifier(struct n switch (action) { case MEM_ONLINE: + /* + * Default max is 128MB. Leave alone if modified by operator. + */ tmp = sysctl_user_reserve_kbytes; if (0 < tmp && tmp < (1UL << 17)) init_user_reserve(); + /* + * Default max is 8MB. Leave alone if modified by operator. + */ tmp = sysctl_admin_reserve_kbytes; if (0 < tmp && tmp < (1UL << 13)) init_admin_reserve(); _ Patches currently in -mm which might be from agshew@xxxxxxxxx are include-linux-memoryh-implement-register_hotmemory_notifier.patch mm-limit-growth-of-3%-hardcoded-other-user-reserve.patch mm-replace-hardcoded-3%-with-admin_reserve_pages-knob.patch mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed.patch mm-reinititalise-user-and-admin-reserves-if-memory-is-added-or-removed-v9.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html