The patch titled pid: tighten pidmap spinlock critical section by removing kfree() has been added to the -mm tree. Its filename is pid-tighten-pidmap-spinlock-critical-section-by-removing-kfree.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 *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: pid: tighten pidmap spinlock critical section by removing kfree() From: André Goddard Rosa <andre.goddard@xxxxxxxxx> Avoid calling kfree() under pidmap spinlock, calling it afterwards. Normally kfree() is fast, but sometimes it can be slow, so avoid calling it under the spinlock if we can do it. Signed-off-by: André Goddard Rosa <andre.goddard@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/pid.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN kernel/pid.c~pid-tighten-pidmap-spinlock-critical-section-by-removing-kfree kernel/pid.c --- a/kernel/pid.c~pid-tighten-pidmap-spinlock-critical-section-by-removing-kfree +++ a/kernel/pid.c @@ -141,11 +141,12 @@ static int alloc_pidmap(struct pid_names * installing it: */ spin_lock_irq(&pidmap_lock); - if (map->page) - kfree(page); - else + if (!map->page) { map->page = page; + page = NULL; + } spin_unlock_irq(&pidmap_lock); + kfree(page); if (unlikely(!map->page)) break; } _ Patches currently in -mm which might be from andre.goddard@xxxxxxxxx are linux-next.patch vsprintf-factorize-null-string.patch vsprintf-pre-calculate-final-string-length-for-later-use.patch vsprintf-give-it-some-care-to-please-checkpatchpl.patch vsprintf-use-tolower-whenever-possible.patch vsprintf-reduce-code-size-by-avoiding-extra-check.patch vsprintf-move-local-vars-to-block-local-vars-and-remove-unneeded-ones.patch vsprintf-factor-out-skip_space-code-in-a-separate-function.patch vsprintf-reuse-almost-identical-simple_strtoulx-functions.patch ctype-constify-read-only-_ctype-string.patch string-factorize-skip_spaces-and-export-it-to-be-generally-available.patch string-on-strstrip-first-remove-leading-spaces-before-running-over-str.patch tree-wide-convert-open-calls-to-remove-spaces-to-skip_spaces-lib-function.patch parser-remove-unnecessary-strlen.patch pid-tighten-pidmap-spinlock-critical-section-by-removing-kfree.patch pid-reduce-code-size-by-using-a-pointer-to-iterate-over-array.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