[PATCH] idr: document that idr_for_each may be used under rcu_read_lock()
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From: Brice Goglin on 10 May 2010 13:30 Hello Nadia, In commit f9c46d6ea5ce138a886c3a0f10a46130afab75f5, you converted idr_find() and idr_for_each() to rcu_dereference(). The documentation of idr_find() was updated to say that it may now be called under rcu_read_lock(). But the doc of idr_for_each() still says: "The caller must serialize idr_for_each() vs idr_get_new() and idr_remove()." I might be missing something, but assuming idr_for_each() may also be called under rcu_read_lock(), we need something like the patch below, right? (I just duplicated the doc update of idr_find()) thanks, Brice From 35a05eba9cc16d7fe786a9a7ff17f88fcf8b06e2 Mon Sep 17 00:00:00 2001 From: Brice Goglin <Brice.Goglin(a)inria.fr> Date: Mon, 10 May 2010 18:49:51 +0200 Subject: [PATCH] idr: document that idr_for_each may be used under rcu_read_lock() Since commit f9c46d6ea5ce138a886c3a0f10a46130afab75f5, idr_for_each() may be called under rcu_read_lock(). It does not need serialization against idr_get_new() and idr_remove() anymore. Signed-off-by: Brice Goglin <Brice.Goglin(a)inria.fr> --- lib/idr.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/lib/idr.c b/lib/idr.c index 2eb1dca..7eb435d 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -541,7 +541,8 @@ EXPORT_SYMBOL(idr_find); * We check the return of @fn each time. If it returns anything other * than 0, we break out and return that value. * - * The caller must serialize idr_for_each() vs idr_get_new() and idr_remove(). + * This function can be called under rcu_read_lock(), given that the leaf + * pointers lifetimes are correctly managed. */ int idr_for_each(struct idr *idp, int (*fn)(int id, void *p, void *data), void *data) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |