Re: [PATCH 4/7] aoe: make dynamic block minor numbers the default
On Oct 2, 2012, at 5:17 PM, Andrew Morton wrote: ... >> The static arrangement is still available with aoe_dyndevs=0, and >> the aoe-stat tool from the userland aoetools package, the user >> space counterpart to the aoe driver, recognizes the case where >> there is a mismatch between the minor number in sysfs and the >> minor number in a special device file. > > Oh. There we are. > > Again, what are the back-(in)compatibility issues which users might > encounter with this? I think the people who care about aoe_dyndevs=0 are the people creating an initramfs without udev and with AoE targets that have low shelf and slot numbers for addresses. They might want a tiny bzImage that can boot off AoE storage using device nodes prepared in advance with mknod. The old static mapping is a nice fit for that use case. There could be others with a reason not to use udev, but none of those others have ever communicated with me, if they exist. It's probably confusing the way I did the commits, making static the default before explicitly changing it to dynamic, but usually the people who actually care about this are so technical that I expect them to read the git logs, and I wanted to leave a paper trail there for anyone reading later. -- Ed Cashin ecas...@coraid.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 4/7] aoe: make dynamic block minor numbers the default
On Mon, 1 Oct 2012 19:05:15 -0700 Ed Cashin wrote: > Because udev use is so widespread, making the old static mapping > the default is too conservative, given the severe limitations it > places on usable AoE addresses. Storage virtualization and > larger shelves have made the old limitations too confining. > > These changes make the dynamic block device minor numbers the > default, removing the limitations on usable AoE addresses. > > The static arrangement is still available with aoe_dyndevs=0, and > the aoe-stat tool from the userland aoetools package, the user > space counterpart to the aoe driver, recognizes the case where > there is a mismatch between the minor number in sysfs and the > minor number in a special device file. Oh. There we are. Again, what are the back-(in)compatibility issues which users might encounter with this? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 4/7] aoe: make dynamic block minor numbers the default
On Mon, 1 Oct 2012 19:05:15 -0700 Ed Cashin ecas...@coraid.com wrote: Because udev use is so widespread, making the old static mapping the default is too conservative, given the severe limitations it places on usable AoE addresses. Storage virtualization and larger shelves have made the old limitations too confining. These changes make the dynamic block device minor numbers the default, removing the limitations on usable AoE addresses. The static arrangement is still available with aoe_dyndevs=0, and the aoe-stat tool from the userland aoetools package, the user space counterpart to the aoe driver, recognizes the case where there is a mismatch between the minor number in sysfs and the minor number in a special device file. Oh. There we are. Again, what are the back-(in)compatibility issues which users might encounter with this? -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 4/7] aoe: make dynamic block minor numbers the default
On Oct 2, 2012, at 5:17 PM, Andrew Morton wrote: ... The static arrangement is still available with aoe_dyndevs=0, and the aoe-stat tool from the userland aoetools package, the user space counterpart to the aoe driver, recognizes the case where there is a mismatch between the minor number in sysfs and the minor number in a special device file. Oh. There we are. Again, what are the back-(in)compatibility issues which users might encounter with this? I think the people who care about aoe_dyndevs=0 are the people creating an initramfs without udev and with AoE targets that have low shelf and slot numbers for addresses. They might want a tiny bzImage that can boot off AoE storage using device nodes prepared in advance with mknod. The old static mapping is a nice fit for that use case. There could be others with a reason not to use udev, but none of those others have ever communicated with me, if they exist. It's probably confusing the way I did the commits, making static the default before explicitly changing it to dynamic, but usually the people who actually care about this are so technical that I expect them to read the git logs, and I wanted to leave a paper trail there for anyone reading later. -- Ed Cashin ecas...@coraid.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 4/7] aoe: make dynamic block minor numbers the default
Because udev use is so widespread, making the old static mapping the default is too conservative, given the severe limitations it places on usable AoE addresses. Storage virtualization and larger shelves have made the old limitations too confining. These changes make the dynamic block device minor numbers the default, removing the limitations on usable AoE addresses. The static arrangement is still available with aoe_dyndevs=0, and the aoe-stat tool from the userland aoetools package, the user space counterpart to the aoe driver, recognizes the case where there is a mismatch between the minor number in sysfs and the minor number in a special device file. Signed-off-by: Ed Cashin --- drivers/block/aoe/aoedev.c |2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c index 3d494fd..90e5b53 100644 --- a/drivers/block/aoe/aoedev.c +++ b/drivers/block/aoe/aoedev.c @@ -19,7 +19,7 @@ static void aoedev_freedev(struct aoedev *); static void freetgt(struct aoedev *d, struct aoetgt *t); static void skbpoolfree(struct aoedev *d); -static int aoe_dyndevs; +static int aoe_dyndevs = 1; module_param(aoe_dyndevs, int, 0644); MODULE_PARM_DESC(aoe_dyndevs, "Use dynamic minor numbers for devices."); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 4/7] aoe: make dynamic block minor numbers the default
Because udev use is so widespread, making the old static mapping the default is too conservative, given the severe limitations it places on usable AoE addresses. Storage virtualization and larger shelves have made the old limitations too confining. These changes make the dynamic block device minor numbers the default, removing the limitations on usable AoE addresses. The static arrangement is still available with aoe_dyndevs=0, and the aoe-stat tool from the userland aoetools package, the user space counterpart to the aoe driver, recognizes the case where there is a mismatch between the minor number in sysfs and the minor number in a special device file. Signed-off-by: Ed Cashin ecas...@coraid.com --- drivers/block/aoe/aoedev.c |2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c index 3d494fd..90e5b53 100644 --- a/drivers/block/aoe/aoedev.c +++ b/drivers/block/aoe/aoedev.c @@ -19,7 +19,7 @@ static void aoedev_freedev(struct aoedev *); static void freetgt(struct aoedev *d, struct aoetgt *t); static void skbpoolfree(struct aoedev *d); -static int aoe_dyndevs; +static int aoe_dyndevs = 1; module_param(aoe_dyndevs, int, 0644); MODULE_PARM_DESC(aoe_dyndevs, Use dynamic minor numbers for devices.); -- 1.7.1 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
