Messages in this thread | | | From | Dmitry Vyukov <> | Date | Thu, 17 Dec 2020 11:19:24 +0100 | Subject | Re: [PATCH v3] lib: stackdepot: Add support to configure STACK_HASH_SIZE |
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On Thu, Dec 17, 2020 at 6:42 AM Vijayanand Jitta <vjitta@codeaurora.org> wrote: > > On 12/16/2020 7:04 PM, Alexander Potapenko wrote: > >>> To reiterate, I think you don't need a tunable stack_hash_order > >>> parameter if the only use case is to disable the stack depot. > >>> Maybe it is enough to just add a boolean flag? > >> > >> There are multiple users of stackdepot they might still want to use > >> stack depot but with a lower memory footprint instead of MAX_SIZE > >> so, a configurable size might help here ? > > > > Can you provide an example of a use case in which the user wants to > > use the stack depot of a smaller size without disabling it completely, > > and that size cannot be configured statically? > > As far as I understand, for the page owner example you gave it's > > sufficient to provide a switch that can disable the stack depot if > > page_owner=off. > > > There are two use cases here, > > 1. We don't want to consume memory when page_owner=off ,boolean flag > would work here. > > 2. We would want to enable page_owner on low ram devices but we don't > want stack depot to consume 8 MB of memory, so for this case we would > need a configurable stack_hash_size so that we can still use page_owner > with lower memory consumption. > > So, a configurable stack_hash_size would work for both these use cases, > we can set it to '0' for first case and set the required size for the > second case. > > >>> Or even go further and disable the stack depot in the same place that > >>> disables page owner, as the user probably doesn't want to set two > >>> flags instead of one? > >>> > >> > >> Since, page owner is not the only user of stack depot we can't take that > >> decision of disabling stack depot if page owner is disabled. > > > > Agreed, but if multiple subsystems want to use stackdepot together, it > > is even harder to estimate the total memory consumption. > > How likely is it that none of them will need MAX_SIZE? > > > >>>> Minchan, > >>>> This should be fine right ? Do you see any issue with disabling > >>>> stack depot completely ?
+kasan-dev
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